Semiconductor equipment

Abstract

We provide a novel semiconductor device. [Solution] A comparison unit that compares two current values, a control unit, and a current output type digital-analyzer. The log conversion unit converts the analog signal to a digital signal using two power units. It has a function to generate a sign bit that indicates the relative magnitude of the current values, and the difference between two current values ​​through successive comparison. It has the function of converting minutes into a digital signal and the function of outputting a sign bit and a digital signal. do.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a semiconductor device.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. The technical field relates to a product, a method, or a method of manufacture. Or, one aspect of the present invention. This refers to a process, machine, manufacture, or composition. This concerns (the tar).

[0003] More specifically, one aspect of the present invention disclosed herein is a technical field of semiconductor devices, Display devices, liquid crystal display devices, light-emitting devices, energy storage devices, imaging devices, memory devices, signal processing devices, pro Sensors, electronic devices, systems, methods for driving them, methods for manufacturing them, or inspections thereof. One example of an investigation method is to give this.

[0004] In this specification, a semiconductor device is defined as a device that can function by utilizing semiconductor properties. This refers to the whole. Therefore, it includes semiconductor elements such as transistors and diodes, and semiconductor elements in general. The circuit is a semiconductor device. It is also used in display devices, light-emitting devices, lighting devices, electro-optical devices, and communications. Devices and electronic equipment may include semiconductor elements or semiconductor circuits. Therefore, Table Display devices, light-emitting devices, illumination devices, electro-optical devices, imaging devices, communication devices, and electronic equipment, etc. It is sometimes called a semiconductor device. [Background technology]

[0005] Analog to Digital (AD) converter converts analog signals to digital signals. AD converters are known. Examples of AD converters include delta-sigma type, pipeline type, and flat type. Examples include the Shu type and the Successive Approximation (SA) type. Various AD conversion devices using different conversion methods have been developed.

[0006] Successive approximation AD converters can achieve 16-bit resolution, consume less power, and... Often used in applications with a pumping frequency of 10 MHz or less. Succession ratio A comparison-type AD converter consists of a comparator and a DA (Digital to Analog) converter. log) conversion unit, and successive comparison register (SAR: Successive Approval) It includes a ximation Register. Patent Document 1 describes two analog signals An AD converter is shown that converts the potential difference between two points into a digital signal. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2019-186842 [Overview of the project] [Problems that the invention aims to solve]

[0008] The AD conversion device shown in Patent Document 1 uses a capacitive array type DA conversion unit. In order to increase resolution, a significant increase in occupied area is unavoidable. In addition, the input signal is If the current is analog, you will need to add a circuit to convert the current signal into a voltage signal.

[0009] One aspect of the present invention aims to provide a semiconductor device with reduced footprint. Alternatively, one aspect of the present invention aims to provide a semiconductor device with reduced power consumption. Alternatively, one aspect of the present invention provides a semiconductor device with improved operational readability. One of the objectives is to provide a novel semiconductor device.

[0010] The problems addressed by one embodiment of the present invention are not limited to those listed above. This does not preclude the existence of other issues. These other issues are described below in this section. This is an issue not mentioned in this section. Issues not mentioned in this section should be discussed in the specification or by those skilled in the art. This can be derived from drawings and other descriptions, and can be extracted as appropriate from these descriptions. Furthermore, one aspect of the present invention addresses at least one of the problems listed above and other problems. This invention solves the problems listed above, and other problems. You don't need to solve all the problems. [Means for solving the problem]

[0011] One aspect of the present invention is a comparison unit that compares the current value of a first signal with the current value of a second signal, and a first digital A semiconductor device comprising a digital-to-analog conversion unit, a second digital-to-analog conversion unit, and a control unit. The comparison unit has the function of comparing the first signal and the second signal to generate an output signal. The control unit has the function of generating code bits according to the output signal and the function of generating a digital signal. It has the function of outputting a sign bit and a digital signal, and the first digital-to-analog converter The conversion unit has a function to add a current of a current value corresponding to the digital signal to the first signal, and the second digital The digital-to-analog conversion section has the function of adding a current of a value corresponding to the digital signal to the second signal. It is a semiconductor device that is equipped with something.

[0012] The sign bit is determined according to the relative magnitudes of the first signal and the second signal. For example, the first signal If the current value is greater than the current value of the second signal, it will be "0", and if not, it will be "1". Good. The digital signal generated by the control unit is determined according to the difference current between the first signal and the second signal. It is possible. Digital signals are, for example, digital values ​​of 8 bits or more and 16 bits or less. That's all you need to do.

[0013] The comparison unit functions as a current-comparative comparator. A semiconductor device according to one aspect of the present invention is It functions as a successive approximation type AD converter. Furthermore, a semiconductor device according to one aspect of the present invention It can also function as a ReLU function. [Effects of the Invention]

[0014] According to one aspect of the present invention, a semiconductor device with reduced footprint can be provided. Alternatively, it is possible to provide a semiconductor device with reduced power consumption. Or, the operating readability can be improved. We can provide an improved semiconductor device. Or, we can provide a novel semiconductor device. It is possible.

[0015] The effects of one embodiment of the present invention are not limited to those listed above. This does not preclude the existence of other effects. These other effects are described below in this section. This is an effect not mentioned in this section. Effects not mentioned in this section can be found in the specification or by those skilled in the art. This can be derived from drawings and other descriptions, and can be extracted as appropriate from these descriptions. Furthermore, one aspect of the present invention includes at least one of the effects listed above and other effects. It has the effect of [this]. Therefore, one aspect of the present invention is the case when the above-listed effects are not present. There are also others. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a diagram illustrating an AD converter. [Figure 2] Figure 2 is a flowchart illustrating the AD converter. [Figure 3] Figure 3 illustrates the sequential comparison operation. [Figure 4] Figure 4 is a diagram illustrating an AD converter. [Figure 5] Figures 5A and 5B illustrate the comparison section. [Figure 6] Figures 6A and 6B illustrate the DA conversion section. [Figure 7] Figures 7A to 7E illustrate the circuits included in the DA conversion section. [Figure 8] Figure 8A is a diagram illustrating the DA conversion section. Figures 8B to 8F are diagrams illustrating the circuits included in the DA conversion section. [Figure 9] Figures 9A and 9B illustrate a hierarchical neural network. [Figure 10] Figures 10A and 10B illustrate semiconductor devices. [Figure 11] Figures 11A and 11B illustrate semiconductor devices. [Figure 12] Figure 12 is a diagram illustrating a semiconductor device. [Figure 13] Figure 13 is a flowchart illustrating an example of the operation of an AD converter. [Figure 14] Figures 14A and 14B illustrate examples of the operation of an AD converter. [Figure 15] Figure 15 illustrates an example of a display device configuration. [Figure 16] Figures 16A and 16B illustrate an example of the configuration of a display device. [Figure 17] Figures 17A and 17B illustrate examples of pixel configurations. [Figure 18]Figures 18A to 18D illustrate examples of the operation of the display element. [Figure 19] Figures 19A and 19B illustrate examples of the operation of the display element. [Figure 20] Figure 20 illustrates an example of the configuration of an AD conversion circuit. [Figure 21] Figure 21 illustrates an example of the operation of an AD conversion circuit. [Figure 22] Figure 22 is a diagram illustrating a semiconductor device. [Figure 23] Figures 23A to 23C show examples of transistor configurations. [Figure 24] Figure 24A illustrates the classification of crystal structures, Figure 24B illustrates the XRD spectrum of crystalline IGZO, and Figure 24C illustrates the micro-electron diffraction pattern of crystalline IGZO. [Figure 25] Figure 25A is a flowchart showing an example of an electronic component manufacturing method, Figure 25B is a top view of a semiconductor wafer, Figure 25C is an enlarged view of a part of a semiconductor wafer, Figure 25D is a schematic diagram of a chip, and Figure 25E is a perspective schematic diagram showing an example of an electronic component configuration. [Figure 26] Figures 26A to 26J show examples of electronic devices. [Figure 27] Figures 27A to 27C illustrate an example of an electronic device. [Figure 28] Figure 28 shows the measurement results of the input / output characteristics of the AD converter. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is as follows Not limited to the description, the present invention may be described in its form and details without departing from the spirit and scope of the present invention. Those skilled in the art will readily understand that the details can be changed in various ways. Therefore, the present invention is described below. The description of the embodiments shown is not to be limited to the stated content. In the diagram, the same reference numeral is used for identical parts or parts having similar functions in different drawings. It will be used consistently throughout, and repeated explanations will be omitted.

[0018] Furthermore, the position, size, and scope of each component shown in the drawings, etc., are intended to facilitate understanding of the invention. Therefore, it may not represent the actual location, size, or range. For this reason, disclosure is required. The invention is not necessarily limited to the location, size, scope, etc. disclosed in the drawings, etc. For example. In the actual manufacturing process, the resist mask may be unintentionally damaged by processes such as etching. While there may be some reduction in value, this is sometimes not reflected in the diagram for the sake of clarity.

[0019] Furthermore, in order to make the explanations easier to understand, some components are omitted from the drawings and other diagrams. It may happen.

[0020] Furthermore, in this specification, the terms "electrode" and "wiring" do not functionally limit these components. It is not that. For example, "electrodes" are sometimes used as part of "wiring," and The reverse is also true. Furthermore, the terms "electrode" and "wiring" refer to multiple "electrodes" and "wirings". This includes cases where they are formed as a single unit.

[0021] Furthermore, in this specification, etc., "terminal" in an electrical circuit means an input or output of current, This refers to the part where pressure is input or output, or where signals are received or transmitted. In some cases, a portion of the wiring or electrodes may function as a terminal.

[0022] In this specification, the terms "above" and "below" refer to the relative positions of the constituent elements, specifically, directly above or directly below. Furthermore, this does not limit the situation to direct contact. For example, "electrode B on insulating layer A" If the expression is "electrode B is formed in direct contact with insulating layer A", then it is not necessary for the insulating layer A to be in direct contact with electrode B. This does not exclude cases that include other components between layer A and electrode B.

[0023] Furthermore, in this specification, "electrically connected" refers to both a direct connection and a "some kind of connection". This includes cases where it is connected via "something that has an electrical effect". Here, "something "A device having an electrical function" is one that enables the exchange of electrical signals between connected objects. If so, there are no particular restrictions. Therefore, even when it is expressed as "electrically connected", In real-world circuits, there may be no physical connections, only prolonged wiring. .

[0024] Furthermore, in this specification and elsewhere, "parallel" means, for example, two straight lines that are at an angle of -10° or more and 10° or less. This refers to a state where objects are positioned at the following angles. Therefore, it also includes cases where the angle is between -5° and 5°. Furthermore, "perpendicular" and "orthogonal" refer to, for example, two lines that are at an angle of 80° or more but less than or equal to 100°. This refers to a state where objects are arranged at an angle. Therefore, it includes cases where the angle is between 85° and 95°.

[0025] Furthermore, in this specification and other documents, regarding count values ​​and measured values, or count values ​​or measured values, Regarding things, methods, and events that can be converted into quantitative values, the terms "identical," "same," and "equal" are used. Or, when we say "uniform," unless otherwise specified, it means plus or minus 20%. This includes errors.

[0026] Furthermore, in this specification, the terms "adjacent" and "proximity" refer to situations where the constituent elements are directly in contact. This does not limit it. For example, the expression "electrode B adjacent to insulating layer A" means insulating It is not necessary for layer A and electrode B to be in direct contact; other components can be used between insulating layer A and electrode B. Do not exclude items that contain the element.

[0027] Furthermore, voltage is the potential difference between a certain potential and a reference potential (e.g., ground potential or source potential). This often indicates that. Therefore, voltage and electric potential are often interchangeable. In this specification, unless otherwise specified, voltage and potential may be used interchangeably. It shall be considered as such.

[0028] Furthermore, even when the term "semiconductor" is used, if, for example, its conductivity is sufficiently low, it can be referred to as an "insulator." It possesses the following characteristics. Therefore, it is also possible to use it by replacing "semiconductor" with "insulator". In this case, the boundary between "semiconductors" and "insulators" is ambiguous, and a strict distinction between the two is difficult. Therefore, the terms "semiconductor" and "insulator" as used herein are interchangeable. It may be possible.

[0029] Furthermore, even when the term "semiconductor" is used, if, for example, its conductivity is sufficiently high, it can be referred to as a "conductor." It possesses the following characteristics. Therefore, it is also possible to use it by replacing "semiconductor" with "conductor". In this case, the boundary between "semiconductors" and "conductors" is ambiguous, and a strict distinction between the two is difficult. Therefore, the terms "semiconductor" and "conductor" as used herein are interchangeable. It may be possible.

[0030] Furthermore, in this specification, "resistive element" refers to, for example, an element having a resistance value higher than 0Ω. It can be a circuit element, wiring, etc. Therefore, in this specification, etc., "resistive element" These include wiring with resistance, transistors through which current flows between source and drain, and diodes. This includes inductors and the like. Therefore, the term "resistor" is used to mean "resistor". This can be rephrased as terms such as "load" or "region with resistance," and conversely, "resistance" or "load" The term "region having resistance" can be replaced with terms such as "resistive element". The resistance value is preferably 1 mΩ or more and 10 Ω or less, more preferably 5 mΩ. It can be between Ω and 5Ω, more preferably between 10mΩ and 1Ω. Also, for example If 1Ω or more, 1 × 10 9 It may also be less than or equal to Ω.

[0031] Furthermore, in this specification, "capacitive element" refers to, for example, an element with a capacitance value higher than 0F. Circuit elements having, regions of wiring having capacitance values ​​higher than 0F, parasitic capacitance, transient This can be the gate capacitance of a sta, etc. Therefore, in this specification, etc., "capacitive element" "This refers not only to a circuit element that includes a pair of electrodes and a dielectric material contained between those electrodes, but also to other circuit elements. Parasitic capacitance between wires, and between the source or drain of a transistor. This includes gate capacitance and other capacitances that occur between the element and the terminal. Also, "capacitive element" and "parasitic capacitance" are also included. Terms like "gate capacity" can be replaced with terms like "capacity," and conversely, The term "capacitance" can be rephrased as "capacitive element," "parasitic capacitance," "gate capacitance," etc. It is possible. Also, the term "a pair of electrodes" in "capacitance" means "a pair of conductors" or "one This can be rephrased as "a pair of conductive regions" or "a pair of regions." Furthermore, the capacitance value is... For example, it can be set to 0.05 fF or more and 10 pF or less. Also, for example, 1 p It may be set to F or above and 10 μF or below.

[0032] Note that, in circuit diagrams, independent components are shown as being electrically connected to each other. Even in such cases, one component may possess the functions of multiple components. For example, if part of the wiring also functions as an electrode, one conductive film will function as the wiring, and It possesses the functions of both components of the electrode. Therefore, in this specification Electrically connected means that a single conductive film combines the functions of multiple components. This also falls under that category.

[0033] Furthermore, in this specification, a transistor is referred to as the gate, source, and drain. It has three terminals. The gate is a control terminal that controls the conduction state of the transistor. The two terminals that function as either the source or drain are the input and output terminals of the transistor. The two input / output terminals specify the conductivity type of the transistor (n-channel type, p-channel type) and the transistor type. Depending on the potential applied to the three terminals of the transistor, one terminal becomes the source and the other becomes the drain. It becomes "in".

[0034] Thus, the source and drain functions differ when using transistors with different polarities. Or, when the direction of current changes during circuit operation, or depending on the operating conditions, they may interact with each other. Because they switch places, it is difficult to determine which is the source and which is the drain. Therefore, in this specification, the terms source and drain shall be used interchangeably. It is assumed that this is possible.

[0035] Furthermore, in this specification and other documents, when describing the connection relationships of transistors, the term "source or drain" is used. "One side of" (or the first electrode, or the first terminal), "the other side of the source or drain" (and The notation (second electrode, or second terminal) is used. Note that the structure of the transistor may vary. In addition to the three terminals mentioned above, it may also have a back gate. In this case, this specification In books and other documents, the gate or back gate of a transistor is referred to as the first gate. The other of the gate or back gate of a transistor is sometimes referred to as the second gate. In the same transistor, the terms "gate" and "back gate" are interchangeable. In some cases, this is possible. Also, if the transistor has 3 or more gates, In the specifications, each gate will be referred to as the first gate, the second gate, the third gate, and so on. It is sometimes referred to as such.

[0036] Furthermore, in this specification, etc., the high power supply potential Vdd (hereinafter simply referred to as "Vdd", "potential H", etc.) (Also called "H") is the low power supply potential Vss (hereinafter simply referred to as "Vss", "potential L", etc.) It indicates a power supply potential that is higher than Vdd (also called "L"). Also, Vss is a power supply potential that is higher than Vdd. It also shows a low potential power supply potential. Furthermore, the ground potential (hereinafter simply referred to as "GND") The potential (also called the electric potential) can also be used as Vdd or Vss. For example, Vdd is grounded. In the case of electric potential, Vss is a potential lower than the ground potential, and if Vss is the ground potential, Vdd is at a higher potential than the ground potential.

[0037] Furthermore, the transistors described herein, unless otherwise explicitly stated, are enhancement transistors. Let's assume it's a normally-off type n-channel field-effect transistor. Therefore, its equation is The voltage value (also called "Vth") shall be greater than 0V. Also, unless otherwise specified... Except in cases where, "supplying a high potential to the gate of a transistor" means "to supply a high potential to the gate of a transistor." It can be synonymous with "to turn on." Also, unless explicitly stated, "transition" "Supplying an inductive potential to the gate of a transistor" is synonymous with "turning the transistor off." There are cases where this is the case.

[0038] Furthermore, in this specification, etc., "gate" refers to part or all of the gate electrode and gate wiring. This refers to the gate wiring of at least one transistor and another transistor. This refers to wiring used to electrically connect poles or other wiring.

[0039] Furthermore, in this specification, etc., "source" refers to the source region, source electrode, and source wiring. This refers to part or all of something. The source region is the part of the semiconductor layer whose resistivity is below a certain value. It refers to a region. The source electrode refers to the conductive layer of the part connected to the source region. Source wiring refers to the source electrode of at least one transistor and another electrode or another This refers to wiring used to electrically connect other wiring.

[0040] Furthermore, in this specification, etc., "drain" refers to the drain region, drain electrode, and drain This refers to part or all of the wiring. The drain region is a part of the semiconductor layer with constant resistivity. This refers to the region below a certain value. The drain electrode is the conductive layer of the part connected to the drain region. This refers to the drain wiring, which is the connection between the drain electrode of at least one transistor and another This refers to wiring used to electrically connect an electrode or another wire.

[0041] Furthermore, in order to make the potential of wiring, electrodes, or conductors easier to understand in drawings and other diagrams, "H" indicates an H potential, or "L" indicates an L potential, adjacent to wiring, electrodes, or conductors. In some cases, the following may be added: Also, if some circuits are not functioning, the following may be added to those circuits. The symbol "×" may be added.

[0042] Furthermore, in this specification, when the same reference numeral is used for multiple elements, we will not specifically distinguish them. When necessary, use symbols such as "a", "A", "_1", "_2", "[m,n]", etc. In some cases, identification codes may be added to the description. For example, one of two wiring GLs may be labeled as wiring G Sometimes, one side is labeled "La" and the other "GLb" (wiring).

[0043] Furthermore, in this specification, ordinal numbers such as "the first," "the second," etc., are used to avoid confusion of constituent elements. It is something that is attached to the eye and does not indicate any order or rank, such as the order of processes or the order of stacking. There are none. Furthermore, even if a term is not given an ordinal number in this specification, the constituent elements are To avoid confusion, ordinal numbers may be used in the claims. Even if a term is given an ordinal number in a book or other document, a different ordinal number may be used in the patent claims. In some cases, words may be attached. Also, in this specification, etc., terms to which ordinal numbers are attached. However, ordinal numbers may be omitted in patent claims and other documents.

[0044] Furthermore, if it is stated in this specification, etc., that X and Y are connected, then X and Y When X and Y are electrically connected, and when X and Y are functionally connected, Cases where they are directly connected are disclosed in this specification, etc. Therefore, This includes not only fixed connection relationships, such as those shown in a diagram or text, but also those shown in a diagram or text. Other connections besides those shown are also disclosed in the diagram or text. X and Y are, Assume that it is an object (such as a device, element, circuit, wiring, electrode, terminal, conductive film, layer, etc.) .

[0045] As an example of the case where X and Y are electrically connected, an element (such as a switch, transistor, capacitor, inductor, resistor, diode, display device, light-emitting device, load, etc.) that enables the electrical connection between X and Y can be connected by one or more between X and Y. Note that the switch has a function of controlling the on-state and off-state. That is, the switch can be in a conductive state (on-state) or a non-conductive state (off-state), and has a function of controlling whether to allow current to flow or not.

[0046] As an example of the case where X and Y are functionally connected, a circuit (such as a logic circuit (inverter, NAND circuit, NOR circuit, etc.), signal conversion circuit (digital-analog conversion circuit, analog-digital conversion circuit, gamma correction circuit, etc.), potential level conversion circuit (power supply circuit (boost circuit, buck circuit, etc.), level shifter circuit that changes the potential level of a signal, etc.), voltage source, current source, switching circuit, amplifier circuit (circuit that can increase the signal amplitude or current amount, operational amplifier, differential amplifier circuit, source follower circuit, buffer circuit, etc.), signal generation circuit, memory circuit, control circuit, etc.) can be connected by one or more between X and Y. Note that as an example, even if there is another circuit between X and Y, when the signal output from X is transmitted to Y, X and Y are considered to be functionally connected.

[0047] When it is explicitly described that X and Y are electrically connected, X and Y are electrically ​​​​​​​​​​when connected in a certain way (that is, connected with another element or another circuit sandwiched between X and Y ), and when X and Y are directly connected (that is, connected without another element or another circuit sandwiched between X and Y).

[0048] Also, for example, it can be expressed as "X, Y, the source (or the first terminal, etc.) of the transistor, and the drain ( or the second terminal, etc.) of the transistor are electrically connected to each other, and X, the source of the transistor (or the first terminal, etc.), the drain of the transistor (or the second terminal, etc.), and Y are electrically connected in this order." Or it can be expressed as "The source (or the first terminal, etc.) of the transistor is electrically connected to X, and the drain ( or the second terminal, etc.) of the transistor is electrically connected to Y, and X, the source of the transistor (or the first terminal, etc.), the drain of the transistor (or the second terminal, etc.), and Y are electrically connected in this order." Or it can be expressed as "X is electrically connected to Y through the source (or the first terminal, etc.) and the drain ( or the second terminal, etc.) of the transistor, and X, the source of the transistor (or the first terminal, etc.), the drain of the transistor (or the second terminal, etc.), and Y are provided in this connection order." By stipulating the connection order in the circuit configuration using an expression method similar to these examples, the source (or the first terminal, etc.) of the transistor and the drain (or the second terminal, etc.) of the transistor can be distinguished to determine the technical scope. Note that these expression methods are just examples and are not limited to these expression methods. Here, X and Y are distinguished, and the technical scope can be determined. These expression methods are just examples and are not limited to these expression methods. Here, X and Y are examples, and are not limited to these expression methods. Here, X and Y are The object in question (for example, a device, element, circuit, wiring, electrode, terminal, conductive film, layer, etc.) do.

[0049] Furthermore, in this specification, a transistor is referred to as the gate, source, and drain. It has three terminals. The gate is a control terminal that controls the conduction state of the transistor. The two terminals that function as either the source or drain are the input and output terminals of the transistor. The two input / output terminals specify the conductivity type of the transistor (n-channel type, p-channel type) and the transistor type. Depending on the potential applied to the three terminals of the transistor, one terminal becomes the source and the other becomes the drain. Therefore, in this specification, the terms source and drain are used interchangeably. It may be rephrased. Furthermore, in this specification, the connection relationships of transistors are defined as When explaining, use "either the source or the drain" (or the first electrode or the first terminal), The notation "the other side of the source or drain" (or second electrode, or second terminal) is used. Furthermore, depending on the transistor structure, in addition to the three terminals mentioned above, a back gate may also be used. It may have. In this case, in this specification, etc., the gate or back of the transistor One side of the gate is referred to as the first gate, and the other side of the gate or back gate of the transistor is referred to as the first gate. It is sometimes referred to as the second gate. Furthermore, in the same transistor, there are "gate" and "gate The terms "clock gate" can sometimes be interchanged. Also, transistors If there are three or more gates, in this specification, each gate is referred to as the first gate. It is sometimes referred to as Gate 2, Gate 3, etc.

[0050] Furthermore, in this specification, the "on state" of a transistor refers to the source and This refers to a state where the drain can be considered electrically short-circuited (also called a "conductive state"). Furthermore, the "off state" of a transistor means that the source and drain of the transistor are electrically disconnected. This refers to a state in which a device can be considered to be conducting (also called a "non-conductive state").

[0051] Furthermore, in this specification, "on-current" refers to the current when the transistor is in the ON state and the source is connected to the transistor. It can also refer to the current flowing between the drains. Furthermore, "off-current" refers to the current flowing between the drains of a transistor. It can also refer to the current flowing between the source and drain when the circuit is in a faulty state.

[0052] Furthermore, in this specification, "node" refers to an end node, depending on the circuit configuration or device structure, etc. These terms can be rephrased as sub-units, wiring, electrodes, conductive layers, conductors, impurity regions, etc. Terminals, wiring, etc., can be referred to as nodes.

[0053] Furthermore, in this specification, "voltage" and "potential" may be used interchangeably as appropriate. "Pressure" refers to the potential difference from a reference potential. For example, if the reference potential is grounded... If we consider it as electric potential (ground potential), then "voltage" can be replaced with "electric potential." The wind potential does not necessarily mean 0V. Also, potential is relative. When the reference potential changes, the potential applied to the wiring, the electricity applied to the circuit, etc. The potentials output from circuits and other sources also change.

[0054] "Electric current" refers to the phenomenon of electric charge movement (electrical conduction), for example, "electricity of a positively charged body." The statement "conduction is occurring" means "electrical conduction of a negatively charged body is occurring in the opposite direction." It can be paraphrased. Therefore, in this specification and the like, unless otherwise specified, the term "current" refers to the phenomenon of charge movement (electrical conduction) accompanying the movement of carriers. Here, the carriers include electrons, holes, anions, cations, complex ions, etc., and the carriers vary depending on the system through which the current flows (e.g., semiconductors, metals, electrolytic solutions, vacuum, etc.). Also, in wires etc., the "direction of current" is defined as the direction in which positive carriers move, and it is described with a positive current amount. In other words, the direction in which negative carriers move is opposite to the direction of current, and it is expressed with a negative current amount. Therefore, in this specification and the like, when there is no specification regarding the positive or negative of the current (or the direction of current), descriptions such as "a current flows from element A to element B" can be paraphrased as "a current flows from element B to element A", etc. Also, descriptions such as "a current is input into element A" can be paraphrased as "a current is output from element A", etc. shall be considered possible.

[0055] Also, in this specification and the like, ordinal numbers such as "first", "second", and "third" are attached to avoid confusion of components. Therefore, they do not limit the number of components. Also, they do not limit the order of components. For example, in one embodiment of this specification and the like, the component referred to as "first" may be the component referred to as "second" in other embodiments or in the claims. Also, for example, in one embodiment of this specification and the like, the component referred to as "first" may be omitted in other embodiments or in the claims.

[0056] Also, the terms "upper" and "lower" refer to the positional relationship where one component is directly above or It does not limit the meaning to what is being done. For example, if the expression is "electrode B on insulating layer A", It is not necessary for electrode B to be in direct contact with insulating layer A, but rather between insulating layer A and electrode B. This does not exclude those that include other components.

[0057] Furthermore, the relative positions of the constituent elements change appropriately depending on the direction in which each element is depicted. Therefore, the terminology is not limited to what is explained in the specification, etc., and can be appropriately rephrased depending on the situation. For example, in this specification, phrases indicating placement such as "above" and "below" are used in the composition. In some cases, the positional relationships of elements are used for convenience when explaining them by referring to the drawing. In the expression "insulator located on the upper surface of the conductor," the orientation of the diagram shown should be rotated 180 degrees. By rephrasing it, it can be described as "an insulator located on the underside of a conductor." Also, in the expression "insulator located on the upper surface of the conductor," rotate the orientation of the diagram shown by 90 degrees. By doing so, it can be rephrased as "an insulator located on the left (or right) side of the conductor." It is possible.

[0058] Similarly, in this specification, terms such as "overlapping" refer to the stacking order or other state of the constituent elements. It is not limited to this. For example, if the expression is "electrode B overlapping insulating layer A", then it would mean "insulating layer This is not limited to the state where "electrode B is formed on top of A," but also includes the state where "electrode B is formed beneath insulating layer A." The state is either "there is" or "electrode B is formed on the right (or left) side of insulating layer A". Do not exclude [the following].

[0059] Furthermore, in this specification, terms such as "film" and "layer" may be interchanged depending on the context. It is possible to change the term "conductive layer" to "conductive film". In some cases, this may be possible. Or, for example, the term "insulating film" may be changed to "insulating layer." It may be possible to change the term to this. Or, depending on the circumstances, or depending on the situation. Accordingly, it is possible to replace terms such as "membrane" and "layer" with other terms. For example, change the term "conductive layer" or "conductive film" to the term "conductor." In some cases, this may be possible. Or, for example, the terms "insulating layer" and "insulating film" may be changed to "insulating layer." In some cases, the term can be changed to "body".

[0060] Furthermore, in this specification, terms such as "electrode," "wiring," and "terminal" refer to these components. It is not functionally limited. For example, "electrodes" can be used as part of "wiring". And so the reverse is also true. Furthermore, the terms "electrode" and "wiring" are multiple This also includes cases where the "electrode" and "wiring" are formed as a single unit. Furthermore, for example, The term "terminal" can be used as part of "wiring" or "electrode," and vice versa. It appears that... Furthermore, the term "terminal" refers to a combination of multiple "electrodes," "wirings," and "terminals." This also includes cases where it is formed in such a way. For example, "electrode" is "wiring" or "terminal". It can be part of "wire" or "electrode", and for example, "terminal" can be part of "wiring" or "electrode". It is possible. Also, terms such as "electrode," "wiring," and "terminal" can be used in some cases. Terms such as "region" may be used as substitutes.

[0061] Furthermore, in this specification, terms such as "wiring," "signal line," and "power line" may be used in some cases. Depending on the situation, they can be interchanged. For example, "wiring" In some cases, it is possible to change the term "signal line" to "signal line". Also, for example In some cases, the term "wiring" can be changed to terms such as "power lines." Conversely, terms such as "signal line" and "power line" should be changed to the term "wiring." In some cases, this may be possible. Terms such as "power lines" should be changed to terms such as "signal lines." In some cases, this is possible. Conversely, terms like "signal line" can also be used for "power line." It may be possible to change the terminology. Also, the "potential" applied to the wiring Depending on the situation, or in some cases, the term may be changed to a term such as "signal." In some cases, this is possible. Conversely, terms like "signal" and "electric potential" are also possible. It may be possible to change the terminology.

[0062] In this specification, semiconductor impurities refer to, for example, components other than the main components that make up the semiconductor. For example, elements with a concentration of less than 0.1 atomic percent are considered impurities. The presence of impurities can lead to... For example, the defect level density of semiconductors increases, carrier mobility decreases, and This can occur if the semiconductor is an oxide semiconductor. In this case, impurities that alter the properties of semiconductors include, for example, Group 1 elements, Group 2 elements, and Group 1 elements. These include Group 13 elements, Group 14 elements, Group 15 elements, and transition metals other than the main components, and in particular, for example... For example, hydrogen (also found in water), lithium, sodium, silicon, boron, phosphorus, and carbon. Examples include nitrogen. Specifically, if the semiconductor is silicon, the properties of the semiconductor can be changed. Examples of impurities include, for example, Group 1 elements, Group 2 elements, and Group 13 elements, excluding oxygen and hydrogen. This includes elements from Group 15, among others.

[0063] In this specification, a switch refers to a conductive state (on state) or a non-conductive state (off state). It refers to a device that has the function of controlling whether or not to allow current to flow (in a certain state). Alternatively, A switch is a device that has the function of selecting and switching the path through which electric current flows. This can use electrical switches, mechanical switches, etc. It can be anything that can control the current, and is not limited to any specific type.

[0064] An example of an electrical switch is a transistor (for example, a bipolar transistor, M OS transistors, diodes (for example, PN diodes, PIN diodes, etc.), Schottky diode, MIM (Metal Insulator Metal) diode Code, MIS (Metal Insulator Semiconductor) Dio Logic circuits (such as diode-connected transistors) or combinations thereof. There is. Furthermore, when using a transistor as a switch, the "conductivity state" of the transistor... This refers to a state where the source and drain electrodes of a transistor can be considered to be electrically short-circuited. It refers to a state. Also, the "non-conductive state" of a transistor is when the source electrode and the drive of the transistor are not connected. This refers to a state in which the input electrode can be considered electrically isolated. Note that a transistor is not simply a transistor. When operating as a switch, the polarity (conductivity type) of the transistor is not particularly limited.

[0065] One example of a mechanical switch is MEMS (Micro-Electro-Mechanical Systems). There is a switch that uses Thames technology. This switch is a switch that can be moved mechanically. It has electrodes, and operates by controlling the transition between conductivity and non-conductivity through the movement of these electrodes.

[0066] In this specification, "parallel" means that two straight lines are positioned at an angle of -10° or more and 10° or less. This refers to a state where the temperature is in a certain condition. Therefore, it also includes cases where the temperature is between -5° and 5°. "Parallel" or "approximately parallel" means that two straight lines are positioned at an angle of -30° or more and 30° or less. It refers to a state in which two lines are aligned at an angle of 80° to 100°. This refers to the state in which something is placed. Therefore, it also includes cases where the angle is between 85° and 95°. Also, "Approximately perpendicular" or "roughly perpendicular" means that two lines are positioned at an angle of 60° to 120°. This refers to a state in which something is being done.

[0067] Furthermore, in this specification and other documents, regarding count values ​​and measured values, or count values ​​or measured values, Regarding objects or methods that can be converted into quantitative values, "identical," "same," "equal," or " When we say "uniform," unless otherwise specified, it includes a margin of error of plus or minus 20%. It shall be assumed.

[0068] In this specification, metal oxide refers to metals in a broad sense. It is an oxide. Metal oxides are oxide insulators and oxide conductors (including transparent oxide conductors). Oxide semiconductors (also called OS) They are classified into the following categories. For example, when a metal oxide is used in the active layer of a transistor, the metal acid These oxides are sometimes called oxide semiconductors. In other words, metal oxides have amplification and rectification effects. and a channel formation region of a transistor having at least one switching action If possible, the metal oxide is used as a metal oxide semiconductor (metal oxide semiconductor). It can be called an iconductor. It can also be written as "OS transistor". In such cases, it can be rephrased as a transistor having a metal oxide or oxide semiconductor. It is possible.

[0069] Furthermore, in this specification, metal oxides containing nitrogen are also referred to as metal oxides (metal oxi They are sometimes collectively referred to as (de) metal oxides (met It may also be called al oxynitride.

[0070] Furthermore, in this specification, the configurations shown in each embodiment may be adapted to the configurations shown in other embodiments. These can be combined as appropriate to form one embodiment of the present invention. Also, in one embodiment, If multiple configuration examples are provided, it is possible to combine them as appropriate.

[0071] Furthermore, the content described in one embodiment (even a part of it) may vary depending on the form of its implementation. Another statement (even a partial statement) described in the same manner, and one or more other embodiments described in the same manner. Apply to, combine with at least one of the contents (even if only a part of it) Alternatively, replacements can be made.

[0072] Furthermore, the contents described in each embodiment (or example) refer to the following: This refers to content described using various diagrams or text included in the specification. That is the case.

[0073] Furthermore, a diagram (even a partial one) described in one embodiment may refer to another part of that diagram. Further diagrams (or even just a part of them) described in that embodiment, and one or more other embodiments For at least one figure (even a part of it) described in the form, By doing so, it becomes possible to construct even more diagrams.

[0074] Embodiments described herein will be explained with reference to the drawings. However, the embodiments will be described with reference to the drawings. The practice can be implemented in many different ways, and it may deviate from its purpose and scope. It is easily understood by those skilled in the art that its form and details can be changed in various ways. Therefore, the present invention is not to be interpreted as being limited to the embodiments described herein. In the configuration of the embodiment of the invention, the same part or parts having similar functions are marked with the same reference numeral. The same numbering system is used across different drawings, and explanations of its repetition may be omitted. To make the planes easier to understand, some of the components are not shown in perspective views or top views. Some parts may be omitted.

[0075] Furthermore, in this specification, block diagrams classify components according to their function and treat them as independent of each other. It is shown as a block. However, in actual circuits, the components are arranged according to their function. It is difficult to separate the functions, and multiple functions are involved in one circuit or span multiple circuits. In some cases, one function may be involved. Therefore, the blocks in the block diagram are specified in the specification. The components described are not limited to those explained, and can be appropriately rephrased depending on the situation.

[0076] Furthermore, in drawings and other documents, size, layer thickness, or area may be exaggerated for clarity. There may be cases where this is the case. Therefore, it is not necessarily limited to its size and aspect ratio. The surface is a schematic representation of an ideal example and is not limited to the shape or values ​​shown in the drawing. None. For example, it can include variations in signals, voltages, or currents due to noise, or variations in signals, voltages, or currents due to timing misalignment, etc.

[0077] (Embodiment 1) The AD conversion device (analog-digital conversion device) 100 according to one aspect of the present invention will be described with reference to the drawings. using.

[0078] <Configuration example of AD conversion device 100> Fig. 1 shows a block diagram of the AD conversion device 100. The AD conversion device 100 includes a comparison unit 110, a control unit 120, a DA conversion unit (digital-analog conversion unit) 130a, and a DA conversion unit 13 0b. Also, a wiring 101a is electrically connected to an input terminal 111a of the comparison unit 110, and a wiring 101b is electrically connected to an input terminal 111b of the comparison unit 110.

[0079] The comparison unit 110 has a function of comparing the value of the current flowing through the input terminal 111a with the value of the current flowing through the input terminal 111b and supplying one of the two potentials to the output terminal D. For example, when a current Ia flows through the input terminal 111a via the wiring 101a and a current Ib flows through the input terminal 111b via the wiring 10 1b. Considering the case where the current value of the current Ia exceeds the current value of the current Ib, the comparison unit 110 supplies a potential H to the output terminal D as an output. Also, when the current value of the current Ia is less than or equal to the current value of the current Ib, the comparison unit 110 supplies a potential L to the output terminal D as an output. Also, the output of the comparison unit 110 is input to the control unit 120 via the output terminal D. forced.

[0080] The control unit 120 includes a code generation unit 121 and a digital signal generation unit 122. The code generation unit 1 ​21 has the function of generating a 1-bit sign bit according to the output of the comparison unit 110. Example For example, if the output of the comparison unit 110 is at a potential of H, it generates "0" as the sign bit. Furthermore, if the output of the comparison unit 110 is at a potential of L, a sign bit of "1" is generated. The sign bit is "1" when the output of the comparison unit 110 is at potential H, and "0" when the potential is L. It's okay to have it.

[0081] The digital signal generation unit 122 generates digital values ​​with a resolution of 8 bits or more and 16 bits or less. It has the function of generating digital signals. While lower resolution results in lower AD conversion accuracy, A The D conversion speed can be increased. Higher resolution results in higher AD conversion accuracy, but AD The conversion speed will be slower. Note that the resolution of the digital signal generation unit 122 is 8 bits or more, up to 16 bits. It is not limited to 7 bits or less. The resolution of the digital signal generation unit 122 is 7 bits or less. However, 17 bits or more is also acceptable. The resolution should be determined appropriately according to the purpose and application. good.

[0082] In this embodiment, the digital signal generation unit 122 generates a digital signal with a resolution of 8 bits. This shall be done. Furthermore, in this specification and other documents, each digit of a digital signal shown in binary is This is sometimes referred to as a "bit".

[0083] The control unit 120 processes the digital signal generated by the digital signal generation unit 122 into the DA conversion unit 13 It has the function of supplying 0 (DA conversion unit 130a and / or DA conversion unit 130b). Furthermore, the control unit 120 outputs (OUT) a signal to the outside, which is a digital signal with a code bit added to it. It has the function of doing so. If the resolution of the digital signal is 8 bits, then 1 bit of the sign bit It can output a 9-bit signed digital signal externally, including the control unit. 120 is a successive approximation register (SAR). It functions as an ion register.

[0084] The DA conversion unit 130 is a current output type DAC (Digital to Analog Converter). It functions as a verter. In other words, the DA conversion unit 130 is supplied from the control unit 120. The current corresponding to the digital signal is output to output terminal C (output terminal Ca and / or output terminal It has the function of outputting a child Cb.

[0085] In Figure 1, the output terminal Ca of the DA conversion unit 130a is connected to the comparison unit 110 via node NDa. It is electrically connected to input terminal 111a. Therefore, the output current of the DA conversion unit 130a is The current is added to the input terminal 111a of the comparison unit 110. That is, the current is added to the input terminal 111a. The output current of Ia and the DA conversion unit 130a flows. In other words, the current Ia flows through the DA conversion unit 1 The current obtained by adding the output current of 30a flows through input terminal 111a.

[0086] Furthermore, in Figure 1, the output terminal Cb of the DA conversion unit 130b is connected to the comparison unit 1 via node NDb. It is electrically connected to input terminal 111b of unit 10. Therefore, the output of DA conversion unit 130b The current is added to the input terminal 111b of the comparison unit 110. That is, the current is added to the input terminal 111b. The current Ib and the output current of the DA converter 130b flow through it. In other words, the current Ib and the DA converter... The current obtained by adding the output current of the conversion unit 130b flows to the input terminal 111b.

[0087] Note that node NDA consists of the output section of the DA conversion unit 130a, wiring 101a, and input terminal 1 Node 11a is the node to be electrically connected. Also, node NDb is the node to which the output section of DA conversion unit 130b, wiring 101b, and input terminal 111b are electrically connected.

[0088] <Operation Example of AD Conversion Device 100> FIG. 2 is a flowchart for explaining an operation example of the AD conversion device 100. In the present embodiment, the resolution of the digital signal generated by the digital signal generation unit 122 is set to 8 bits, and the step of the output current of the DA conversion unit 130 is set to 1 nA. Here, the operation of converting the difference value between current Ia and current Ib (also referred to as "differential current") into a digital signal with a sign bit will be described.

[0089] [Step S201] The reset operation of the control unit 120 is performed. Specifically, an 8-bit digital signal is set to (000 00000)2. Also, the digital signal is supplied to the DA conversion unit 130a and the DA conversion unit 130b. Therefore, the outputs of the DA conversion unit 130a and the DA conversion unit 130b stop.

[0090] [Step S202] The current value of current Ia and the current value of current Ib are compared by the comparison unit 110. In the present embodiment, when the current value of current Ia is greater than the current value of current Ib (Yes), the comparison unit 110 supplies a potential H to the output terminal D. Also, when the current value of current Ia is less than or equal to the current value of current Ib (No), the comparison unit 110 supplies a potential L to the output terminal D.

[0091] [Step S203a] When the comparison unit 110 outputs a potential H in step S202, "0" is set to the sign bit.

[0092] [Step S204a] If the sign bit is "0", successive comparison (SA) is performed using the DA conversion unit 130b. During the SA period, the DA conversion unit 130a receives (00000000)2 as a digital signal. Leave the power supply on. Alternatively, you may stop the power supply to the DA conversion unit 130a. Power consumption can be reduced by stopping the power supply to the A conversion unit 130a. We will explain the operation later.

[0093] [Step S203b] If the comparison unit 110 outputs a potential L in step S202, set the sign bit to "1". ru.

[0094] [Step S204b] If the sign bit is "1", SA is performed using the DA conversion unit 130a. SA period Inside, the DA conversion unit 130b is supplied with (00000000)2 as a digital signal. Alternatively, the power supply to the DA conversion unit 130b may be stopped. DA conversion unit 13 By stopping the power supply to 0b, power consumption can be reduced.

[0095] [Step S205] After the completion of step S204a or step S204b, the obtained digital signal and code bit The sign bit is combined to generate a signed digital signal. It could be the most significant bit or the least significant bit.

[0096] For example, if the sign bit is "1" and the digital signal obtained by SA is (01001 If it is 011)2, the sign bit is set to the most significant bit (MSB: Most Significant Bit). Used as the sign bit, it signals a signed digital signal (101001011)2 Alternatively, the sign bit may be set to the least significant bit (LSB). It is used as a cant bit and a signed digital signal (010010111)2 You may do so.

[0097] [Step S206] The generated signed digital signal is output externally. The sign bit "0" is considered positive, and the sign bit When "1" is considered negative, the AD converter 100 according to one aspect of the present invention converts a positive digital signal It can output a positive or negative digital signal. Or, an AD conversion device according to one aspect of the present invention. 100 represents the relative magnitudes of currents Ia and Ib, and the absolute value of the difference between them as a digital signal. It can be output as follows.

[0098] <Example of sequential comparison operation> Figure 3 is used to explain the sequential comparison operation corresponding to step S204b. In Figure 3, the period During periods T1 through T8, the currents Ia and Ib, output terminal D, and digital signals This indicates the state of the digits (Q0 bits to Q7 bits). As mentioned above, digital signal generation The resolution of the digital signal generated by section 122 is set to 8 bits, and the output current of the DA conversion section 130 Let the step size be 1nA. Here, if current Ia is 75nA and current Ib is 150nA... This will be explained. Note that the potential of output terminal D before successive comparison operation (initial state) is potential L. Also, the initial digital signal is (00000000)2.

[0099] [Period T1] During period T1, the Q7 bit, which is the MSB of the digital signal, is set to "1". That is, A digital signal (10000000)2 is generated. This digital signal is then converted by the DA conversion unit 13. It is input to 0a, and 128nA is output from the DA conversion unit 130a. This output is at node N It is supplied to input terminal 111a via Da. Therefore, 203nA is supplied to input terminal 111a. A current of (75 + 128 nA) flows. 150 nA flows through input terminal 111b. Therefore, the potential at output terminal D becomes potential H.

[0100] If the potential of output terminal D changes from the initial potential during period T1, then from period T1 onward... The Q7 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T1. Set the Q7 bit to "1" until [a certain point]. In this embodiment, after period T1, the Q7 bit is "0". That is the case.

[0101] [Period T2] During period T2, set the Q6 bit, which is one bit below the MSB of the digital signal, to "1". That is, it generates the digital signal (01000000)2. This digital signal is D The A-conversion unit 130a receives input, and the DA-conversion unit 130a outputs 64nA. This is supplied to input terminal 111a via node NDA. Therefore, input terminal 111a receives A current of 139nA (75+64nA) flows, and the potential at output terminal D is the same as the initial potential L. That is the case.

[0102] If the potential of output terminal D changes from the initial potential during period T2, then from period T2 onward... The Q6 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T2. Set the Q6 bit to "1" until [a certain point]. In this embodiment, after period T2, the Q6 bit is "1". That is the case.

[0103] [Period T3] During period T3, set the Q5 bit, which is two bits below the MSB of the digital signal, to "1". That is, it generates the digital signal (01100000)2. This digital signal is D The A-conversion unit 130a receives input, and the DA-conversion unit 130a outputs 96nA (64+32nA). The output is supplied to input terminal 111a via node NDA. A current of 171nA (75+64+32nA) flows through power terminal 111a, and the current at output terminal D The position becomes electric potential H.

[0104] If the potential of output terminal D changes from the initial potential during period T3, then from period T3 onward... The Q5 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T3. Set the Q5 bit to "1" until [a certain point]. In this embodiment, after period T3, the Q5 bit is "0". That is the case.

[0105] [Period T4] During period T4, set the Q4 bit, which is 3 bits below the MSB of the digital signal, to "1". That is, it generates the digital signal (01010000)2. This digital signal is D The input is passed to the A conversion unit 130a, and 80nA (64+16nA) is output from the DA conversion unit 130a. The output is supplied to input terminal 111a via node NDA. A current of 155nA (75+64+16nA) flows through power terminal 111a, and the current at output terminal D The position becomes electric potential H.

[0106] If the potential of output terminal D changes from the initial potential during period T4, then from period T4 onward... The Q4 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T4. Set the Q4 bit to "1" until [a certain point]. In this embodiment, after period T4, the Q4 bit is "0". That is the case.

[0107] [Period T5] During period T5, set the Q3 bit, which is 4 bits below the MSB of the digital signal, to "1". That is, it generates the digital signal (01001000)2. This digital signal is D The A-conversion unit 130a receives input, and the DA-conversion unit 130a outputs 72nA (64+8nA). The output is supplied to input terminal 111a via node NDA. A current of 147nA (75+64+8nA) flows through terminal 111a, and the potential of output terminal D is The potential becomes L.

[0108] If the potential of output terminal D changes from the initial potential during period T5, then from period T5 onward... The Q3 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T5. Set the Q3 bit to "1" until [a certain point]. In this embodiment, after period T5, the Q3 bit is "1". That is the case.

[0109] [Period T6] During period T6, set the Q2 bit, which is 5 bits below the MSB of the digital signal, to "1". That is, it generates the digital signal (01001100)2. This digital signal is D The A conversion unit 130a receives input, and the DA conversion unit 130a converts 76nA (64+8+4nA) The output is then supplied to input terminal 111a via node NDA. Therefore, A current of 151nA (75+64+8+4nA) flows through input terminal 111a, and output terminal D The potential becomes potential H.

[0110] If the potential of output terminal D changes from the initial potential during period T6, then from period T6 onward... The Q2 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T6. Set the Q2 bit to "1" until [a certain point]. In this embodiment, after period T6, the Q2 bit is "0". That is the case.

[0111] [Period T7] During period T7, set the Q1 bit, which is 6 bits below the MSB of the digital signal, to "1". That is, it generates the digital signal (01001010)2. This digital signal is D The A conversion unit 130a receives input, and the DA conversion unit 130a converts 74nA (64+8+2nA) The output is then supplied to input terminal 111a via node NDA. Therefore, A current of 149nA (75+64+8+2nA) flows through input terminal 111a, and output terminal D The potential becomes potential L.

[0112] If the potential of output terminal D changes from the initial potential during period T7, then from period T7 onward... The Q1 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T7. Set the Q1 bit to "1" until [a certain point]. In this embodiment, after period T7, the Q1 bit is "1". That is the case.

[0113] [Period T8] During period T8, the Q0 bit, which is the LSB of the digital signal, is set to "1". That is, The digital signal (01001011)2 is generated. The DA conversion unit 13 It is input to 0a, and 75nA (64+8+2+1nA) is output from the DA converter 130a. The output is supplied to input terminal 111a via node NDA. A current of 150nA (75+64+8+2+1nA) flows through 111a, and the current at output terminal D The position becomes electric potential L.

[0114] If the potential of output terminal D changes from the initial potential during period T8, then from period T8 onward... The Q0 bit is set to "0" until the control unit 120 is reset. If the potential does not change from the initial state, the control unit 120 is reset after period T8. Set the Q0 bit to "1" until [a certain point]. In this embodiment, the Q0 bit is "1" from period T8 onward. That is the case.

[0115] In this way, by comparing sequentially from MSB to LSB, the difference current between current Ia and current Ib can be determined. This 75nA can be converted into a digital signal (01001011)2.

[0116] Furthermore, regarding the successive comparison operation corresponding to step S204a, in the above explanation, Replace position H with potential L, replace DA conversion unit 130a with DA conversion unit 130b, etc. You'll understand once you see it.

[0117] Furthermore, in this embodiment, the step size of the output current of the DA conversion unit 130 is set to 1nA, so the maximum It can convert differential currents up to 255nA into digital signals. The output current of the DA conversion unit 130 By increasing the step size, it is possible to handle larger differential currents. For example, DA converter By setting the output current step of the exchange unit 130 to 2nA, the differential current up to a maximum of 510nA can be used. It can be converted to a digital signal.

[0118] Furthermore, to increase the resolution of the digital signal, or to change the step size of the output current of the DA conversion unit 130 By reducing the size, or both, more precise AD conversion can be achieved.

[0119] For example, using the AD converter 190 shown in Figure 4, the difference current between current Ia and current Ib is calculated. There is also a method that converts the current Ia into an O After the signal is converted to voltage using the p-amp OPa, the AD conversion unit ADCa outputs the digital signal OUT. The function converts to a, and after the current Ib is converted to voltage by the operational amplifier OPb, the AD conversion section A It has a function to convert DCb into a digital signal output OUTb. Output OUTa and output The difference between OUTb and the other can be obtained by performing calculations on OUTb using the calculation unit 195.

[0120] Current Ia is supplied to the inverting input of the operational amplifier OPa, and current Ia is supplied to the non-inverting input of the operational amplifier OPa. A reference voltage Vref is supplied. The output and non-inverting input of the operational amplifier OPa are connected via a resistor Ra. They are electrically connected. Also, current Ib is supplied to the inverting input of the operational amplifier OPb, A reference voltage Vref is supplied to the non-inverting input of the operational amplifier OPb. The force and non-inverting input are electrically connected via resistor Rb.

[0121] The resolution of the AD conversion unit ADCa and the AD conversion unit ADCb in the AD conversion device 190 is Both are 8 bits, and assuming a current value of 1 nA per bit, it exceeds 255 nA. Current Ia and current Ib are such that both output OUTa and output OUTb are (11111111 ) becomes 2. Therefore, for example, if current Ia is 300nA and current Ib is 261nA In total, the output of the AD converter 190 becomes 0.

[0122] Both the AD converter 100 and the AD converter 190 convert the differential current into a digital signal. It has a function to convert. In particular, the AD converter 100 has a function to convert the current values ​​of current Ia and current Ib. Even in large cases, the difference in current between the two can be accurately converted into a digital signal.

[0123] <Example of the configuration of the comparison unit 110> As mentioned above, the comparison unit 110 compares the current value supplied to the input terminal 111a with the input terminal 111 This function compares the current values ​​supplied to terminal b and supplies one of the two potentials to output terminal D. It has a comparison unit 110 which functions as a current comparison type comparator. Figure 5A shows the comparison unit 1 An example of a circuit configuration applicable to 10 is shown.

[0124] The comparison section 110 shown in Figure 5A consists of transistors M11a, M11b, and Transistor M11c, Transistor M11d, Transistor M12a, Transistor M12b, Transistor M12c, Transistor M12d, Transistor M13a, Transistor M 13b, transistor M14a, transistor M14b, transistor M15a, transistor Transistor M15b, Transistor M16a, Transistor M16b, Transistor M17a , and transistor M17b. Also, the comparison section 110 shown in Figure 5A is an inverter It is equipped with a turbocharger INVa and an inverter INVb.

[0125] Furthermore, the comparison unit 110 shown in Figure 5A is equipped with an output terminal DB. The output terminal DB has two The other potential is supplied. That is, when potential H is supplied to output terminal D. In this case, a potential L is supplied to output terminal DB. Also, if a potential L is supplied to output terminal D, A potential of H is supplied to the output terminal DB.

[0126] Output terminals D and DB only need to be present at least one of them. For example, output terminals If DB is not needed, you do not need to provide an output terminal DB. In this case, output terminal DB and inverter INVb do not need to be provided.

[0127] Transistor M11a, Transistor M11b, Transistor M11c, Transistor M 11d, transistor M12a, transistor M12b, transistor M12c, transistor Transistor M12d, transistor M14a, and transistor M14b are p-channel type transistors. It is a transistor. Also, transistor M13a, transistor M13b, transistor M15a, transistor M15b, transistor M16a, transistor M16b, tra Transistors M17a and M17b are n-channel transistors.

[0128] Either the source or drain of transistor M11a is electrically connected to terminal 112. The other end is electrically connected to either the source or drain of transistor M12a. The source or drain of transistor M12a, the other side of the gate of transistor M11a, and The gate of transistor M11b is electrically connected to input terminal 111a. The gate of transistor M12a and the gate of transistor M12b are electrically connected to terminal 113. Connected.

[0129] Either the source or drain of transistor M11b is electrically connected to terminal 112. The other end is electrically connected to either the source or drain of transistor M12b. One of the source or drain of the converter M13a is electrically connected to terminal 112, and the other is connected to terminal 112. This is electrically connected to the other side of the source or drain of transistor M12b.

[0130] The gates of transistor M13a and transistor M13b are connected to terminal 114. It is electrically connected.

[0131] Either the source or drain of transistor M11c is electrically connected to terminal 112. The other end is electrically connected to either the source or drain of transistor M12c. The source or drain of transistor M12c, the other side of the gate of transistor M11c, and The gate of transistor M11d is electrically connected to input terminal 111b. The gate of transistor M12c and the gate of transistor M12d are electrically connected to terminal 113. Connected.

[0132] Either the source or drain of transistor M11d is electrically connected to terminal 112. The other end is electrically connected to either the source or drain of transistor M12d. One of the source or drain of the converter M13b is electrically connected to terminal 112, and the other is connected to terminal 112. This is electrically connected to the other side of the source or drain of transistor M12d.

[0133] Either the source or drain of transistor M14a is connected to the source of transistor M13a. Alternatively, it is electrically connected to the other side of the drain, and the other side is the source or of transistor M15a. It is electrically connected to one of the drains. Source or drain of transistor M15a The other end is electrically connected to terminal 117. The gate and transistor of transistor M14a The gate of transistor M15a is connected to either the source or drain of transistor M16b, The input of inverter INVb is electrically connected. The output of inverter INVb is connected to the output terminal. It is electrically connected to the child DB. The source or drain of transistor M16b is the other. It is electrically connected to terminal 117.

[0134] Either the source or drain of transistor M17b is connected to the source of transistor M14b. Alternatively, one end is electrically connected to the drain, and the other end is electrically connected to terminal 117. The gates of transistor M16b and transistor M17b are connected to terminal 116 and electrical It connects to the target.

[0135] Either the source or drain of transistor M14b is connected to the source of transistor M13b. Alternatively, it is electrically connected to the other side of the drain, and the other side is the source of transistor M15b or It is electrically connected to one of the drains. Source or drain of transistor M15b The other end is electrically connected to terminal 117. The gate and transistor of transistor M14b The gate of transistor M15b is connected to either the source or drain of transistor M16a, It is electrically connected to the input of the inverter INVa. The output of the inverter INVa is connected to the output terminal. It is electrically connected to child D. The other end of the source or drain of transistor M16a is at the end. It is electrically connected to child 117.

[0136] Either the source or drain of transistor M17a is connected to the source of transistor M14a. Alternatively, one end is electrically connected to the drain, and the other end is electrically connected to terminal 117. The gate of transistor M16a and the gate of transistor M17a are connected to terminal 115 and electrical It connects to the target.

[0137] Vdd is supplied to terminal 112, and Vss is supplied to terminal 117. Also, terminal 11 The potential of point 7 may be used as GND.

[0138] Terminal 113 receives the first control signal Sig1, and terminal 114 receives the second control signal Sig2 The signal is supplied, and the third control signal Sig3 is supplied to terminals 115 and 116. Figure 5 B shows the potential change at terminals 113 to 116.

[0139] The comparison unit 110 shown in Figure 5A is configured such that the first control signal Sig1 and the third control signal Sig3 are at potentials. When the voltage is low (L) and the second control signal Sig2 is at a high (H) during the period Tw, current flows to the input terminal 111a. The current Ia and the current Ib flowing through input terminal 111b are compared, and the comparison result is output to the output terminal. Output is sent to terminals D and DB.

[0140] The comparison unit 110 shown in Figure 5A is used when the first to third control signals are in the aforementioned combination. Because it is an operating comparator, it can consume less power than a continuously operating comparator. Furthermore, it can convert the input current into a digital signal without converting it to voltage, thus eliminating the need for electricity. This enables a reduction in power consumption and occupied area. Therefore, the AD converter has reduced power consumption. 100 can be realized. In addition, an AD converter 100 with reduced footprint can be realized.

[0141] Also, in the circuit configuration of the comparison unit 110 shown in FIG. 5A, p-channel transistors may be used for the transistor M13a and the transistor M13b. However, it is preferable to use n-channel transistors for the transistor M13a and the transistor M13b. For example, when Vdd is 3.3V and Vss is 0V, if p-channel transistors are used for the transistor M13a and the transistor M13b, the potential H supplied to the terminal 114 needs to be 3.3V (Vdd), and the potential L needs to be approximately 2.8V. When n-channel transistors are used for the transistor M13a and the transistor M13b, the potential H supplied to the terminal 114 can be 1.2V, and the potential L can be 0V (Vss). Therefore, by using n-channel transistors for the transistor M13a and the transistor M13b, the potential required for circuit operation can be reduced. That is, the power consumption can be reduced.

[0142]

[0143]

[0144] Also, when 2.8V is used for circuit operation, it is necessary to newly provide a power supply. On the other hand, since 1.2V is a potential used as the power supply potential of a general semiconductor device, it is suitable because there is no need to newly provide a power supply.

[0145] <Configuration Example of the DA Conversion Unit 130>

[0146] FIG. 6A is a block diagram showing a configuration example of the DA conversion unit 130. The DA conversion unit 130 has a switch SWW. The first terminal of the switch SWW is electrically connected to the output terminal C, and the second terminal of the switch SWW is electrically connected to the wiring VINIL1. The wiring VINI L1 functions as a wire that provides an initialization potential to the output terminal C, and as an initialization potential This can be GND, Vss, Vdd, etc. Note that the switch SWW is the output terminal. It is in the ON state only when an initialization potential is applied to child C, and in the OFF state at all other times. It shall be assumed that...

[0145] Examples of switches include analog switches, transistors, and other electrical switches. A mechanical switch, such as a MEMS switch, can be used.

[0146] Furthermore, the DA conversion unit 130 shown in Figure 6A has a current mirror circuit CM. The CM circuit has transistors Q1 and Q2. Transistor Q1 The first terminal is electrically connected to terminal Qin and the gate of transistor Q1. The second terminal of transistor Q1 is supplied with Vss or GND. The first terminal of transistor Q2 It is electrically connected to terminal Qout. The second terminal of transistor Q2 is connected to Vss or G ND is supplied. The gate of transistor Q2 is electrically connected to the gate of transistor Q1. Connected.

[0147] Furthermore, the DA conversion unit 130 shown in Figure 6A has multiple current sources CS. Specifically, DA The conversion unit 130 is Kbit (2 K Output the first data value (where K is an integer greater than or equal to 1) as current. It has the function of doing so, and in this case, the DA conversion unit 130 is 2 K -It has one current source CS. Oh, the DA conversion unit 130 outputs information corresponding to the value of the first bit as a current source C It has one S and two current sources CS that output information corresponding to the second bit value as current. There are two current sources CS that output information corresponding to the value of the K-th bit as current. K-1 There are two.

[0148] In FIG. 6A, each current source CS has a terminal T1 and a terminal T2. Each terminal T1 of the current source CS is electrically connected to the terminal Qin of the current mirror circuit CM. Also, the terminal Qout of the current mirror circuit CM is electrically connected to the output terminal C. Also, the terminal T2 of one current source CS is electrically connected to the terminal DW[1], and each of the terminals T2 of the two current sources CS is electrically connected to the terminal DW[2], and each of the terminals T2 of the two current sources CS is electrically connected to the terminal DW[K]. K-1 two current sources CS is electrically connected to the terminal DW[K].

[0149] A digital signal output from the control unit 120 is input to the terminal DW. Specifically, the information of the first bit of the digital signal is input to the terminal DW[1], the information of the second bit is input to the terminal D W[2], and the information of the K-th bit is input to the terminal DW[K].

[0150] The plurality of current sources CS included in the DA conversion unit 130 shown in FIG. 6A each have a function of outputting the same constant current I W ut from the terminal T1. In practice, at the production stage of the arithmetic circuit, errors may occur due to variations in the characteristics of the transistors included in each current source CS. The error of the constant current I output from each of the terminals T1 of the plurality of current sources CS is preferably within 10%, more preferably within 5%, and even more preferably within 1%. In the present embodiment, the plurality of current sources Wu t included in the DA conversion unit 130 ​​Constant current I output from terminal T1 of CS Wut We will explain assuming there is no error.

[0151] Terminals DW[1] to DW[K] receive a constant current I from the electrically connected current source CS. Wut It functions as wiring to transmit control signals for outputting. Specifically, for example, When Vdd is applied to terminal DW[1], terminal DW[1] is electrically connected to The current source CS is a constant current I Wut The current is passed to terminal T1, and Vss is supplied to terminal DW[1]. When this is the case, the current source CS electrically connected to terminal DW[1] is a constant current I W ut It does not output. Also, for example, when Vdd is given to terminal DW[2], terminal The two current sources CS, which are electrically connected to DW[2], total 2I Wut Let this be a constant current. When current flows to terminal T1, and Vss is given to terminal DW[2], terminal DW[2 The current source CS, which is electrically connected to ], has a total of 2I Wut It does not output a constant current. For example, when Vdd is applied to terminal DW[K], the terminal DW[K] is electrically connected Continuing 2 K-1 The current sources CS total 2 K-1 I Wut Set as a constant current at terminal T1 When a current flows through it, and Vss is applied to terminal DW[K], the electrical current flows through terminal DW[K]. The connected current sources CS total 2 K-1 I Wut It does not output a constant current.

[0152] The current flowing from one current source CS electrically connected to terminal DW[1] is the first bit The value corresponds to the current flowed by the two current sources CS, which are electrically connected to terminal DW[2], This corresponds to the value of the second bit and is electrically connected to terminal DW[K]. K-1 individual current sources The current flowing through CS corresponds to the value of the Kth bit. Here, the DA conversion section when K is set to 2. Let's consider 130.

[0153] For example, when the value of the first bit is "1" and the value of the second bit is "0", terminal DW[1] will have V Given dd, terminal DW[2] is given Vss. At this time, the current mirror cycle I is the reference current at terminal Qin of the circuit CM. Wut It plays.

[0154] Also, for example, when the value of the first bit is "0" and the value of the second bit is "1", terminal DW[1 Vss is given to terminal DW[2], and Vdd is given to terminal DW[2]. At this time, the current 2I is the reference current applied to terminal Qin of the Miller circuit CM. Wut It plays.

[0155] Also, for example, when the value of the first bit is "1" and the value of the second bit is "1", terminal DW[1 Vdd is applied to terminals ] and DW[2]. At this time, the current mirror circuit CM 3I is the reference current connected to terminal Qin. Wut It plays.

[0156] Furthermore, a current corresponding to the reference current flows through terminal Qout. Therefore, a current corresponding to the reference current also flows through output terminal C. Current flows according to the current. Transistor characteristics of transistors Q1 and Q2. If the values ​​are the same, the current flowing through terminal Qin and the current flowing through terminal Qout will be equal. Therefore, the current flowing through terminal Qin and the current flowing through output terminal C are equal.

[0157] Also, for example, when the value of the 1st bit is "0" and the value of the 2nd bit is "0", terminal DW[1 Vss is applied to terminal DW "2" and ]. In this case, current flows through terminal Qin. No. Therefore, no current flows to the output terminal.

[0158] Figure 6A shows an example of the configuration of the DA conversion unit 130 when K is an integer of 3 or greater. However, if K is 1, it is electrically connected to terminals DW[2] to DW[K] in Figure 6A. The configuration should be such that the current source CS is not provided. Similarly, if K is 2, see Figure 6. Current source C is electrically connected to terminals DW[3] (not shown) to DW[K] of A. The solution is to create a configuration that does not include S.

[0159] Next, we will describe a specific example configuration of the current source CS.

[0160] The current source CS1 shown in Figure 7A is applicable to the current source CS included in the DA conversion unit 130 in Figure 6A. The circuit is such that the current source CS1 consists of transistor Tr1 and transistor Tr2. To possess.

[0161] The first terminal of transistor Tr1 is electrically connected to the wiring VDDL, and transistor Tr The second terminal of 1 is the gate of transistor Tr1, the back gate of transistor Tr1, and It is electrically connected to the first terminal of transistor Tr2. Terminal 2 is electrically connected to terminal T1, and the gate of transistor Tr2 is electrically connected to terminal T2. They are electrically connected. Also, terminal T2 is electrically connected to terminal DW. W is one of terminals DW[1] through DW[K] in Figure 6A.

[0162] Wiring VDDL functions as wiring that provides a constant voltage. This constant voltage is, for example, V It can be written as dd.

[0163] When the constant voltage supplied by the wiring VDDL is Vdd, the first terminal of transistor Tr1 has V The input is dd. Also, the potential of the second terminal of transistor Tr1 is lower than Vdd. Let it be at this position. At this time, the first terminal of transistor Tr1 functions as the drain, and the transistor The second terminal of Tr1 functions as a source.

[0164] Furthermore, the gate of transistor Tr1 and the second terminal of transistor Tr1 are electrically connected. Because it is connected, the gate-source voltage of transistor Tr1 becomes 0V. If the threshold voltage of transistor Tr1 is within the appropriate range, then transistor Tr1 A current in the subthreshold region (drain current) flows between the first and second terminals. Furthermore, the current must be within a range that increases exponentially with respect to the gate-source voltage. This is more preferable. In other words, transistor Tr1 carries current in the subthreshold region. It functions as a current source.

[0165] In this specification and elsewhere, the subthreshold region refers to the gate voltage (V) of the transistor. g) In the graph showing the drain current (Id) characteristics, the absolute value of the gate voltage is the threshold. This refers to the region where the voltage is smaller than the absolute value of the voltage. Alternatively, the subthreshold region is the gradient. This deviates from the multi-channel approximation (a model that only considers drift current) due to carrier diffusion. This refers to the region in which a certain current flows. Alternatively, the subthreshold region is the region in which, in response to an increase in gate voltage, This refers to the region in which the drain current increases exponentially. Or, the subthreshold region. This includes areas that can be considered to be the domains of each of the above-mentioned explanations.

[0166] Furthermore, the drain current when a transistor operates in the subthreshold region is defined as the subthreshold. This is called the subthreshold current. The subthreshold current is independent of the drain voltage and the gate voltage. It increases exponentially with respect to . In circuit operation using subthreshold current, the drain This reduces the impact of variations in voltage.

[0167] Transistor Tr2 functions as a switching element. By the way, transistor Tr If the potential of the first terminal of 2 is higher than the potential of the second terminal of transistor Tr2, the transistor The first terminal of transistor Tr2 functions as the drain, and the second terminal of transistor Tr2 is the source. It functions as follows. Also, the back gate of transistor Tr2 and the second of transistor Tr2 Since the two terminals are electrically connected, the back gate-source voltage is 0V. Therefore, if the threshold voltage of transistor Tr2 is within an appropriate range, transistor Tr When Vdd is input to the gate of transistor 2, transistor Tr2 will be turned ON. When Vss is input to the gate of transistor Tr2, transistor Tr2 is turned off. The state is assumed to be such that, when transistor Tr2 is in the ON state, the above-mentioned Current in the threshold region flows from the second terminal of transistor Tr1 to terminal T1, When transistor Tr2 is in the off state, current flows from the second terminal of transistor Tr1 to terminal T1. It won't flow.

[0168] Furthermore, the circuit applicable to the current source CS included in the DA conversion unit 130 in Figure 6A is the same as the circuit in Figure 7A. The current source is not limited to CS1. For example, the current source CS1 is the backgain of transistor Tr2. The configuration is such that the second terminal of transistor Tr2 is electrically connected to the The back gate of the Tr2 transistor may be configured to be electrically connected to a separate wiring harness. An example of such a configuration is shown in Figure 7B. The current source CS2 shown in Figure 7B is transistor Tr2 The back gate is electrically connected to the wiring VTHL. Current source CS 2. When the wiring VTHL is electrically connected to an external circuit, etc., via the wiring VTHL The external circuit applies the predetermined potential to the back gate of transistor Tr2. This allows us to vary the threshold voltage of transistor Tr2. In particular, by increasing the threshold voltage of transistor Tr2, The off-current can be reduced.

[0169] The current source CS1 is connected to the back gate of transistor Tr1 and the second terminal of transistor Tr1. The configuration is such that the back gate and the torso of transistor Tr1 are electrically connected. The voltage between the second terminal of transistor Tr1 and the other terminal may be maintained by capacitance. An example configuration is shown in Figure 7C. The current source CS3 shown in Figure 7C is a transistor Tr1, In addition to transistor Tr2, it also has transistor Tr3 and capacitor C6.

[0170] The current source CS3 is connected to the second terminal of transistor Tr1 and the back gate of transistor Tr1. The points of electrical connection via capacitance C6 and the back gate and of transistor Tr1 The difference between transistor Tr3 and current source CS1 is that the first terminal of transistor Tr3 is electrically connected.

[0171] Furthermore, the second terminal of transistor Tr3 is electrically connected to the wiring VTL, and transistor T The current source CS3, whose gate r3 is electrically connected to the wiring VWL, has Vd connected to the wiring VWL. By giving d and turning on transistor Tr3, the wiring VTL and the transistor It is possible to create a conductive state between the back gate of Tr1. Therefore, the wiring VTL or A predetermined potential can be input to the back gate of transistor Tr1. Also, transistor T By turning off r3, capacitance C6 is used to connect to the second terminal of transistor Tr1. The voltage between the back gate of transistor Tr1 can be maintained, that is, via the wiring VTL. By controlling the voltage applied to the back gate of transistor Tr1, the transistor The threshold voltage of transistor Tr1 can be varied, and transistor Tr3 and capacitor C6 This allows the threshold voltage of transistor Tr1 to be fixed. Also, the potential of the wiring VTL By controlling this, the current value flowing to terminal T1 per bit can be controlled.

[0172] Furthermore, a circuit that can be applied to the current source CS included in the DA conversion unit 130 in Figure 6A is shown in Figure 7. The current source CS4 shown in D may also be used. The current source CS4 is the same as the current source CS3 in Figure 7C. The back gate of transistor Tr2 is connected to the second terminal of transistor Tr2, not to the wiring VTH. It is configured to be electrically connected to L. In other words, current source CS4 is the same as current source CS in Figure 7B. Similar to 2, control the potential applied to the back gate of transistor Tr2 via the wiring VTHL. By controlling this, the threshold voltage of transistor Tr2 can be varied.

[0173] In the current source CS4, a large current flows between the first and second terminals of transistor Tr1. In this case, in order to allow the current to flow from terminal T1 to the outside of the current source CS4, the transistor Tr The on-current of 2 needs to be increased. In this case, the current source CS4 is connected to the wiring VTHL via Vd By giving d, the threshold voltage of transistor Tr2 is lowered, and transistor Tr2 turns ON. By increasing the current, the flow between the first and second terminals of transistor Tr1 increases A large current can be supplied from terminal T1 to the outside of the current source CS4.

[0174] Also, if you want to reduce the current flowing between the first and second terminals of transistor Tr1 Alternatively, you can reduce the potential supplied to the VTHL wiring. It may be supplied.

[0175] Furthermore, a circuit that can be applied to the current source CS included in the DA conversion unit 130 in Figure 6A is shown in Figure 7. The current source CS5 shown in E may also be used. Current source CS5 is a modified version of current source CS1, and The gate of transistor Tr1 is connected to the wiring VGL and electrical connections, not to the second terminal of transistor Tr1. The difference from the current source CS1 is that it is connected to the VGL wiring, for example, transistor Tr1 A potential is supplied that operates in the subthreshold region. This controls the potential of the wiring VGL. This allows us to control the current flowing through terminal T1 for each bit.

[0176] The current source CS included in the DA conversion unit 130 in Figure 6A is the current shown in Figures 7A to 7E. By applying power source CS1 to current source CS5, the DA conversion unit 130 performs the K-bit analysis. It can output a current corresponding to a single data point.

[0177] Alternatively, the circuit shown in Figure 6B may be used as the DA conversion unit 130. DA conversion in Figure 6B Section 130 has a current source CS1 as shown in Figure 7A connected to each of terminals DW[1] to DW[K]. They are connected one by one.

[0178] Also, if the channel lengths of transistors Tr1[1] to Tr1[K] are the same The channel width of transistor Tr1[1] is w[1], and the channel width of transistor Tr1[2] is w[1]. When the channel width is w[2] and the channel width of transistor Tr1[K] is w[K], The ratio of each channel width is w[1]:w[2]:w[K]=1:2:2 K-1 And so Yes. The current is flowing between the source and drain of a transistor operating in the subthreshold region. Since the flow is proportional to the channel width, the DA conversion unit 130 shown in Figure 6B is the same as the DA conversion in Figure 6A. Similar to section 130, it can output a current corresponding to the first K-bit data.

[0179] Note that transistor Tr1 (transistor Tr1[1] to transistor Tr1[K]) (including), transistor Tr2 (transistor Tr2[1] to transistor Tr2[K] (including), and it is preferable that transistor Tr3 be an OS transistor.

[0180] OS transistors have a gate voltage that is less than the transistor's threshold voltage, resulting in a 1x1 0 -20 Less than A, 1 x 10 -22 Less than A, or 1 × 10 -24 Channels less than A It is possible to pass an extremely small current as the drain current per 1 μm of width. When the gate voltage of a transistor is equal to the transistor's threshold voltage, the voltage is 1.0 × 10 -8 A Below, 1.0 × 10 -12 A or less, or 1.0 × 10 -15Channels below A It can pass a drain current per 1 μm of width. For example, an OS transistor can sub In the threshold region, the drain current per 1 μm of channel width is 1 × 10⁻¹⁶. -24 A or higher 1.0 x 10 -8 It can be flowed within the range of A or less.

[0181] OS transistors operate in the subthreshold region with a large gate voltage range. It can pass subthreshold currents of different magnitudes. In other words, an OS transistor is This allows for a wider range of gate voltages operating in the subthreshold region. Specifically, when the threshold voltage of the OS transistor is Vth, the subthreshold region So, (Vth-1.0V) or above Vth, or (Vth-0.5V) or above Vth. The circuit can be operated using gate voltages within the following voltage range.

[0182] On the other hand, Si transistors have a large off-current and operate in the subthreshold region. The voltage range is narrow. When using subthreshold current, the OS transistor is... It can operate in a wider gate voltage range than Si transistors.

[0183] Therefore, as a transistor to operate in the subthreshold region, an OS transistor is used. It is preferable to use it. However, depending on the purpose or application, in the subthreshold region Other transistors besides OS transistors may be used as the transistors to operate the circuit. OS transistors may be used in combination with other types of transistors. .

[0184] A modified version of the DA conversion unit 130 shown in Figure 6A is shown in Figure 8A. DA conversion unit 13 The difference between unit 0 and the DA conversion unit 130 shown in Figure 6A is that unit 0 does not have a current mirror circuit CM. .

[0185] Example configuration of current source CS6 that can be used in the current source CS of the DA conversion unit 130 shown in Figure 8A. This is shown in Figure 8B.

[0186] The current source CS6 shown in Figure 8B has transistor Tr1 and transistor Tr2. The first terminal of transistor Tr1 is supplied with either Vss or GND. The second terminal of Tr1 is electrically connected to the first terminal of transistor Tr2. The second terminal of Tr2 is electrically connected to terminal T1.

[0187] The gate of transistor Tr1 is electrically connected to wiring VGL. Wiring VGL is, for example, Then, a potential is supplied that allows transistor Tr1 to operate in the subthreshold region. Wiring V By controlling the potential of GL, the current value flowing to terminal T1 per bit can be controlled.

[0188] The gate of transistor Tr2 is electrically connected to terminal T2. The back gate of transistor Tr2 is the first terminal of transistor Tr1. It is electrically connected to the child.

[0189] Figure 8C shows an example configuration of current source CS7, which is a modified version of current source CS6. In current source CS7, The gate and back gate of transistor Tr1 are electrically connected, and transistor Tr2 The gate and back gate are electrically connected. This allows you to increase the on-current of the transistor.

[0190] Furthermore, as the current source CS of the DA conversion unit 130 shown in Figure 8A, the current source CS8 shown in Figure 8D is used. It can be used. The current source CS8 is a p-channel type transistor connected to transistor Tr1. This system uses an n-channel transistor for transistor Tr2.

[0191] In the current source CS8, the first terminal of transistor Tr1 is supplied with either Vss or GND. The second terminal of transistor Tr1 is electrically connected to the first terminal of transistor Tr2. The second terminal of transistor Tr2 is electrically connected to terminal T1. The gate and back gate of transistor Tr1 are electrically connected to the second terminal of transistor Tr1. The back gate of transistor Tr2 is electrically connected to the first terminal of transistor Tr2. It continues. Note that the current source CS8 has a different direction of current flowing through terminal T1, but the current It can operate in the same way as Gen CS1.

[0192] Furthermore, the current source CS of the DA conversion unit 130 shown in Figure 8A is the current source CS9 shown in Figure 8E. You may use it.

[0193] The current source CS9 is connected to the second terminal of transistor Tr1 and the back gate of transistor Tr1. The points of electrical connection via capacitance C6 and the back gate and of transistor Tr1 The difference between the transistor Tr3 and the current source CS8 is that the first terminal of the transistor Tr3 is electrically connected.

[0194] Furthermore, the current source CS9 has the second terminal of transistor Tr3 electrically connected to the wiring VTL. The gate of transistor Tr3 is electrically connected to the wiring VWL. Current source CS9 is By applying Vdd to the wiring VWL and turning on transistor Tr3, the wiring It is possible to create a conductive state between the line VTL and the back gate of transistor Tr1. So, via transistor Tr3, the wiring from VTL to the back gate of transistor Tr1 A predetermined potential can be input to it. Also, by turning off transistor Tr3, Capacitor C6 connects the second terminal of transistor Tr1 to the back gate of transistor Tr1. The voltage between these two points can be maintained. It is supplied to the back gate of transistor Tr1 via the wiring VTL. By controlling the voltage, the threshold voltage of transistor Tr1 can be varied. And, through transistor Tr3 and capacitor C6, the threshold voltage of transistor Tr1 is controlled. The pressure can be fixed.

[0195] Current source CS9 operates similarly to current source CS3, although the direction of the current flowing through terminal T1 is different. It can be made.

[0196] Furthermore, the current source CS of the DA conversion unit 130 shown in Figure 8A is the current source CS10 shown in Figure 8F. You may use the following. Current source CS10 is a modified version of current source CS8, and transistor Tr1 The point is that the gate is electrically connected to the wiring VGL, rather than to the second terminal of transistor Tr1. Different from the current source CS8. For example, in the wiring VGL, transistor Tr1 is subthreshold A potential is supplied that operates in the dot region. By controlling the potential of the wiring VGL, per bit The current value flowing through terminal T1 can be controlled.

[0197] Furthermore, current sources CS8 to CS10 are like current sources CS2 and CS4, The back gate of transistor Tr2 is connected to the wiring V, not to the first terminal of transistor Tr2. It may be electrically connected to THL. Backgear of transistor Tr2 via wiring VTHL By controlling the potential applied to the terminal, the threshold voltage of transistor Tr2 can be varied. It can be done.

[0198] Furthermore, the DA conversion unit 130 shown in Figure 8A has the same configuration as the DA conversion unit 130 shown in Figure 6B. You may do so.

[0199] This embodiment can be appropriately combined with other embodiments shown in this specification and elsewhere.

[0200] (Embodiment 2) A semiconductor device according to one aspect of the present invention is, for example, a device that performs calculations for a neural network. It can be used in circuits. In this embodiment, the neural network is used to perform calculations. Let's explain the arithmetic circuit.

[0201] <Hierarchical Neural Network> First, let's explain hierarchical neural networks. A workpiece might consist of, for example, one input layer, one or more intermediate layers (hidden layers), and one output layer. It has layers and is composed of a total of 3 or more layers. Figure 9A shows a hierarchical neural network. The neural network 300 is an example of this, and the neural network 300 is the first It has layers up to the Rth layer (where R can be an integer greater than or equal to 4). In particular, The first layer corresponds to the input layer, the Rth layer corresponds to the output layer, and the other layers correspond to the hidden layers. Note that Figure 9A shows the (k-1)th layer and the kth layer (where k is 3 or greater, R-1) as intermediate layers. The following integers are used.) are shown in the diagram, and other intermediate layers are omitted from the diagram. .

[0202] Each layer of the neural network 300 has one or more neurons. (See Figure 9A) In this layer, the first layer is neuron N1 (1) Neuron N p (1) (p is an integer greater than or equal to 1.) ) has, and layer (k-1) has neurons N1 (k-1) Neuron N m (k-1) ( m is an integer greater than or equal to 1. The k-th layer has neurons N1 (k) Neuron N n (k) (n is an integer greater than or equal to 1.) The R layer has neurons N1 (R) Neuron N q (R ) (q is an integer greater than or equal to 1.)

[0203] Note that Figure 9A shows neuron N1 (1) , Neuron N p (1) , neuron N1 (k -1) , Neuron N m (k-1) , neuron N1 (k) , Neuron N n (k) , Ni URON N1 (R) , Neuron N q (R) In addition, the (k-1) layer neurons N i (k-1) (i is an integer between 1 and m, inclusive.) Neuron N in layer k j (k) (j is 1 or greater) Integers less than or equal to n are also shown in the diagram, but other neurons are not.

[0204] Next, the transmission of signals from neurons in the previous layer to neurons in the next layer, and each of the neurons Describe the signals input and output in Ron. In this description, focus on the neuron N in the k-th layer. neuron j (k) is focused on.

[0205] Figure 9B shows the neuron N in the k-th layer j (k) and the signal input to the neuron N j (k) and the signal output from the neuron N neuron j (k) to.

[0206] Specifically, the output signals z1 to z of each of the neurons N1 to N in the (k - 1)-th layer (k-1) to neuron N m (k-1) are output towards the neuron N (k-1) to z m (k-1) neuron j (k ) and the neuron N j (k) generates z according to z1 to z (k-1) to z m (k-1) and outputs z as an output signal to each neuron in the (k + 1)-th layer j (k) to z j (k) (not shown). (Figure not shown.)

[0207] The signal input from the neuron in the previous layer to the neuron in the next layer is determined by the connection strength of the synapses connecting those neurons (hereinafter referred to as the weight coefficient). In the neural network 300, the signal output from the neuron in the previous layer is multiplied by the corresponding weight coefficient and input to the neuron in the next layer. Let i be 1 or more and m or less The signal output from the neuron in the previous layer is multiplied by the corresponding weight coefficient and input to the neuron in the next layer. Let i be 1 or more and m or less As the following integer, neuron N in the (k - 1)-th layer i (k-1) and neuron N in the k-th layer j (k) when the synaptic weight coefficient between them is w i (k-1) j (k) the signal input to neuron N in the k-th layer can be expressed by Equation (1.1). j (k) That is, when signals are transmitted from neuron N1 in the (k - 1)-th layer

[0208]

Equation

[0209] to neuron N in the k-th layer (k-1) to neuron N m (k-1) respectively, for signals z1 to z j (k) corresponding weights (w1 ( k-1) to w m (k-1) ) are multiplied. And for neuron N in the k-th layer (k-1) j (k) to w m (k-1) j (k) ·z1 j (k) to w (k-1) j (k) ·z (k-1) to w m (k-1) j (k) ·z m (k-1) is input. At this time, the signal input to neuron N in the k-th layer j (k) ​ The sum u j (k) This is given by equation (1.2).

[0210]

number

[0211] Also, the weight coefficient w1 (k-1) j (k) Or maybe lol m (k-1) j (k) And the belief of neurons No. z1 (k-1) ~z m (k-1) The result of the sum of products of and is biased. It is also acceptable to rewrite equation (1.2) as equation (1.3) when the bias is b. It is possible.

[0212]

number

[0213] Neuron N j (k) , u j (k) Depending on the output signal z j (k) This generates the following. , Neuron N j (k) Output signal z from j (k) We define it by the following equation (1.4).

[0214]

number

[0215] function f(u j (k) ) is an activation function in a hierarchical neural network, Step functions, linear ramp functions, sigmoid functions, etc., can be used. The transformation function may be the same for all neurons, or it may be different for all neurons. Therefore, the activation function of neurons may be the same or different in each layer.

[0216] By the way, the signals output by neurons in each layer, the weight coefficient w, and the bias b are analogous. It can be a metric value, a discrete value with two or more values, or a digital value. A digital value must be 1 bit or more. For example, if the signals output by neurons in each layer are analog values, the activation function would be... Therefore, you can use functions such as the linear ramp function and the sigmoid function. Also, the neurons in each layer If the signal being transmitted is a 1-bit (binary) digital value, for example, the output can be either -1 or 1. A step function that converts to either one of the following, or a step function that converts to either 0 or 1. You can use it.

[0217] Furthermore, if the signals output by neurons in each layer are trivalued, the activation function is, for example, output A step function that converts to -1, 0, or 1, or 0, 1, or 2 A step function or similar can be used to convert to one of the following. Also, the neurons in each layer output If the signal is 5-valued, the activation function can, for example, output -2, -1, 0, 1, or You may also use a step function or similar to convert to either of the two values.

[0218] Furthermore, the signals output by neurons in each layer, the weight coefficient w, or the bias b are at least One way to reduce the size of the circuit and lower power consumption is to use digital values. This enables things like increasing processing speed. The signal output by the unit, the weighting coefficient w, or the bias b are all analog values. By doing so, the accuracy of calculations can be improved.

[0219] The neural network 300, when an input signal is input to the first layer (input layer) Then, in each layer from the first layer (input layer) to the last layer (output layer), the input is processed sequentially from the previous layer. Based on the signal obtained, equations (1.1), (1.2) (or (1.3)), and (1.4) The system generates an output signal using this method and outputs that output signal to the next layer. The last layer (output The signal output from the power layer is calculated by neural network 300. It corresponds to.

[0220] <Example of arithmetic circuit configuration> Here, in the neural network 300 described above, equation (1.2) (or equation (1 Examples of arithmetic circuits capable of performing the operations in equation (3)) and equation (1.4) are described below. Furthermore, in the said calculation circuit, as an example, the synapses of neural network 300 The weight coefficients of the circuit can be binary (a combination of "-1" and "+1", or "0" and "+1"). Combinations, etc.), 3 values ​​(combinations of "-1", "0", and "1", etc.), or 4 values ​​or less. The above is a multi-valued value (in the case of a 5-valued value, a combination of "-2", "-1", "0", "1", "2", etc.) Assuming the neuron's activation function is binary (a combination of "-1", "+1", or "0") , combinations such as "+1", 3 values ​​(combinations such as "-1", "0", and "1"), Outputs multiple values ​​of four or more (for example, a combination of "0", "1", "2", and "3" in the case of four values). Let this be a function that does the following. Note that the weight coefficients of the synaptic circuits of neural network 300, and Furthermore, the value of the signal input from the neuron in the previous layer to the neuron in the next layer is limited to a digital value. It is not possible to use analog values ​​for at least one of them.

[0221] The calculation circuit 310 shown in Figure 10A is, as an example, an array unit ALP, a circuit ILD, and a circuit This is a semiconductor device having a WLD, a circuit XLD, and a circuit AFP. The arithmetic circuit 310 is Neurons N1 in layer k in Figures 9A and 9B (k) Neuron N n (k) Enter The signal z1 (k-1) ~z m (k-1) Process, neuron N1 (k) ~ Neuron N n (k) The signal z1 is output from each of them. (k) ~z n (k) Generate It is a circuit.

[0222] Furthermore, the entirety of the arithmetic circuit 310, or a part thereof, is connected to a neural network. It may be used for purposes other than AI, such as graphics calculations or scientific calculations. In this case, when performing a sum-of-accumulate operation or a matrix operation, the entire arithmetic circuit 310, It is also possible to use a part of it to perform processing. In other words, not only calculations for AI, but also general calculations. For calculations, the entirety or a part of the arithmetic circuit 310 may be used.

[0223] Circuit ILD is, for example, a wiring IL[1] through wiring IL[n] and wiring ILB[1] It is electrically connected to wiring ILB[n]. Circuit WLD is, for example, wiring WLS [1] or wiring WLS[m] is electrically connected. Circuit XLD is, for example, connected to wiring X It is electrically connected to LS[1] or wiring XLS[m]. Circuit AFP is, for example, , wiring OL[1] to wiring OL[n], wiring OLB[1] to wiring OLB[n], and They are electrically connected.

[0224] <<Array Unit ALP>> The arithmetic circuit 310 shown in Figure 10A has an array ALP arranged in a matrix of m × n units. It has a circuit MP. Note that in Figure 10A, row i, column j (where i is between 1 and m). The circuit MP located at (i) is an integer such that j is an integer between 1 and n (inclusive). It is written as ,j]. However, in Figure 10A, circuit MP[1,1], circuit MP[m,1] Only circuits MP[i,j], MP[1,n], and MP[m,n] are shown in the diagram. The other circuits (MPs) are not shown in the diagram.

[0225] Circuit MP[i,j] is, for example, a combination of wiring IL[j], wiring ILB[j], and wiring WL. S[i], wiring XLS[i], wiring OL[j], and wiring OLB[j] are electrically connected. It is connected.

[0226] Circuit MP[i,j] is, for example, a neuron N i (k-1) and neuron N j (k) It has the function of holding the weight coefficient (also called the first data) between the two. Specifically, the circuit MP[i,j] is a weighting coefficient input from wiring IL[j] and wiring ILB[j]. It stores the corresponding information (e.g., potential, resistance, current, etc.). Also, the circuit MP[i, j] is neuron N i (k-1) The signal z is the signal output from i (k-1) (Day 2) It also has the function of outputting the product of (also called "ta") and the first data. A concrete example is a circuit. MP[i,j] receives the second data input from wiring XLS[i], and the first data and The current corresponding to the product with the second data is output to wiring OL[j] and wiring OLB[j]. Oh, Figure 10A shows an example where wiring IL[j] and wiring ILB[j] are arranged. As shown, one aspect of the present invention is not limited thereto. Wiring IL[j] and wiring ILB[ Only one of the two options [j] may be present.

[0227] <<Circuit ILD>> Circuit ILD is, for example, a wiring IL[1] through wiring IL[n] and wiring ILB[1] To wiring ILB[n], and via, each of the circuits MP[1,1] to MP[m,n] In contrast, the weight coefficient is the first data w1 (k-1) 1 (k) Or first data w m (k -1) n (k) A function to input corresponding information (e.g., electric potential, resistance, current value, etc.) It has. As a specific example, circuit ILD has a weighting coefficient for circuit MP[i,j] A certain first data w i (k-1) j (k) Corresponding information (e.g., electric potential, resistance value, or The current value and other parameters are supplied by wiring IL[j] and wiring ILB[j].

[0228] <<Circuit XLD>> Circuit XLD is, for example, connected to circuit MP via wiring XLS[1] to wiring XLS[m]. For each of [1,1] or circuit MP[m,n], neuron N1 (k-1) ~ Neuron N m (k) The second data z1 output from (k-1) or the second data z m (k -1) It has the function of supplying. Specifically, circuit XLD has the function of supplying circuits MP[i,1] to For a pathway MP[i,n], neuron N i (k-1) The second data z output from i ( k-1) The corresponding information (e.g., potential, current value, etc.) is provided via the wiring XLS[i]. To give.

[0229] <<Circuit WLD>> Circuit WLD is, for example, a source of information corresponding to the first data input from circuit ILD (for example). It has a function to select the circuit MP to which values ​​(potential, resistance, current, etc.) will be written. For example, in the i-th row of the array ALP, the circuits MP[i,1] to MP[i,n] When writing information (for example, potential, resistance, current, etc.), the WLD circuit, for example, The writing switching elements included in circuit MP[i,1] to circuit MP[i,n] A signal is supplied to the wiring WLS[i] to turn it on or off, except for row i. A potential that turns off the writing switching element included in the circuit MP is supplied to the wiring WLS. It is sufficient to supply it. Note that the example shown is for the case where wiring WLS[i] is installed, but this invention One embodiment is not limited to this. In addition to the wiring WLS[i], for example, the wiring WLS[i] A separate wiring may be provided to transmit an inverted signal of the input signal.

[0230] <<Circuit AFP>> Circuit AFP may include, for example, circuits ACTF[1] to ACTF[n]. For example, the ACTF[j] is a combination of the OL[j] and OLB[j] wirings. It is electrically connected to the following. Circuit ACTF[j] is, for example, connected to wiring OL[j]. Depending on the information input from the wiring OLB[j] (e.g., potential, current value, etc.) It generates a signal. This signal is transmitted to neuron N. j (k) The signal z output from j (k) ni For example, circuits ACTF[1] to ACTF[n] transmit analog signals to digital It may also have the function of converting to a signal. Therefore, circuit ACTF[1] to circuit ACT The AD converter 100 can be used for F[n].

[0231] Furthermore, circuits ACTF[1] through ACTF[n] amplify and output analog signals. It may also have a function, namely a function to convert the output impedance. Alternatively, the circuit ACT F[1] or the circuit ACTF[n] may have the function of converting current or charge into voltage. Alternatively, circuits ACTF[1] through ACTF[n] are electrically connected to each other. The system may also include a function to initialize the potentials of the wiring OL and wiring OLB.

[0232] <<Circuit MP>> Figure 10B shows an example of the configuration of circuit MP[i,j]. Circuit MP[i,j] is connected to circuit MC, Circuit MCr and circuit MCr are provided in circuit MP, with weight coefficients and This is a circuit that calculates the product of the input signals (calculated values) of a neuron. Circuit MC is a circuit that calculates the product of circuit MCr and It can have a similar configuration or a configuration different from the circuit MCr. Therefore, the circuit MCr The symbol "r" is added to distinguish it from circuit MC. Also, it is included in circuit MCr. Furthermore, the designation "r" is also attached to the circuit elements described later.

[0233] The circuit MC has a retaining part HC, and the circuit MCr has a retaining part HCr. The retaining part HC, The HCr and the holding part are devices that hold information (for example, potential, resistance, current, etc.). It has the ability. Furthermore, the first data w set in circuit MP[i,j] i (k-1) j (k) This is determined according to the information held in the holding part HC and the holding part HCr, respectively. Therefore, the retaining part HC and the retaining part HCr are each in the first data w i (k-1) j (k) to The wiring IL[j] and wiring ILB[j] that supply the corresponding information are electrically connected. ru.

[0234] In Figure 10B, circuit MP[i,j] has electrical connections to wiring VE[j] and wiring VEr[j]. It is connected to the wiring VE[j] and VEr[j] which supply constant voltage. It functions in this way. Also, wiring VE[j] discharges current from wiring OL via circuit MC. It also functions as a wiring. In addition, wiring VEr[j] can be connected to wiring OLB via circuit MCr. It also functions as wiring to discharge the current.

[0235] The wiring WL[i] shown in Figure 10B corresponds to the wiring WLS[i] in Figure 10A. The wire WL[i] is electrically connected to the retaining part HC and the retaining part HCr, respectively. The first data w is included in the holding part HC and holding part HCr in circuit MP[i,j] i (k-1 ) j (k) When writing information corresponding to the wiring W, By supplying a predetermined potential to L[i], the connection between the wiring IL[j] and the retaining part HC is established. The circuit is made conductive, and the wiring ILB[j] and the retaining part HCr are made conductive. The first data w is assigned to each of the lines IL[j] and ILB[j]. i (k-1) j (k) in response By supplying a certain potential, the holding part HC and the holding part HCr are each supplied with that potential. You can input things like this. Then, supply a predetermined potential to wiring WL[i] and wiring I The connection between L[j] and the retaining part HC is made non-conductive, and the wiring ILB[j] and the retaining part HCr The space between them is made non-conductive. Then, the first day is applied to each of the retaining part HC and retaining part HCr. Ta lol i (k-1) j (k) The appropriate voltage and other parameters are maintained.

[0236] For example, the first data w i (k-1) j (k) The value is one of the three values: "-1", "0", or "1". Let's consider the case where we take the first data w. i (k-1) j (k) If it is "1", here is an example: Then, a current corresponding to "1" flows from wiring OL[j] through circuit MC to wiring VE[j]. Thus, a predetermined potential is maintained in the holding part HC, and the circuit MCr is connected to the wiring OLB[j]. To prevent current from flowing through the wiring VEr[j], the holding part HCr maintains a potential V0. Also, the first data w i(k-1) j (k) If it is "-1", as an example, To prevent current from flowing from line OL[j] through circuit MC to wiring VE[j], the holding part HC The potential V0 is maintained, and the wiring VEr[j] is transmitted from the wiring OLB[j] through the circuit MCr. A predetermined potential is maintained in the holding part HCr so that a current corresponding to "-1" flows through ]. And then, the first data w i (k-1) j (k) If it is "0", as an example, wiring OL To prevent current from flowing from [j] through the circuit MC to the wiring VE[j], the holding part HC is at a potential. V0 is maintained, and current flows from wiring OLB[j] to wiring VEr[j] via circuit MC. The potential V0 is maintained in the holding part HCr to prevent flow. Note that the potential V0 is, for example, Vs It can be set to s.

[0237] As another example, consider the first data w i (k-1) j (k) This is an analog value, specifically, “ Let's consider the cases where it takes a negative analog value, "0", or a positive analog value. Day 1 Ta lol i (k-1) j (k) If it is a "positive analog value", then from wiring OL[j] to circuit M Through C, an analog current corresponding to a "positive analog value" flows through the wiring VE[j]. A predetermined potential is maintained in the holding part HC, and the wiring OLB[j] is distributed via the circuit MCr. The potential V0 is maintained in the holding part HCr so that no current flows through the line VEr[j]. , 1st data w i (k-1) j (k)If it is a “negative analog value”, wiring OL[j] To prevent current from flowing from the circuit MC to the wiring VE[j], the holding part HC has a potential V0 The negative A is maintained, and the negative A is transmitted from wiring OLB[j] to wiring VEr[j] via circuit MCr. A predetermined potential is maintained in the holding part HCr so that an analog current corresponding to the "analog value" flows. And the first data w i (k-1) j (k) If it is "0", then wiring OL[j] To prevent current from flowing from the circuit MC to the wiring VE[j], the holding part HC has a potential V0. It is held, and no current flows from wiring OLB[j] to wiring VEr[j] via circuit MC. In this manner, the potential V0 is maintained in the holding part HCr.

[0238] Furthermore, the circuit MC transmits currents, etc., according to the information held in the holding part HC to the wiring OL[j]. Alternatively, it has the function of outputting to one side of the wiring OLB[j], and the circuit MCr is held in the holding part HCr. The system outputs current, etc., corresponding to the information received, to the other side of wiring OL[j] or wiring OLB[j]. It has the function of holding the first potential in the holding part HC, and the circuit MC is wired. A current with a first current value is to flow from OL[j] or wiring OLB[j] to wiring VE. When the second potential is held in the holding part HC, the circuit MC is either wiring OL[j] or wiring O A current with a second current value is passed from LB[j] to wiring VE. Similarly, the holding part HCr If the first potential is maintained, circuit MCr is wiring OL[j] or wiring OLB[j] A current with a first current value is passed through the wiring VEr, and a second potential is maintained in the holding part HCr. If this is the case, the circuit MCr is the first to run from wiring OL[j] or wiring OLB[j] to wiring VE. The system is designed to supply current with two current values. The magnitudes of the first and second current values ​​are as follows: Well, the first data w i (k-1) j (k) It is determined by the value of . Therefore, the first current value The first current value may be greater than or less than the second current value. In some cases, one of the second current values ​​is zero current, meaning the current value is 0. Alternatively, the first current value The direction of current flow may differ between the current that has a primary value and the current that has a secondary current value.

[0239] In particular, for example, the first data w i (k-1) j (k) The values ​​are "-1", "0", and "1". If either option is chosen, the circuit MC should be designed so that either the first current value or the second current value becomes zero. It is preferable to construct MCr. Note that the first data w i (k-1) j (k) Analog When the value can take the form of a "negative analog value", "0", or a "positive analog value", Furthermore, the first or second current value can also be obtained as an analog value.

[0240] By the way, if you run from wiring OL[j] or wiring OLB[j] to wiring VE via circuit MC, The current flows from wiring OL[j] or wiring OLB[j] through circuit MCr to wiring VEr When the current flowing through it is made equal to the current flowing through it, the transistor may be affected by the manufacturing process of the transistor, etc. Because the characteristics of the zista can vary, the potential held in the circuit MC and the potential held in the circuit MCr The potential and may not be equal. A semiconductor device according to one aspect of the present invention is a transistor Even if there is variation in the characteristics of the terminals, the circuit MC can be obtained from the wiring OL[j] or wiring OLB[j]. The amount of current flowing through wiring VE via the circuit is determined from wiring OL[j] or wiring OLB[j]. The amount of current flowing through the wiring VEr via MCr can be made approximately equal.

[0241] Furthermore, in this specification and other documents, the current corresponds to the information held in the holding part HC and the holding part HCr. Alternatively, voltage, etc., may be a positive current or a positive voltage, or a negative current or a negative voltage. It could be expressed as voltage, zero current, or zero voltage, or a mixture of positive, negative, and zero. It may be present. In other words, for example, the current corresponding to the information held in the holding part HC as described above. Alternatively, it has the function of outputting voltage or other signals to either wiring OL[j] or wiring OLB[j]. The circuit MCr transmits current or voltage, etc., according to the information held in the holding part HCr, to the wiring O The statement "has the function of outputting to L[j] or the other side of the wiring OLB[j]" means "holding Current, voltage, etc., according to the information held in part HC, are transmitted to wiring OL[j] or wiring OLB[ The circuit MCr has the function of discharging from one side of j, and the circuit MCr responds to the information held in the holding part HCr. A function that discharges the current, voltage, etc., from the other end of the wiring OL[j] or wiring OLB[j]. This can be rephrased as "having..."

[0242] The wiring X1L[i] and X2L[i] shown in Figure 10B correspond to the wiring XLS[i] in Figure 10A. This corresponds to ]. Note that the second data z input to circuit MP[i,j] i (k-1) is, For example, the potential or current of the wiring X1L[i] and X2L[i] respectively This is how it is defined. Therefore, for example, the circuits MC and MCr have wiring X1L[i] and wiring Through line X2L[i], the second data z i (k-1) Each corresponding potential is input.

[0243] Circuit MC is electrically connected to wiring OL[j] and wiring OLB[j], and circuit MCr is connected to wiring The lines OL[j] and OLB[j] are electrically connected. Circuits MC and MCr This depends on the potential or current input to wiring X1L[i] and wiring X2L[i]. , wiring OL[j] and wiring OLB[j], first data w i (k-1) j (k) and the second Data Z i (k-1) It has the function of outputting a current or potential corresponding to the product of [the specified value]. A typical example is the output destination of the current from circuit MC and MCr, which is wiring X1L[i] and wiring It is determined by the potential of X2L[i]. For example, circuit MC and circuit MCr are determined by circuit M The current output from C flows to either wiring OL[j] or wiring OLB[j], and circuit MC The current output from r flows to the other side of wiring OL[j] or wiring OLB[j]. This is the circuit configuration. In other words, the currents output from circuit MC and circuit MCr are... The current flows through different wiring, not the same wiring. In some cases, no current flows through either the wiring OL[j] or the wiring OLB[j].

[0244] For example, the second data z i (k-1) It can take one of three values: "-1", "0", or "1". Let's consider a case. For example, the second data z i (k-1) If it is "1", then circuit MP is, The circuit MC and wiring OL[j] are made conductive, and the circuit MCr and wiring OLB[j] are made conductive. Ensure continuity. Second data z i (k-1) If it is "-1", then circuit MP is circuit M The circuit between C and wiring OLB[j] is conductive, and the circuit between MCr and wiring OL[j] is conductive. This represents the state. Second data z i (k-1) If it is "0", then the circuit MC and MCr respectively To prevent the current output by this from flowing through either the wiring OL[j] or OLB[j] Therefore, circuit MP is between circuit MC and wiring OL[j], and between circuit MC and wiring OLB[j] The connection between ] and OL[j] is made non-conductive, and the connection between circuit MCr and wiring OL[j], and between circuit MC and wiring The connection between the line OLB[j] and the other line is made non-conductive.

[0245] An example of combining the above actions is shown below. Data 1 w i (k-1) j (k) The place of "1" In this case, the wiring OL[j] or wiring OLB[j] is routed through circuit MC to wiring VE[j]. Current may flow through circuit MCr to wiring OL[j] or wiring OLB[j] No current flows through the wiring VEr[j]. First data w i (k-1) j (k) is "-1" In this case, the wiring OL[j] or wiring OLB[j] is routed through circuit MC to wiring VE[j]. No current flows through the circuit MCr from wiring OL[j] or wiring OLB[j] to wiring V Current may flow through Er[j]. Then, the second data z i (k-1) The place of "1" In this case, the connection between circuit MC and wiring OL[j], and between circuit MCr and wiring OLB[j] The connection becomes conductive. Second data z i (k-1) If it is "-1", then the circuit MC and wiring Conduction occurs between OLB[j] and the circuit MCr and the wiring OL[j]. Based on the above, the first data w i (k-1) j (k) and the second data z i (k-1) The product of is positive When the value is such that current flows from wiring OL[j] to wiring VE[j] via circuit MC, Alternatively, current flows from wiring OL[j] to wiring VEr[j] via circuit MCr. It will be one or the other. 1st data w i (k-1) j (k) and the second data z i (k-1) product If the value is negative, current flows from wiring OLB[j] to wiring VEr[j] via circuit MCr. A current flows, or current flows from wiring OLB[j] to wiring VE[j] via circuit MC. It will be either ru or ru. First data w i (k-1) j (k) and the second data z i (k- 1) If the product of the two values ​​is zero, then the wiring VE[ from wiring OL[j] or wiring OLB[j] No current flows through [j], and no current flows from wiring OL[j] or wiring OLB[j] to wiring VEr[j]. The flow isn't working.

[0246] To illustrate the above example with a concrete example, the first data w i (k-1) j (k) is "1" That's the second data z i (k-1)If it is "1", for example, from circuit MC to wiring OL[ A current I1[i, j] with a first current value flows through [j], and from circuit MCr to wiring OLB[j] A current I2[i,j] with a second current value flows. In this case, the magnitude of the second current value is, for example, The result is zero. First data w i (k-1) j (k) The second data is "-1", taz i (k-1) If it is "1", for example, the second power supply from circuit MC to wiring OL[j] A current I1[i, j] with a current value flows, and the first current value is sent from the circuit MCr to the wiring OLB[j]. A current I2[i,j] flows. At this time, the magnitude of the second current value is, for example, ze It is R. First data w i (k-1) j (k) The second data z is "0". i (k- 1) If it is "1", then a current I1[i] with a second current value is drawn from the circuit MC to the wiring OL[j]. A current I2[i,j] flows from the circuit MCr to the wiring OLB[j], and a current I2[i,j] with a second current value flows. A current flows. In this case, the magnitude of the second current value is, for example, zero.

[0247] Also, the first data w i (k-1) j (k) The second data z is "1", i (k-1) If it is "-1", then the current I1[i A current I2[i,j] with a second current value flows from circuit MCr to wiring OL[j]. It flows. In this case, the magnitude of the second current value is, for example, zero. First data w i (k-1) j (k) The second data z is "-1", and i (k-1) In the case where is "-1" In total, a current I1[i,j] with a second current value flows from the circuit MC to the wiring OLB[j], and the circuit A current I2[i,j] with a first current value flows from MCr to wiring OL[j]. At this time, The magnitude of the second current value is, for example, zero. First data w i (k-1) j (k) The second data z is "0". i (k-1) If it is "-1", then wiring from the circuit MC A current I1[i,j] with a second current value flows through OLB[j], and the wiring OL[ from circuit MCr A current I2[i, j] with a second current value flows through j]. At this time, the magnitude of the second current value is One example is zero.

[0248] Also, the second data z i (k-1) If it is "0", then between circuit MC and wiring OL[j] Furthermore, the circuit MC and the wiring OLB[j] become non-conductive. Similarly, circuit MCr The connection between circuit MCr and wiring OL[j], and the connection between circuit MCr and wiring OLB[j] are in a non-conductive state. Yes. Therefore, the first data w i (k-1) j (k) Regardless of the value, the circuit MC No current is output from circuit MCr to wiring OL[j] and wiring OLB[j].

[0249] Thus, the first data w i (k-1) j (k) and the second data z i (k-1) The product of is positive When the value is taken, current is sent to wiring OL[j] from either circuit MC or circuit MCr. The following is flowed. Specifically, the first data w i (k-1) j (k) If the value is positive, then circuit M Current flows from C to wiring OL[j], and the first data w i (k-1) j (k) If the value is negative Current flows from circuit MCr to wiring OL[j].

[0250] Meanwhile, the first data w i (k-1) j (k) and the second data z i (k-1) The product of is a negative value When taking the current, current flows from either circuit MC or circuit MCr to wiring OLB[j]. It flows. Specifically, the first data w i (k-1) j (k) If the value is positive, the circuit MC Current flows from the wiring OLB[j], and the first data w i (k-1) j (k) If the value is negative Current flows from circuit MCr to wiring OLB[j].

[0251] Therefore, output from multiple circuits MC or multiple circuits MCR connected to wiring OL[j] The sum of the currents generated will flow through wiring OL[j]. In other words, in wiring OL[j] This results in a current flowing that corresponds to the sum of positive values. Meanwhile, connected to wiring OLB[j] The sum of the currents output from multiple circuit MCs or multiple circuit MCrs is equal to the wiring OLB[j] This means that current will flow through the OLB[j] wiring, which is equivalent to the sum of negative values. This will happen.

[0252] As a result of the above operation, a current equivalent to the sum of positive values ​​flows through the wiring OL[j], and negative values The sum of the currents flows through wiring OLB[j]. The current flowing through wiring OL[j] and the wiring The sum-of-accumulate operation is completed by calculating the difference in current flowing through OLB[j].

[0253] At this time, the value of the current flowing through wiring OL[j] is greater than the value of the current flowing through wiring OLB[j] If the value is large, it can be determined that the sum-of-products operation result will take a positive value. Current flowing through wiring OL[j] If the value of is less than the value of the current flowing through the wiring OLB[j], the sum-of-products result will be negative. It can be determined that a value is taken. The value of the current flowing through wiring OL[j] and the current flowing through wiring OLB[j] If the current values ​​are the same or approximately the same, the sum-of-products calculation result can be determined to be zero. ru.

[0254] In the circuit ACTF[j] where wiring OL[j] and wiring OLB[j] are electrically connected, the present invention By using the AD converter 100 according to one embodiment, the sum-of-accumulate result is converted to positive and negative signed digital It can efficiently convert to a signal.

[0255] Note that the second data z i (k-1) If it is one of the two values ​​among "-1", "0", or "1", For example, the same applies to binary values ​​such as "-1" and "1", or binary values ​​such as "0" and "1". It can be made to work. Similarly, the first data w i (k-1) j (k) is "-1", If the binary value is either 0" or 1", for example, if the binary value is 1"-1" and 1", Alternatively, the same operation can be performed for the binary values ​​"0" and "1".

[0256] Note that the first data w i (k-1) j (k) This is an analog value, or a multi-bit (multi-level) value. Digital values ​​can also be used. For example, instead of "-1", a "negative analog value" can be used, and You may use a "positive analog value" instead of "1". In this case, the circuit is MC or circuit is M. The magnitude of the current flowing from Cr is also shown in the first data w i (k-1) j (k) Depending on the absolute value of the value This will result in an analog value.

[0257] Figure 11A shows an example of a circuit configuration that can be applied to circuit MP. Circuit MP consists of circuit MC and circuit M It contains Cr. Circuit MC has transistors M1 to M5 and capacitance C1. The retaining part HC is composed of transistor M2, transistor M5, and capacitor C1. .

[0258] Circuit MCr has almost the same circuit configuration as circuit MC. Therefore, the rotation of circuit MCr To distinguish them from the circuit elements of the circuit MC, the designation "r" is added to the path elements. It is.

[0259] In Figure 11A, transistors M1 to M5 are shown as having a multi-gate structure with a back gate. It is written as an n-channel transistor. Therefore, transistor M shown in Figure 11A Each of transistors 1 through M5 comprises a first gate and a second gate. Also, transistor M3 And in transistor M4, the channel length and channel width of both are equal. It is preferable that it be simple.

[0260] Transistors M1 to M5 shown in Figure 11A have back gates. However, the connection configuration of the back gate is not shown in the diagram. The destination of the air connection can be determined during the design phase. For example, a traffic light with a back gate. In a transistor, the gate and back gate are used to increase the on-current of the transistor. They may be electrically connected. For example, the gate and back gate of transistor M2 may be electrically connected. It is also acceptable to connect them electrically.

[0261] Furthermore, in a transistor having a back gate, the threshold voltage of the transistor is To vary the backgauge, or to reduce the off-current of the transistor, An arbitrary potential may be applied to the transistors. Note that transistors M1 to M5 have back gates. It may also be a transistor that does not have a single gate structure. In other words, as a transistor with a single gate structure That's also good. Also, some transistors have a back gate, and some other transistors have a back gate. A configuration without a lock gate is also acceptable. For details on these configurations, please refer to Figure 11A. Not only the transistors listed, but also the transistors listed in other parts of the specification, The same applies to transistors illustrated in other drawings.

[0262] Furthermore, the transistor according to one aspect of the present invention may be a transistor of various structures. This is possible. Therefore, there are no restrictions on the type of transistor used. As an example of a transistor... This refers to transistors having single-crystal silicon, or amorphous silicon, polycrystalline silicon, Microcrystalline silicon (also called nanocrystal or semi-amorphous silicon) Transistors having non-single-crystal semiconductor films, such as those shown above, can be used. Thin-film transistors (TFTs) made by thinning these semiconductors can be used. Using TFTs offers various advantages. For example, it is lower than that of single-crystal silicon. Because it can be manufactured at low temperatures, it is possible to reduce manufacturing costs or to use larger manufacturing equipment. Because the manufacturing equipment can be made larger, it is possible to manufacture on large substrates. Therefore, a large number of units can be manufactured simultaneously. Because it can manufacture display devices, it can be produced at a low cost. Alternatively, because the manufacturing temperature is low, A substrate with low thermal properties can be used. Therefore, transistors can be placed on a light-transmitting substrate. It is possible to manufacture this. Alternatively, light in a display element using a transistor on a light-transmitting substrate. Transmittance can be controlled. Alternatively, because the transistor's film thickness is thin, the transistor A portion of the formed film can transmit light. Therefore, improving the aperture ratio... It is possible.

[0263] Furthermore, the semiconductor in which the transistor channel is formed is composed primarily of a single element. This applies not only to single-component semiconductors, but also to compound semiconductors (e.g., SiGe, GaAs, etc.), These are oxide semiconductors (e.g., Zn-O, In-Ga-Zn-O, In-Zn-O, In-S nO(ITO), Sn-O, Ti-O, Al-Zn-Sn-O(AZTO), In-S Materials such as n-Zn-O can be used. Note that these semiconductor materials are transient In addition to being used as a semiconductor in which channels are formed, it can also be used for other applications. It can also be used as a resistive element or a light-transmitting electrode. Because they can be deposited or formed simultaneously with the transistors, manufacturing costs are reduced. can.

[0264] Furthermore, organic semiconductors or carbon nanotubes can be used as semiconductor materials. These methods allow transistors to be formed on a flexible substrate. Devices using transistors containing organic semiconductors or carbon nanotubes are shock-resistant. It can be done.

[0265] Furthermore, in one aspect of the present invention, transistors of various structures can be used. This is possible. For example, planar type, fin type, tri-gate type. Gate type, top gate type, bottom gate type, double gate type (gates above and below the channel) Various configurations are possible, such as having a (T) arranged. Also, in one aspect of the present invention Examples of transistors involved include MOS transistors, junction transistors, and bipolar transistors. Transistors can be used. MOS-type transistors are used as transistors. This allows the area occupied by the transistor to be reduced. Therefore, a large number of transistors It can be equipped with a zista. By using a bipolar transistor as the transistor... This allows for the flow of a large current. Therefore, the circuit can be operated at high speed. Furthermore, MOS transistors and bipolar transistors are mixed on a single substrate. It may be formed in this way. This makes it possible to achieve low power consumption, miniaturization, and high-speed operation. ru.

[0266] In the circuit MC of Figure 11A, the first terminal of transistor M1 (source or drain) The (side) is electrically connected to wiring VE. The second terminal (source or) of transistor M1. (The other side of the drain) is the first terminal of transistor M3 and the first terminal of transistor M4 It is electrically connected to the first terminal of capacitor C1. One of the pair of electrodes that make up the pair is electrically connected to the first terminal of transistor M2. The second terminal of capacitance C1 (the other of the pair of electrodes that make up the capacitance) is electrically connected to wiring VE. They are connected. The second terminal of transistor M2 is connected to the wiring IL and the terminal of transistor M5. It is electrically connected to terminal 1. The gate of transistor M2 is electrically connected to wiring WL. The second terminal of transistor M3 is electrically connected to wiring OL, and the transistor The gate of M3 is electrically connected to wiring X1L. The second terminal of transistor M4 is The gate of transistor M4 is electrically connected to wiring OLB, and the gate of transistor M4 is electrically connected to wiring X2L. It is continued. The second terminal of transistor M5 is connected to the second terminal of transistor M1, It is electrically connected to the first terminal of transistor M3 and the first terminal of transistor M4. The gate of the M5 generator is electrically connected to the wiring WL.

[0267] This section describes the connection configuration of circuit MCr, which differs from that of circuit MC. The second terminal is electrically connected to wiring OLB, not wiring OL, and is the terminal of transistor M4r. Terminal 2 is electrically connected to wiring OL, not wiring OLB. Transistor M1r The first terminal of the capacitor C1r and the first terminal of the capacitor C1r are electrically connected to the wiring VEr.

[0268] The channel length and channel width of transistors M1, M2, M3, M4, and M5, etc. The sizes are those of transistors M1r, M2r, M3r, M4r, and M5r, respectively. It is preferable that they be equal. By using such a configuration, the layout can be efficiently arranged. There is a possibility that this will happen.

[0269] Furthermore, in the holding part HC shown in Figure 11A, the gate of transistor M1 and the first capacitor C1 The electrical connection point between the terminal and the first terminal of transistor M2 is defined as node n1. In the holding part HCr, the gate of transistor M1r and the second terminal of capacitor C1r, The electrical connection point between the first terminal of transistor M2r and node n1r is defined as node n1r.

[0270] The holding part HC has the function of holding the potential corresponding to the first data. The writing to the position is done with transistor M2 in the ON state and transistor M5 in the OFF state, This is done by supplying a potential corresponding to the first data from line IL to node n1. By turning off the transistor M2, node n1 maintains a potential corresponding to the first data. It can be done.

[0271] Similar to the holding part HC, the holding part HCr also has the function of holding the potential corresponding to the first data. Writing the potential to the holding part HCr is done with transistor M2r in the ON state, Turn off M5r and supply a potential corresponding to the first data from the wiring ILB to node n1r. This is done by turning off transistor M2r, which then turns off node n1 The potential corresponding to the first data is maintained in r.

[0272] Transistor M2 maintains the potential of node n1 for a long time, so it has a low off-current. It is preferable to use a zista. A transistor with low off-current is, for example, an OS A transistor can be used. Also, as transistor M2, it has a back gate. A transistor is applied, and a low-level potential or negative voltage is applied to the back gate, and the threshold A configuration may be used in which the value voltage is shifted to the positive side to reduce the off-current. Transis The same applies to the M2r.

[0273] Wiring VE and wiring VEr function as wiring that supplies a constant voltage. This refers to transistor M3, transistor M3r, transistor M4, or transistor If M4r is an n-channel transistor, then Vss, GND, or something else. This can be a low-level potential, for example.

[0274] Furthermore, the voltages supplied by wiring VE and wiring VEr may be different from each other or the same. It is also acceptable to do so if the voltage supplied by each wire is the same. It may be shared.

[0275] Furthermore, a modified version of the circuit MP in Figure 11A is shown in Figure 11B. The circuit MP shown in Figure 11B is a traverse The first terminal of transistor M5 is the first terminal of transistor M2, and the gate of transistor M1 is It is electrically connected to the first terminal of capacitance C1. The circuit MP shown in Figure 11B is shown in Figure 11A. It can operate similarly to the circuit MP shown.

[0276] Furthermore, the holding part HC and the holding part HCr, which hold the first data which is the weight coefficient, are equipped with SRAM. (Static Random Access Memory), Phase-Change Memory (PCM) Phase-Change Memory (RRAM), Resistive Random-Access Memory (ReRAM) (Istive Random Access Memory), Magnetoresistive Memory (MRA) M:Magnetoresistive Random Access Memory) Ferroelectric memory (FeRAM: Ferroelectric Random Accelerator) You may also use ss Memory, etc.

[0277] A modified version of circuit MP shown in Figure 11A is shown in Figure 12. As shown in Figure 12, one wire is arranged Use one line as line OL or wiring IL, and the other wiring as wiring OLB or wiring ILB May be used. In addition, wiring X2L, transistor M4, transistor M4r, transistor The configuration may also be one in which the sta M5 and transistor M5r are not provided. The circuit shown in Figure 12 is M. At P, the second terminal of transistor M2 and the second terminal of transistor M3 are connected to OL. It is electrically connected to (wiring IL). Also, the second terminal of transistor M2r and the transistor The second terminal of the M3r converter is electrically connected to the OLB (ILB) wiring.

[0278] This embodiment can be appropriately combined with other embodiments shown in this specification and elsewhere.

[0279] (Embodiment 3) The sum-of-products result obtained by a neuron is often output through an activation function. As activation functions, the linear ramp function (ReLU function), sigmoid function, and step function are used. Such are known. An AD conversion device 100 according to one aspect of the present invention has an AD conversion function in addition to the AD conversion function. Furthermore, it can also implement the functionality of the ReLU function.

[0280] Figure 13 is a flowchart illustrating the operation of the AD converter 100 with added ReLU function functionality. This is a chart. Using Figure 13, the operation of the AD converter 100 with added ReLU function functionality is shown. Let's explain the operation. An example of the operation of the AD converter 100 has already been described in Embodiment 1. Therefore, in this embodiment, we will explain the differences from the operation example described in Embodiment 1.

[0281] [Step S211] After step S203b is completed, should the AD converter 100 be made to function as a ReLU function? Determine whether it is Yes or No. If you do not want it to function as a ReLU function, proceed to step S2. After performing step 04b, proceed to step S205.

[0282] [Step S212] When the AD converter 100 is made to function as a ReLU function, the digital signal is (000 Set 00000)2. Then, perform step S205.

[0283] In this way, when the differential current is negative (when the sign bit is 1), the value of the differential current is determined by... It outputs (100000000)2 as a signed digital signal. Also, the differential current is If the result is positive (sign bit is 0), the DA conversion unit 130b performs a sequential comparison and the difference current It generates a digital signal corresponding to the value.

[0284] Figure 14A shows the digital output generated when the AD converter 100 is configured to function as a ReLU function. This graph shows the change in the Tal signal. In Figure 14A, the horizontal axis shows the differential current, and the vertical axis shows the output. This shows the digital signal (quantized value). Figure 14A shows the case where the differential current is negative. If the signal output is 0, and the differential current is positive, a digital signal corresponding to the value of the differential current is output. It shows that they are being forced to do something.

[0285] Since the AD converter 100 can also function as a ReLU function, a separate ReLU function is provided. It is not necessary. Therefore, the semiconductor device equipped with the AD converter 100 can reduce power consumption. Furthermore, the semiconductor device equipped with the AD converter 100 can reduce its occupied area.

[0286] Furthermore, if the ReLU function is added to the AD converter 100, the DA converter 130a Since this operation does not occur, the power supply to the DA conversion unit 130a may be stopped (Figure 14B). (See reference.) By stopping the power supply to the DA conversion unit 130a, power consumption can be further reduced. Cut.

[0287] This embodiment can be appropriately combined with other embodiments shown in this specification and elsewhere.

[0288] (Embodiment 4) This embodiment provides an example of a display device configuration to which the semiconductor device described in the above embodiment can be applied. This will be explained. As an example, the AD of the display device of the semiconductor device described in the above embodiment. An example configuration for application to a conversion circuit will be described. Using such a semiconductor device is effective in reducing the occupied area and power consumption.

[0289] <Example of display device configuration> Figure 15 is a block diagram showing an example of the configuration of a display device. The display device 200 has a pixel section 210, It has a functional circuit 220A and a peripheral circuit 220B.

[0290] The functional circuit 220A includes the CPU 230, control circuit 231, power supply circuit 232, and image processing circuit 2 It has 33 and memory 234.

[0291] The CPU 230 is a circuit that executes instructions and comprehensively controls the display device 200. The instructions executed by CPU230 are instructions input from the outside and instructions stored in internal memory. This is an instruction. The CPU 230 sends signals to control the control circuit 231 and the image processing circuit 233. Generates. Based on the control signals of the CPU 230, the control circuit 231 controls the operation of the display device 200. Controls the peripherals. The control circuit 231 controls the peripherals so that the processing determined by the CPU 230 is executed. It controls circuit 220B, power supply circuit 232, image processing circuit 233, and memory 234. Circuit 231 receives, for example, various synchronization signals that determine the timing of screen refreshes. Synchronization signals include, for example, a horizontal synchronization signal, a vertical synchronization signal, and a reference clock. There are signals, etc., and the control circuit 231 generates control signals for the peripheral circuit 220B from these signals. The power supply circuit 232 has the function of supplying power voltage to the pixel unit 210 and the peripheral circuit 220B. To possess.

[0292] The pixel section 210 consists of multiple pixels 211, multiple wiring GLs, multiple wiring SLs, and multiple wirings It has lines ML. Multiple pixels 211 are arranged in an array. Multiple wiring GL, SL ML is provided according to the arrangement of multiple pixels 211. Wiring GL is arranged vertically. Wiring SL and ML are arranged horizontally. Wiring GL is the gate line and scan line. These are sometimes called selection signal lines, etc. Wiring SL is sometimes called source line, data line, etc. There is a wiring ML provided for monitoring pixel 211, for example, This can be called monitor wiring.

[0293] The peripheral circuit 220B includes a gate driver circuit 221 and a source driver circuit 222, and It has a nitting circuit 223 and an AD conversion circuit 224.

[0294] The gate driver circuit 221 is a circuit for driving wiring GL and supplies power to wiring GL. It has the function of generating signals. The source driver circuit 222 is for driving the wiring SL. It is a circuit and has the function of generating a signal to be supplied to wiring SL. Monitor circuit 223 is wiring M It has the function of detecting the analog signal flowing through L. This is a circuit for converting the analog signal output from the Nita circuit 223 into a digital signal. The AD conversion circuit 224 outputs the signal CMOUT to the image processing circuit 233.

[0295] In the display device 200, the AD conversion device 100 of Embodiment 1 is applied to the AD conversion circuit 224. Therefore, the display device 200 was designed to reduce the occupied area and power consumption. It is a display device.

[0296] The image processing circuit 233 processes the video signal input from an external source to generate the data signal VDATA. It has the function of generating. The data signal VDATA is a digital signal that represents grayscale. The image processing circuit 233 has a function to correct the data signal VDATA using the signal CMOUT. The source driver circuit 222 processes the data signal VDATA and each wiring SL It has the function of generating data signals to be supplied to the image processing circuit 233. It is provided to store the data necessary for processing. Memory 234 contains, for example, For example, the signal CMOUT, the data signal VDATA, or the video signal input from an external source is It will be delivered.

[0297] The analog signal flowing through the wiring ML is a tiny current ranging from a few nA to several hundred nA, but AD conversion By using the AD converter 100 of Embodiment 1 in circuit 224, the display device 200 is This enables high-precision detection of analog signals and high-precision correction of data signals (VDATA). ru.

[0298] Figure 16A shows the pixel section 210, the functional circuit 220A, and the peripheral circuit of the display device 200. This is a schematic diagram illustrating the arrangement of 220B. In Figure 16A, as an example, layer 201 and Figure 16A illustrates a display device 200 in which each component is provided across layers 202 and . In this configuration, layer 202 is provided, for example, stacked on top of layer 201. Between layers 02, an interlayer insulator or a conductor for making an electrical connection between different layers is provided. It is possible to do so.

[0299] The transistor provided in layer 201 is, for example, a transistor having silicon in the channel formation region. It can be made into a transistor (also called a Si transistor), for example in the channel formation region A transistor having single-crystal silicon can be made. In particular, layer 201 is provided As a transistor, a transistor having single-crystal silicon in the channel formation region is used. This allows the on-current of the transistor to be increased. Therefore, layer 201 has It is preferable because it can drive the circuit at high speed. Also, Si transistors are channel Because it can be formed with microfabrication of a length of 3nm to 10nm, CPUs and GPs Display equipped with functional circuits such as accelerators (U), application processors, etc. This can be referred to as device 200.

[0300] The transistor provided in layer 202 can be, for example, an OS transistor. In the OS transistor, indium is used in the channel formation region, and element M (element M is aluminum) An oxide containing at least one of the following: ttrium, gallium, yttrium, or tin, and zinc. It is preferable to use a transistor that has an off current. It has the characteristic of being extremely low. Therefore, especially the transistors provided in the pixel circuits of the display unit When an OS transistor is used as the transistor, the analog data written to the pixel circuit It is preferable because it can be preserved for a long period of time.

[0301] Layer 201 is provided with a functional circuit 220A and a peripheral circuit 220B. The transistor 203 is a Si transistor having silicon in the channel formation region 205. Si transistors can increase the on-current of the transistor. The functional circuit 220A includes a CPU 230, a control circuit 231, a power supply circuit 232, and an image processing unit. Circuit 233, memory 234, and the gate driver circuit of peripheral circuit 220B Path 221, and source driver circuit 222, monitor circuit 223 and AD conversion circuit 22 It can drive 4 at high speed.

[0302] Layer 202 is provided with a pixel section 210 having multiple pixels 211. The transistor 204 has an oxide (oxide semiconductor) that functions as a semiconductor in the channel formation region 206. It is an OS transistor having a conductor. The OS transistor is written to pixel 211. The data can be retained for a long period of time. Furthermore, the light emission of red, green, and blue light from pixel 211 is controlled. It functions as a sub-pixel.

[0303] Figure 16B shows that some of the circuits of the peripheral circuit 220B located in layer 201 are moved to layer 202. A schematic diagram of the case where it is implemented is shown. In Figure 16B, the gate driver circuit 221 and the sourced The diagram shows a configuration in which the driver circuit 222 is provided in layer 202. - The driver circuit 222 performs some functions, such as the signal output by the source driver 222. A configuration can be implemented in layer 202 that provides a demultiplexer to distribute the wiring to SL.

[0304] <Example of pixel configuration> Figure 17A is a circuit diagram showing an example of pixel 211, and Figure 17B shows pixel 211 as shown in Figure 17A. This is a timing chart illustrating an example of operation.

[0305] Figure 17A is arranged in the kth row and jth column (where k is an integer between 2 and m, and j is an integer between 2 and n). This shows the pixel 211 to be placed. Pixel 211 is located on the wiring GL, SL, ML, and ANL. It is electrically connected to transistors M25 to M27 and capacitive element C. 11 and a light-emitting element EL1 are included. In this specification, the term "element" is used to mean "de It can sometimes be rephrased as "vice." For example, display elements, light-emitting elements, and liquid crystals. The elements can be rephrased as, for example, display devices, light-emitting devices, and liquid crystal devices. ru.

[0306] The light-emitting element EL1 has a pair of terminals (anode and cathode). In this case, an element capable of controlling brightness by current or voltage can be used. EL1 is an LED (Light Emitting Diode) and OLED (Organic Light Emitting Diode) is a typical example. For example, in the case of an OLED, the light-emitting element EL1 is EL (electroluminescent). It has layers. The EL layer is placed between the anode and cathode and consists of one or more layers. The EL layer includes at least a layer containing a light-emitting substance (light-emitting layer). The EL layer is used for light emission. Light-emitting elements are sometimes called EL elements. A display device that applies EL elements to pixels is called an EL display. It is sometimes called a display device. In particular, a light-emitting element having an organic EL layer is called an organic EL element. Display devices using EL elements are sometimes called organic EL display devices. Child EL1 can be an organic EL element.

[0307] The transistors M25 to M27 shown in Figure 17A can be OS transistors. Transistors M25 through M27 are made of Si transistors, some or all of which are Si transistors. It is also acceptable. In Figure 17A, transistors M25 to M27 are n-channel type transistors. However, some or all of these may be p-channel transistors. Rangistas M25 to M27 have a back gate that is electrically connected to the gate. By adopting this device structure, the current driving capability of transistors M25 to M27 is It can be improved. Some or all of transistors M25 to M27 have backgain A transistor without a transistor is also acceptable.

[0308] Transistor M25 is located between the gate (node ​​N12) of transistor M26 and wiring SL. This is a pass transistor that connects the wiring ML and the light-emitting element EL1. This is a pass transistor that connects to the anode (node ​​N11). Transistor M 26 is a drive transistor and functions as a current source supplied to the light-emitting element EL1. The brightness of the light-emitting element EL1 is adjusted by the magnitude of the drain current of the transistor M26. Capacitive element C11 is a retaining capacitance that maintains the voltage between node N11 and node N12.

[0309] Next, we will explain an example of the operation of pixel 211. The wiring SL is connected to the data signal, voltage Vda The following is input. Voltage Vda is the voltage corresponding to the grayscale of the video signal. [k] in Figure 17B, [k+1] represents the data signal Vd input to the k-th row and the (k+1)th row of pixels 211, respectively. This indicates that it is a.

[0310] Period P1 is the write operation period, during which the light-emitting element EL1 is not illuminated. Wiring ANL is A voltage Vano is applied, and a voltage Vcat is applied to the cathode of the light-emitting element EL1. Line ML is electrically connected to the power line that supplies voltage V0. The wiring GL is at a high level. Turn on transistors M25 and M26. Connect the voltage Vda of the wiring SL to node N12. A drain current of a magnitude corresponding to the voltage Vda flows through transistor M26. ru.

[0311] Furthermore, voltages Vano, V0, and Vcat satisfy the following equations (b1)-(b3): It is preferable to set it so that it adds up. In the following formula, the voltage V thE is the light-emitting element EL1 This is the threshold voltage, and the voltage V th2 This is the threshold voltage of transistor M26. V0 <Vcat+V thE (b1) Vano>V0+V thE (b2) Vano>Vcat+V thE +V th2 (b3)

[0312] (b1) and (b2) are true, so during period P1 (writing period), transistor M27 Even when it is ON, the drain current of transistor M26 is directed to the wiring M instead of the light-emitting element EL1. L can be prioritized for flow. By satisfying (b3), during period P2 (light emission period), the wiring Because a potential difference is generated between ANL and the cathode of the light-emitting element EL1, transistor M26 The drain current is supplied to the light-emitting element EL1, causing the light-emitting element EL1 to emit light. During period P2, transistors M25 and M27 are turned off.

[0313] Period P3 is the monitoring period for obtaining the drain current of transistor M26. Turn on transistors M25 and M27. Also, supply voltage V0 to wiring ML. The electrical connection to the power line is interrupted. The voltage at node N12 is voltage V in wiring SL. t h2 Apply a voltage that is higher than the specified value. Apply voltage Vano to the wiring ANL, and the light-emitting element A voltage Vcat is applied to the cathode of EL1. By driving the wiring SL etc. in this way, The drain current of transistor M26 is preferentially directed to the wiring ML rather than the light-emitting element EL1. It is possible.

[0314] Signal I is output from pixel 211 to wiring ML during period P3. MON During the luminescence period, the transition Includes the drain current flowing through M26. Signal I MON We analyze the data, and based on the analysis results, By correcting the voltage Vda of the signal, the brightness shift of pixel 211 can be corrected. .

[0315] It is not always necessary to perform the monitoring operation after the light emission operation. For example, in pixel 211, data After repeating the cycle of writing and lighting multiple times, the monitor operation is performed. It is possible to do this. Also, after the monitor operation, the data signal corresponding to the minimum grayscale value of 0 is generated. The light-emitting element EL1 may be set to a non-emitting state by writing to pixel 211.

[0316] Signal I MON This is input to the monitor circuit 223 shown in Figure 15. The monitor circuit 223 is Signal I MON It has the function of being able to control the output to the AD conversion circuit 224.

[0317] <Method for forming light-emitting elements> The following describes the shape of the light-emitting element EL1 provided in each of the pixels 211 of the pixel section 210. I will now explain the method.

[0318] Figure 18A shows the light-emitting elements EL_R, EL_G, and EL_B that can be applied to the light-emitting element EL1. A schematic diagram of the surface is shown. Light-emitting element EL_R is a light-emitting element that emits red light, and light-emitting element EL_G is green light. The light-emitting element that exhibits color, and the light-emitting element EL_B, are both light-emitting elements that exhibit blue light. Figure 18A To simplify the distinction between each light-emitting element, the R, G, and B codes are placed within the light-emitting region of each light-emitting element. It is marked with a symbol. Furthermore, the configuration shown in Figure 18A is referred to as the SBS (Side By Side) structure. It is also permissible to refer to them by name. Furthermore, the configuration shown in Figure 18A is referred to as red (R), green (G), and The example given is a configuration with three colors, including blue (B), but it is not limited to this. For example, 4 The configuration may have more than one color.

[0319] The light-emitting elements EL_R, EL_G, and EL_B are each arranged in a matrix. Figure 1 8A shows a so-called stripe arrangement, where light-emitting elements of the same color are arranged in one direction. Furthermore, the arrangement method of the light-emitting elements is not limited to this, and other arrangement methods such as delta arrangement and zigzag arrangement are also possible. You can apply the law, or you can use a pentile array.

[0320] As for the light-emitting elements EL_R, EL_G, and EL_B, we have OLED (Organic Light). QLED (Quantum-dot Li) is an Emitting Diode. It is preferable to use organic EL devices such as ght Emitting Diodes. i. The light-emitting materials used in EL elements include fluorescent materials and phosphorescent materials. Substances (phosphorescent materials), inorganic compounds (quantum dot materials, etc.), substances exhibiting thermally activated delayed fluorescence ( Thermally activated delayed fluorescence Examples include orescence (TADF material).

[0321] Figure 18B is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 18A.

[0322] Figure 18B shows cross-sections of the light-emitting elements EL_R, EL_G, and EL_B. L_R, EL_G, and EL_B are each provided on the insulating layer 251 and serve as pixel electrodes. It has a conductive element 252 and a conductive element 254 that functions as a common electrode.

[0323] The light-emitting element EL_R has an EL layer 253R between the conductor 252 and the conductor 254. The EL layer 253R is a luminescent organic compound that emits light having intensity in at least the red wavelength range. The EL layer 253G of the light-emitting element EL_G has strong properties in at least the green wavelength range. The EL layer 2 of the light-emitting element EL_B has a light-emitting element that emits light of a certain degree. 53B comprises a luminescent organic compound that emits light having intensity in at least the blue wavelength range. ru.

[0324] EL layer 253R, EL layer 253G, and EL layer 253B are each made of a luminescent organic compound. In addition to the layer containing (light-emitting layer), there are electron injection layer, electron transport layer, hole injection layer, and hole transport layer It is acceptable to have one or more of these.

[0325] A conductor 252 is provided for each light-emitting element. In addition, a conductor 254 is provided for each light-emitting element. It is provided as a continuous layer. Conductor 252 and conductor 2 which functions as a common electrode A conductive film that is transparent to visible light is used on one of the 54, and a reflective film is used on the other. A conductive film is used. By making the conductor 252 translucent and the conductor 254 reflective, the downward radiation It can be used as a bottom-emission type display device, and conversely, reflects the conductor 252. By making the conductive material 254 translucent, a top-emission type display device can be used. It can be placed in this manner. Furthermore, by making both the conductor 252 and the conductor 254 transparent... It can also be used as a double-sided injection (dual-emission) display device.

[0326] An insulating layer 255 is provided covering the end of the conductor 252. The end of the insulating layer 255 is A tapered shape is preferable.

[0327] EL layer 253R, EL layer 253G, and EL layer 253B are located on the upper surface of the conductor 252, respectively. It has a region in contact with the surface and a region in contact with the surface of the insulating layer 255. Also, the EL layer 253R The edges of EL layer 253G and EL layer 253B are located on the insulating layer 255.

[0328] As shown in Figure 18B, a gap is provided between the two EL layers between light-emitting elements of different colors. In this way, EL layer 253R, EL layer 253G, and EL layer 253B are mutually compatible. It is preferable that they are provided so as not to come into contact with each other. This allows two adjacent EL layers This effectively prevents current from flowing through it and causing unintended light emission (also known as crosstalk). This allows for increased contrast and a display with high display quality. This can be achieved.

[0329] EL layer 253R, EL layer 253G, and EL layer 253B are shadows such as metal masks. They can be differentiated using methods such as vacuum deposition with a mask. Alternatively, photolithography... These can also be differentiated using the raffia method. By using photolithography, This enables the creation of a display device with high resolution, which is difficult to achieve using a digital mask. It is possible.

[0330] Furthermore, a protective layer 2 covers the light-emitting elements EL_R, EL_G, and EL_B on the conductive material 254. A protective layer 256 is provided. The protective layer 256 prevents impurities such as water from diffusing to each light-emitting element from above. It has a function to prevent this from happening.

[0331] The protective layer 256 may be, for example, a single-layer structure or a multi-layer structure including at least an inorganic insulating film. This is possible. Examples of inorganic insulating films include silicon oxide films and silicon oxide nitride films. silicon nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film Examples include oxide films or nitride films such as hafnium oxide films. Alternatively, protective layer 256 Semiconductor materials such as indium gallium oxide and indium gallium zinc oxide are used. It may be present. Furthermore, the protective layer 256 may be produced using the ALD method, CVD method, or sputtering method. It can be formed using [this method]. For example, the protective layer 256 may include an inorganic insulating film. The examples shown are not limited to these. For example, the protective layer 256 may consist of an inorganic insulating film and an organic insulating film. A laminated structure with the above may also be used.

[0332] Figure 18C shows a different example from the one described above.

[0333] Figure 18C shows a light-emitting element EL_W that emits white light. The light-emitting element EL_W is conductive The body 252 and the conductor 254 have an EL layer 253W that emits white light.

[0334] For the EL layer 253W, for example, the respective emitted colors are selected so that they are complementary colors. Furthermore, a configuration can be formed by stacking two or more light-emitting layers. In addition, a charge generation layer can be placed between the light-emitting layers. A sandwiched, stacked EL layer, a so-called tandem structure EL layer, may also be used. By using a dem structure, it is possible to create a light-emitting element that can emit light with high brightness.

[0335] Figure 18C shows three light-emitting elements EL_W arranged side by side. Above the left light-emitting element EL_W A colored layer 257R is provided in the part. The colored layer 257R is a band that transmits red light. It functions as a pass filter. Similarly, the top of the central light-emitting element EL_W transmits green light. A translucent colored layer 257G is provided, and the upper part of the light-emitting element EL_W on the right transmits blue light. A colored layer 257B is provided. This allows the display device to display a color image. It is possible.

[0336] Here, between two adjacent light-emitting elements EL_W, there is an EL layer 253W and a conductor 254 These are separated. As a result, in two adjacent light-emitting elements EL_W, Current flows through the EL layer 253W, effectively preventing unintended light emission. In particular, as an EL layer of 253W, a charge generation layer is provided between the two light-emitting layers, and it is stacked. When using a type of EL element, the higher the resolution, that is, the smaller the distance between adjacent pixels. The more crosstalk is used, the more pronounced the effects become, leading to problems such as a decrease in contrast. Yes. Therefore, this configuration allows for both high resolution and high contrast. This enables the creation of a display device that incorporates these features.

[0337] The separation of the EL layer 253W and the conductor 254 is preferably performed by photolithography. This allows for narrowing the spacing between light-emitting elements, for example, in metal masks. Compared to using a shadow mask, it is possible to achieve a display device with a high aperture ratio. ru.

[0338] In the case of a bottom-emission type light-emitting element, between the conductor 252 and the insulating layer 251 A colored layer can be added.

[0339] Figure 18D shows a different example from the one described above. Specifically, Figure 18D shows a light-emitting element (EL). An insulating layer 255 is not provided between _R, light-emitting element EL_G, and light-emitting element EL_B. This is the configuration. This configuration allows for a display device with a high aperture ratio. Furthermore, The protective layer 256 covers the sides of the light-emitting elements EL_R, EL_G, and EL_B. This configuration is as follows. With this configuration, the light-emitting element EL_R, the light-emitting element EL_G, and the light-emitting element are configured as follows. This allows for the suppression of impurities (typically water, etc.) that could enter from the side of the EL_B element. Furthermore, in the configuration shown in Figure 18D, the conductor 252, the EL layer 253R, and the conductor The top shape of 254 roughly matches. Such a structure consists of a conductor 252 and an EL layer 253R. And after forming the conductive material 254, the entire structure can be formed at once using a resist mask or the like. Yes, it is possible. This process involves using the conductor 254 as a mask, the EL layer 253R, and the conductor Since this process involves machining the electrolytic body 252, it can also be called self-aligned patterning. Although the light-emitting element EL_R was explained here, light-emitting elements EL_G and light-emitting elements are also described. A similar configuration can be applied to EL_B.

[0340] Furthermore, in Figure 18D, a protective layer 258 is provided on top of the protective layer 256. Yes, there is. For example, a device capable of forming a highly covering film for the protective layer 256 (typically an ALD device). (etc.) are used to form the protective layer 258, which is a film with lower coverage than the protective layer 256. By forming it with a device (typically a sputtering device, etc.), the protective layer 256 and A gap 259 can be provided between the protective layer 258 and the gap 259. In other words, a gap 25 9 is between light-emitting element EL_R and light-emitting element EL_G, and between light-emitting element EL_G and light-emitting element E It is located between L_B and L_B.

[0341] Furthermore, the void 259 can contain, for example, air, nitrogen, oxygen, carbon dioxide, and Group 18 elements (representative). (This includes one of the following: helium, neon, argon, xenon, krypton, etc.) It has one or more. In addition, the void 259 is used, for example, when forming the protective layer 258. Gas may be present. For example, when the protective layer 258 is deposited by sputtering. The combined void 259 may contain one or more of the above-mentioned Group 18 elements. If a gas is present in void 259, the gas can be identified by gas chromatography or other methods. The following can be done. Alternatively, when the protective layer 258 is formed by sputtering, The protective layer 258 may also contain the gas used during sputtering. When the protective layer 258 was analyzed by energy-dispersive X-ray spectroscopy (EDX analysis), etc., Elements such as Gon may be detected.

[0342] Furthermore, if the refractive index of the gap 259 is lower than that of the protective layer 256, the light-emitting element EL_R, Light emitted from the light-emitting element EL_G or EL_B is transmitted between the protective layer 256 and the gap 2 It reflects at the interface with 59. As a result, light-emitting element EL_R, light-emitting element EL_G, or Light emitted from the optical element EL_B can be prevented from incident on adjacent pixels. This suppresses the mixing of different colored lights, thereby improving the image quality of the display device. It is possible.

[0343] In the configuration shown in Figure 18D, the region between the light-emitting element EL_R and the light-emitting element EL_G, Alternatively, the region between light-emitting element EL_G and light-emitting element EL_B (hereinafter simply referred to as the region between light-emitting elements) The distance between light-emitting elements can be narrowed. Specifically, the distance between light-emitting elements can be reduced to 1 μm or less. Preferably 500 nm or less, more preferably 200 nm or less, 100 nm or less, 9 0nm or less, 70nm or less, 50nm or less, 30nm or less, 20nm or less, 15nm or less , or it can be 10 nm. In other words, the side of the light-emitting element EL_R and the light-emitting element The distance between the side of EL_G, or the distance between the side of light-emitting element EL_G and the side of light-emitting element EL_B It has regions with spacing of 1 μm or less, preferably regions with spacing of 0.5 μm (500 nm) or less. More preferably, it has a region of 100 nm or less.

[0344] Furthermore, for example, if the void 259 contains air, the configuration shown in Figure 18D is an air-isolated system. It can be called an air isolation structure. By having an air isolation structure, While isolating the optical elements, it also minimizes the mixing or crosstalk of light from each light-emitting element. It can be suppressed.

[0345] Figure 19A shows a different example from the one described above. Specifically, the configuration shown in Figure 19A is as shown in Figure The configuration shown in 18D differs from the configuration of the insulating layer 251. The insulating layer 251 is made of light-emitting element EL_R During the processing of the light-emitting element EL_G and light-emitting element EL_B, a portion of the upper surface was scraped away, creating a recess. In addition, a protective layer 256 is formed in the recess. In other words, in a cross-sectional view, There is a region in which the lower surface of the protective layer 256 is located lower than the lower surface of the conductor 252. By having a region, from below, light-emitting element EL_R, light-emitting element EL_G, and light-emitting element EL_ This effectively suppresses impurities that could potentially enter B (typically water, for example). The above recesses are the addition of light-emitting elements EL_R, EL_G, and EL_B. Impurities (also called residues) that may adhere to the sides of each light-emitting element during the manufacturing process are removed by wet etching. These can be formed when removing them by methods such as the above. After removing the above-mentioned residue, the sides of each light-emitting element By covering it with a protective layer 256, a highly reliable display device can be created.

[0346] Further, FIG. 19B shows an example different from the above. Specifically, the configuration shown in FIG. 19B has an insulating layer 276 and a microlens array 277 in addition to the configuration shown in FIG. 19A. The insulating layer 276 has a function as an adhesive layer. When the refractive index of the insulating layer 276 is lower than the refractive index of the microlens array 277, the microlens array 277 can collect the light emitted from the light emitting element EL_R, the light emitting element EL_G, and the light emitting element EL_B. As a result, the light extraction efficiency of the display device can be improved. In particular, when the user views the display surface from the front of the display surface of the display device, a bright image can be visually recognized, which is preferable. As the insulating layer 276, various curable adhesives such as ultraviolet curable type photocurable adhesives, reaction curable adhesives, thermosetting adhesives, anaerobic adhesives, etc. can be used. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenol resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, EVA (ethylene vinyl acetate) resins, etc. In particular, materials with low moisture permeability such as epoxy resins are preferable. Also, a two-component mixed resin may be used.

[0347] <Configuration Example 1 of AD Conversion Circuit Having AD Conversion Device 100> FIG. 20 is a circuit diagram showing a configuration example of an AD conversion circuit 224 including the AD conversion device 100 described in Embodiment 1. The AD conversion circuit 224 includes a plurality of transistors M1 (M1[1] to M1[N], where N is a natural number of 1 or more), a plurality of AD conversion devices 100 (100[1] to 100[N]), a plurality of TRIBUF (tri-state buffer circuits) 262, and a circuit. It has a path SR (shift register).

[0348] In the following explanation, transistor M1 will be described as an n-channel transistor, but this is a development One aspect of this method is also applicable when transistor M1 is a p-channel type transistor. It is possible.

[0349] Signal I shown in Figure 20 MON (I MON [1]~I MON [N]) is the display device 200 The current value (analog signal) flowing through pixel 211 is included as information. AD converter 1 00 represents these signals I MON It converts this into a digital signal and outputs it as a CMOUT signal. It has a function.

[0350] Also, signal I shown in Figure 20 TEST This uses the value of a reference current (analog signal) as information. It includes. The AD converter 100 receives signal I MON and signal I TEST Read out the difference between the two. It has a function to output that difference as the CMOUT signal.

[0351] Signal I TEST This is input to the AD converter 100 via transistor M1. Signal I MON This is input to the AD converter 100. MON , I TEST teeth In addition to the current flowing from the external pixels to the AD converter 100, the AD converter 100 also It is also possible to handle the current flowing into external pixels.

[0352] The AD converter 100 converts the input analog signal to a digital signal, which is the signal OUT (signal). It has the function of converting to and outputting (OUT_1 to OUT_N).

[0353] Furthermore, circuit SR is a shift register, and one of the signals OUT_1 to OUT_N It has the function of selecting signals. Signal SP and signal SCLK shown in Figure 20 are These represent the pulse signal and clock signal input to the circuit SR, respectively.

[0354] Circuit SR outputs multiple signals SEL (SEL[1] to SEL[N]). Signal SE If one of the signals L[1] through SEL[N] reaches a High level (hereinafter referred to as H level) Then, the remaining N-1 signal becomes low level (L level). The signal SE becomes high level. L turns on transistor M1 and makes TRIBUF262 conduction. On the other hand, L When the signal level reaches SEL, it turns off transistor M1 and turns TRIBUF262 high. The impedance is set. Also, the AD converter 100 is set to operate according to the signal SEL. The system can be switched between active and idle states. In this way, the selected signal I is sent to the circuit SR. T EST The signal is input to the AD converter 100, and the selected signal OUT is sent to the circuit SR. It is output externally as CMOUT.

[0355] For example, consider the case where the signal SEL[1] is at a high level. In this case, transistor M1 A high-level potential is applied to the gate of [1], and transistor M1[1] turns on. On the other hand, an L-level potential is applied to the gates of transistors M1[2] to M1[N]. , transistors M1[2] to M1[N] turn off. As a result, transistor M1[ Only 1] is turned on, signal I TEST This is input to the AD converter 100[1]. Only the signal OUT_1 is output to the outside as the signal CMOUT. Thereafter, a plurality of signals By repeating the operation based on SEL, the signal I MON or the signal I TEST corresponding signal O UT can be output as the signal CMOUT.

[0356] Note that, in this embodiment, an example of handling 8-bit data is shown, but it is not limited thereto, and one aspect of the present invention can also handle data of arbitrary k bits (k is a natural number of 1 or more). It is possible.

[0357] In the AD conversion circuit 224, the transistor M1 is preferably an OS transistor with a small off-current. It is preferable.

[0358] In a display device including a transistor with a small pixel size and the light-emitting element described in FIGS. 18A to 18C, the current flowing through the light-emitting element is small, and correction within the pixel is difficult. In the AD conversion circuit including the semiconductor device which is one aspect of the present invention, it becomes possible to detect a minute current with high accuracy. Therefore, it is possible to perform highly accurate correction of the current flowing through the display element. In a display device including a transistor with a small pixel size and the light-emitting element described in FIGS. 18A to 18C, the current flowing through the light-emitting element is small, and correction within the pixel is difficult. In the AD conversion circuit including the semiconductor device which is one aspect of the present invention, it becomes possible to detect a minute current with high accuracy. Therefore, it is possible to perform highly accurate correction of the current flowing through the display element. In the AD conversion circuit including the semiconductor device which is one aspect of the present invention, it becomes possible to detect a minute current with high accuracy. Therefore, it is possible to perform highly accurate correction of the current flowing through the display element. For this reason, it is possible to perform highly accurate correction of the current flowing through the display element. It is possible.

[0359] <Configuration Example 2 of AD Conversion Circuit Having AD Conversion Device 100> FIG. 21 is a circuit diagram showing a configuration example of an AD conversion circuit 224 including the AD conversion device 100 described in Embodiment 1 having a different configuration from FIG. 20. The AD conversion circuit 224 includes a plurality of transistors M1 (M1[1] to M1[N], N is a natural number of 1 or more), an AD conversion device 10 0, and a circuit SR (shift register). In FIG. 21, the signal I 0 and the circuit SR (shift register).

[0360] In FIG. 21, the signal I MONThe signal is input to the AD converter 100 via transistor M1. Also, signal I TEST This is input to the AD converter 100.

[0361] The AD converter 100 converts the input analog signal into a digital signal, which is the signal CMOUT. It has the function to output.

[0362] Circuit SR outputs multiple signals SEL (SEL[1] to SEL[N]). Signal SE If one of the signals L[1] through SEL[N] reaches a High level (hereinafter referred to as H level) Then, the remaining N-1 signal becomes low level (L level). The signal SE becomes high level. L turns on transistor M1. Meanwhile, the signal SEL, which is at an L level, turns on the transistor Turn off the ZISTA M1. Also, the AD converter 100 will select one of the multiple signals SEL Depending on the situation, the circuit S can be switched between an operational state and a dormant state. The selected signal I is R. MON The signal is input to the AD converter 100 and selected by the circuit SR. The signal CMOUT is output externally.

[0363] For example, consider the case where the signal SEL[1] is at a high level. In this case, transistor M1 A high-level potential is applied to the gate of [1], and transistor M1[1] turns on. On the other hand, an L-level potential is applied to the gates of transistors M1[2] to M1[N]. , transistors M1[2] to M1[N] turn off. As a result, transistor M1[ Only 1] is turned on, signal I MON However, this is input to the AD converter 100, and the AD converter The signal CMOUT is output externally from 100. Subsequently, operation based on multiple signals SEL is performed. By repeating this process, signal I MON or signal I TEST Outputs a CMOUT signal corresponding to the output. It is possible.

[0364] By using this configuration, miniaturization or high integration can be achieved in a display device equipped with a semiconductor device. It can be measured.

[0365] This embodiment can be appropriately combined with other embodiments shown in this specification and elsewhere.

[0366] (Embodiment 5) In this embodiment, the transistor configuration applicable to the semiconductor device described in the above embodiment is Let's explain an example. As an example, transistors with different electrical characteristics are stacked together. The configuration will be explained. By adopting this configuration, the design flexibility of semiconductor devices can be increased. It is possible. Also, by stacking transistors with different electrical characteristics, a semiconductor device can be created. This can increase the density of data.

[0367] A portion of the cross-sectional structure of a semiconductor device is shown in Figure 22. The semiconductor device shown in Figure 22 is a transistor. It has 500, transistor 550, and capacitive element 600. Figure 22 shows the capacitive element Although the sub-element 600 is shown as a parallel plate type, the shape of the capacitive element 600 is not limited to this. The element 600 may be, for example, cylindrical in shape. Figure 23A shows the transistor 500. This is a top view. Figure 23B is a cross-sectional view of the area L1-L2 shown by the dashed line in Figure 23A. This is a cross-sectional view of transistor 500 in the channel length direction. Figure 23C is a cross-sectional view of Figure 23A. This is a cross-sectional view of the area W1-W2 indicated by the dashed line, showing the channel of transistor 500. This is a cross-sectional view in the width direction. For example, transistor 500 is the transistor shown in the above embodiment. OS transistors applicable to stylus, that is, transistors having an oxide semiconductor in the channel formation region. It corresponds to a transistor. Also, transistor 550 is the transistor shown in the above embodiment. Si transistors applicable to the ter, that is, transistors having silicon in the channel formation region It corresponds to a sta.

[0368] Transistor 500 is an OS transistor. OS transistors have extremely low off-currents. Therefore, the data voltage written to the memory node via transistor 500 is This allows for the retention of charge over a long period of time. In other words, the refresh frequency of the memory node By reducing the frequency or eliminating the need for refresh operations, the power consumption of semiconductor devices is reduced. It can be reduced.

[0369] In Figure 22, transistor 500 is located above transistor 550, and the capacitive element 60 0 is located above transistors 550 and 500.

[0370] The transistor 550 is mounted on the substrate 371. The substrate 371 is, for example, a p-type silicon The substrate is n-type silicon. Substrate 371 may also be an n-type silicon substrate. The oxide layer 374 is substrate 3 71 An insulating layer formed by burried oxide (BO The X layer (also called the X layer) is preferably made of silicon oxide, for example. Transistor 550 is based Single crystal silicon, so-called SOI (Sil), is provided on plate 371 via an oxide layer 374. (Icon On Insulator) Provided on the circuit board.

[0371] In the SOI substrate, the substrate 371 is provided with an insulator 373 that functions as an element isolation layer. The substrate 371 also has a well region 372. The well region 372 is a transistor 5 This is a region to which n-type or p-type conductivity is imparted according to 50 conductivity types. In single-crystal silicon, the semiconductor region 375 functions as either a source region or a drain region. Low-resistance regions 376a and 376b are provided. It has a low resistance region of 376c.

[0372] Transistor 550 is superimposed on a well region 372 to which impurity elements that impart conductivity have been added. It can be provided in a way that allows the potential to be independently controlled through the low-resistance region 376c. By changing it in this way, it can function as the bottom gate electrode of transistor 550. Yes, it is possible. Therefore, the threshold voltage of transistor 550 can be controlled. In particular, By applying a negative potential to well region 372, the threshold voltage of transistor 550 is determined. This makes it possible to increase the size and reduce the off-current. Therefore, well area 372 By applying a negative potential, the potential applied to the gate electrode of the Si transistor becomes 0V. The drain current can be reduced. As a result, the amplifier with transistor 550 This can reduce power consumption based on through-currents in calculation circuits and improve calculation efficiency. Cut.

[0373] The transistor 550 has an insulator 377 between the top surface of the semiconductor layer and the side surface in the channel width direction. It is preferable to have a so-called Fin type, which is covered with a conductor 378. By making the Ta550 a Fin type, the effective channel width is increased, thus transforming the transistor This can improve the ON characteristics of the ZISTA 550. Furthermore, it increases the contribution of the electric field of the gate electrode. This allows for improved off-peak characteristics of transistor 550.

[0374] Note that transistor 550 is a p-channel type transistor or an n-channel type transistor. Any of the Langista models will do.

[0375] Conductor 378 may function as the first gate (also called the top gate) electrode. Furthermore, the well region 372 is the second gate (also called the back gate or bottom gate) It may function as a pole. In that case, the potential applied to the well region 372 is the low-resistance region. It can be controlled via region 376c.

[0376] The region where the channel of the semiconductor region 375 is formed, the neighboring region, the source region, or The low-resistance region 376a and low-resistance region 376b, which are rain regions, and the well region 372 In low-resistance regions such as 376c connected to electrodes that control the potential, silicon-based semiconductors It is preferable that it contains any semiconductor, and preferably single-crystal silicon. Or Ge (Germanium), SiGe (Silicon Germanium), GaAs (Gallium Arsenide), G It may be formed from a material containing aAlAs (gallium aluminum arsenide), etc. A silicon-based structure in which the effective mass is controlled by applying stress and changing the lattice spacing, Alternatively, by using GaAs and GaAlAs, the transistor 550 can be made H It could also be called EMT.

[0377] Well region 372, low resistance region 376a, low resistance region 376b, and low resistance region 376 c is a semiconductor material applicable to semiconductor region 375, as well as n-type conductive materials such as arsenic and phosphorus. It contains elements that impart a certain property, or elements that impart p-type conductivity, such as boron.

[0378] The conductor 378, which functions as a gate electrode, is a component that imparts n-type conductivity, such as arsenic or phosphorus. Semiconductor materials such as silicon containing elements that impart p-type conductivity, such as boron or other elements. Conductive materials such as metallic materials, alloy materials, or metal oxide materials can be used. Furthermore, the conductor 378 may be a silicide such as nickel silicide.

[0379] Furthermore, since the work function is determined by the material of the conductor, by selecting the material of the conductor... This allows you to adjust the threshold voltage of the transistor. Specifically, titanium nitride is used as the conductor. It is preferable to use materials such as tannin and / or tantalum nitride. Furthermore, conductivity and filling To achieve both density and conductivity, metal materials such as tungsten and / or aluminum are used as conductors. It is preferable to use the material in a laminated form, and in particular, using tungsten is preferable in terms of heat resistance. It seems so.

[0380] Low-resistance region 376a, low-resistance region 376b, and low-resistance region 376c are made of another conductor. For example, a configuration in which silicides such as nickel silicide are laminated may be used. By doing so, the conductivity of the region that functions as an electrode can be increased. Also, at this time, The sides of the conductor 378 function as the gate electrode, and the insulating film function as the gate insulating film. On the sides of the body, an insulating layer that functions as a sidewall spacer (also called a sidewall insulating layer) is provided. This configuration may also be provided. With this configuration, the conductor 378 and the low-resistance region 376a This prevents the low-resistance region 376b from becoming conductive.

[0381] The transistor 550 is covered by insulators 379, 381, 383, and insulation The bodies 385 are arranged in a sequential stacking fashion.

[0382] As insulators 379, 381, 383, and 385, for example, oxidative Silicon, silicon oxide nitride, silicon nitride, silicon nitride, aluminum oxide, acid Aluminum nitride, aluminum nitride oxide, aluminum nitride, etc., can be used.

[0383] In this specification, "oxidative nitriding" refers to a process in which the composition contains more oxygen than nitrogen. It refers to a material with a large quantity, and "nitriding oxidation" means that, in terms of composition, it has a higher nitrogen content than oxygen. This shows the material. For example, in this specification, silicon oxidnitride is defined as having the following composition. This refers to a material with a higher oxygen content than nitrogen, and silicon nitride, in terms of its composition, is acid This indicates a material with a higher nitrogen content than the element itself.

[0384] The insulator 381 smooths out the step created by the transistor 550 and other components located below it. It may also function as a planarizing film that flattens. For example, the upper surface of the insulator 381 is flat To improve its flexibility, it is planarized using a planarization treatment such as chemical mechanical polishing (CMP). It's okay to be there.

[0385] Furthermore, the insulator 383 receives transistors from the substrate 371 or transistors 550, etc. A barrier film is provided in the region where Ta500 is installed, which prevents hydrogen and impurities from diffusing. It is preferable to use [this].

[0386] As an example of a film that has barrier properties against hydrogen, for example, silica nitride formed by CVD. A semiconductor having an oxide semiconductor such as transistor 500 can be used. The diffusion of hydrogen into the element may degrade the characteristics of the semiconductor element. Therefore, A film that suppresses hydrogen diffusion is used between transistor 500 and transistor 550. It is preferable to have one. Specifically, a membrane that suppresses hydrogen diffusion is one that minimizes hydrogen desorption. It will form a membrane.

[0387] The amount of hydrogen desorbed can be analyzed, for example, using a thermodynamic desorption gas analysis (TDS) method. For example, the amount of hydrogen desorption from insulator 383 is determined in TDS analysis when the film surface temperature is 5 In the range of 0°C to 500°C, the amount of desorption converted to hydrogen atoms is per unit area of ​​insulator 383. Convert to units, 10 x 10 15 atoms / cm 2 The following is preferably 5 × 10 15 at oms / cm 2 The following is acceptable.

[0388] Furthermore, it is preferable that the dielectric constant of insulator 385 is lower than that of insulator 383. For example, insulation The relative permittivity of body 385 is preferably less than 4, and more preferably less than 3. Also, for example, insulator 3 The relative permittivity of 85 is preferably 0.7 times or less the relative permittivity of the insulator 383, and preferably 0.6 times or less. More preferable. By using a material with a low dielectric constant as the interlayer film, parasitic capacitance between wirings can be reduced. It is possible.

[0389] Furthermore, insulators 379, 381, 383, and 385 contain capacitive elements 6 00, or conductors 328 and 330 connected to transistor 500 are embedded. It is included. Note that conductors 328 and 330 are used as plugs or wiring. It has a function. Also, a conductor that functions as a plug or wiring has multiple configurations. In some cases, the same symbol may be assigned to them. Also, in this specification, wiring and connections The connecting plug may be an integrated part. That is, a part of the conductor functions as wiring. In some cases, and sometimes even a portion of the conductor functions as a plug.

[0390] The materials for each plug and wiring (conductor 328, conductor 330, etc.) are metal materials, composite materials, etc. A conductive material such as gold material, metal nitride material, or metal oxide material is used in a single layer or in a multi-layered configuration. It can be used with tungsten or molybdenum, which offer both heat resistance and conductivity. It is preferable to use a high melting point material, and it is preferable to use tungsten. Alternatively, A It is preferable to form it with a low-resistance conductive material such as aluminum or copper. Low-resistance conductive material By using this material, the wiring resistance can be reduced.

[0391] A wiring layer may be provided on the insulator 385 and the conductor 330. For example, in Figure 22, Insulators 350, 352, and 354 are arranged in a sequential stack. Insulators 350, 352, and 354 have a conductor 356 formed on them. The conductor 356 functions as a plug or wire connecting to the transistor 550. It possesses. Furthermore, the conductor 356 is made of the same material as the conductors 328 and 330. It can be established.

[0392] For example, insulator 350 has a barrier property against hydrogen, similar to insulator 383. It is preferable to use an insulator. Furthermore, the conductor 356 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 350 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 550 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 550 to transistor 500.

[0393] For example, tantalum nitride can be used as a conductor that has barrier properties against hydrogen. This is good. Also, by laminating tantalum nitride and highly conductive tungsten, the wiring can be This allows for the suppression of hydrogen diffusion from transistor 550 while maintaining conductivity. In this case, the tantalum nitride layer having barrier properties against hydrogen provides a barrier against hydrogen. It is preferable that the configuration is in contact with the insulator 350.

[0394] A wiring layer may be provided on the insulator 354 and the conductor 356. For example, in Figure 22, Insulators 360, 362, and 364 are arranged in a sequential stack. Conductors 366 are formed on insulators 360, 362, and 364. The conductor 366 functions as a plug or wiring. It can be provided using the same material as the electric element 328 and the conductor 330.

[0395] For example, insulator 360 has barrier properties against hydrogen, similar to insulator 383. It is preferable to use an insulator. Furthermore, the conductor 366 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 360 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 550 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 550 to transistor 500.

[0396] A wiring layer may be provided on the insulator 364 and the conductor 366. For example, in Figure 22, Insulators 370, 369, and 368 are arranged in a sequential stack. Insulators 370, 369, and 368 have a conductive material 376 formed on them. The conductor 376 functions as a plug or wiring. It can be provided using the same material as the electric element 328 and the conductor 330.

[0397] For example, insulator 370 has a barrier property against hydrogen, similar to insulator 383. It is preferable to use an insulator. Furthermore, the conductor 376 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 370 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 550 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 550 to transistor 500.

[0398] A wiring layer may be provided on the insulator 368 and the conductor 376. For example, in Figure 22, Insulators 380, 382, ​​and 384 are arranged in a sequential stack. Conductors 386 are formed on insulators 380, 382, ​​and 384. Conductor 386 functions as a plug or wiring. It can be provided using the same material as the electric element 328 and the conductor 330.

[0399] For example, insulator 380 has a barrier property against hydrogen, similar to insulator 383. It is preferable to use an insulator. Furthermore, the conductor 386 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 380 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 550 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 550 to transistor 500.

[0400] In the above, a wiring layer containing a conductor 356, a wiring layer containing a conductor 366, and a conductor 376 Although the wiring layer including the conductive 386 has been described, this embodiment is not applicable. The semiconductor device is not limited to this. A wiring layer similar to a wiring layer containing conductor 356 The number of layers may be three or less, or the wiring layers similar to the wiring layer containing the conductor 356 may be made five or more layers. That's good too.

[0401] Insulator 384 has insulators 510, 512, 514, and 516. They are arranged in a stack in order. Insulator 510, insulator 512, insulator 514, and insulating It is preferable that one of the surrounding members 516 be made of a material that has barrier properties against oxygen and hydrogen. It seems so.

[0402] For example, the insulator 510 and the insulator 514 have, for example, a substrate 371 or a transient From the area where transistor 550 is installed, to the area where transistor 500 is installed, hydrogen and impurities It is preferable to use a film that has barrier properties against materials. Therefore, the same as insulator 383. You can use the materials provided by [name / company].

[0403] As an example of a film with hydrogen barrier properties, silicon nitride formed by CVD is used. This can be done. Here, a semiconductor device having an oxide semiconductor such as transistor 500, Hydrogen diffusion can degrade the properties of the semiconductor device. Therefore, A film that suppresses hydrogen diffusion is used between the transistor 500 and the transistor 550. It is preferable.

[0404] Furthermore, as films having barrier properties against hydrogen, for example, insulator 510 and insulator 5 14 uses metal oxides such as aluminum oxide, hafnium oxide, and tantalum oxide. It is preferable.

[0405] In particular, aluminum oxide is a source of oxygen and hydrogen, which can cause variations in the electrical properties of transistors. It has a high barrier effect that prevents both water and other impurities from passing through the film. Aluminum oxide is susceptible to hydrogen, moisture, and other elements during and after the transistor fabrication process. This prevents impurities from entering transistor 500. This can suppress the release of oxygen from the oxides that make up the transistor. It is suitable for use as a protective film against 500.

[0406] Furthermore, for example, the same material as the insulator 379 is used for insulators 512 and 516. It is possible to do so by applying materials with relatively low dielectric constants to these insulators. This can reduce parasitic capacitance between wirings. For example, insulator 512 and insulation As body 516, a silicon oxide film or a silicon oxide nitride film can be used.

[0407] Furthermore, insulators 510, 512, 514, and 516 contain a conductor 5 18, and a conductor (e.g., conductor 503) that constitutes the transistor 500 is embedded. It is built in. The conductor 518 is connected to the capacitive element 600 or the transistor 550. It has the function of a plug or wiring. Conductor 518 is connected to conductor 328, and It can be provided using the same material as the conductor 330.

[0408] In particular, the conductor 518 in the region in contact with the insulator 510 and the insulator 514 is oxygen, hydrogen, And preferably it is a conductor that has barrier properties against water. With this configuration, Transistor 550 and Transistor 500 have barrier properties against oxygen, hydrogen, and water. In the layer, it can be separated, and hydrogen from transistor 550 to transistor 500 It can suppress diffusion.

[0409] A transistor 500 is provided above the insulator 516.

[0410] As shown in Figures 23A to 23C, transistor 500 is an insulator 514 and an insulator A conductor 503 is positioned to be embedded in 516, and the insulator 516 and conductor 50 An insulator 520 placed on top of 3, an insulator 522 placed on top of insulator 520, and An insulator 524 placed on the edge 522, and an oxide 53 placed on the insulator 524 0a, oxide 530b placed on oxide 530a, and on oxide 530b, Conductors 542a and 542b are positioned separately, and conductor 542a and conductor It is positioned on 542b and superimposed between the conductor 542a and the conductor 542b to form an opening. The insulator 580, the insulator 545 positioned on the bottom and sides of the opening, and the insulator 545 It has a conductor 560 arranged on the forming surface.

[0411] Furthermore, as shown in Figures 23B and 23C, oxide 530a, oxide 530b, conductor The insulator 544 is placed between the conductor 542a and conductor 542b and the insulator 580. This is preferable. Also, as shown in Figures 23A to 23C, the conductor 560 is an insulator 545 A conductor 560a is provided on the inside of the conductor 560a, and is provided so as to be embedded inside the conductor 560a. It is preferable to have a conductive material 560b. Also, as shown in Figures 23B and 23C In this manner, an insulator 574 is placed on top of the insulator 580, the conductor 560, and the insulator 545. It is preferable that this be done.

[0412] In this specification, oxide 530a and oxide 530b are collectively referred to as oxides. There are cases where it is 530.

[0413] Furthermore, in transistor 500, oxidation occurs in the region where the channel is formed and in its vicinity. The present invention describes a configuration in which two layers, material 530a and oxide 530b, are laminated. This is not limited to the above. For example, a single layer or a laminate of three or more layers of oxide 530b. It is also acceptable to use a configuration that includes a set of components.

[0414] Furthermore, in transistor 500, the conductor 560 is shown as a two-layer stacked structure, The invention is not limited thereto. For example, the conductor 560 may have a single-layer configuration. Furthermore, a laminated structure of three or more layers is also possible. Also, as shown in Figures 22 and 23A to 23C Transistor 500 is just one example, and is not limited to its configuration; circuit configuration and driving method may also be used. Use the appropriate transistor depending on the situation.

[0415] Here, conductor 560 functions as the gate electrode of transistor 500, and conductor 542 a and conductor 542b function as the source electrode or drain electrode, respectively. As noted, the conductor 560 is connected to the opening of the insulator 580, and to the conductor 542a and the conductor 54 It is formed so as to be embedded in the region sandwiched between 2b. Conductor 560, Conductor 542a The arrangement of the conductor 542b is selected in a self-aligned manner with respect to the opening of the insulator 580. In other words, in transistor 500, the gate electrode is placed between the source electrode and the drain electrode. Therefore, the conductor 560 can be positioned with a margin for alignment. Since it can be formed without providing a component, the occupied area of ​​the transistor 500 is reduced. This makes it possible to miniaturize and highly integrate semiconductor devices.

[0416] Furthermore, the conductor 560 is formed in a self-aligned manner in the region between conductor 542a and conductor 542b. Therefore, the conductor 560 has a region that overlaps with conductor 542a or conductor 542b. It does not have. As a result, a shape is formed between the conductor 560 and the conductors 542a and 542b. The resulting parasitic capacitance can be reduced. Therefore, the switching of transistor 500 This allows for increased speed and improved frequency response.

[0417] The conductor 560 functions as the first gate (also called the gate or top gate) electrode. In some cases, the conductor 503 is the second gate (also known as the back gate or bottom gate). It may function as an electrode. In that case, the potential applied to the conductor 503 is the conductive By changing the potential applied to body 560 independently, without being linked to it, transistor 50 The threshold voltage of 0 can be controlled. In particular, by applying a negative potential to the conductor 503... This increases the threshold voltage of transistor 500 and reduces the off-current. This becomes possible. Therefore, applying a negative potential to the conductor 503 is preferable to not applying one. This allows us to reduce the drain current when the potential applied to the conductor 560 is 0V. Cut.

[0418] The conductor 503 is positioned to overlap with the oxide 530 and the conductor 560. Therefore, when a potential is applied to the conductor 560 and the conductor 503, the conductor 560 generates The electric field generated by the conductor 503 connects with the electric field generated by the conductor 503, forming a chain in the oxide 530. It can cover the flannel formation area.

[0419] In this specification, etc., a pair of gate electrodes (a first gate electrode and a second gate electrode) The electric field electrically surrounds the channel formation region, creating a transistor configuration that is surr This is called an sounded channel (S-channel) configuration. Also, in this specification, etc. The disclosed S-channel configuration differs from the Fin-type configuration and the Planar-type configuration. -By adopting a channel configuration, resistance to short-channel effects is increased, in other words... This makes it possible to create a transistor that is less prone to short-channel effects.

[0420] Furthermore, the conductor 503 has the same configuration as the conductor 518, and the insulators 514 and 5 A conductor 503a is formed in contact with the inner wall of the 16 openings, and a conductor 503b is formed further inside. This has been done. Furthermore, in transistor 500, conductors 503a and 503b are used. Although the present invention describes a stacked configuration, it is not limited thereto. For example, The electrical body 503 may be provided as a single layer or as a laminated structure of three or more layers.

[0421] Here, the conductor 503a allows for the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, and copper atoms. It is preferable to use a conductive material that has a suppressive function (i.e., the above-mentioned impurities are less likely to permeate it). i. Or, inhibit the diffusion of oxygen (for example, at least one such as an oxygen atom or oxygen molecule). It is preferable to use a conductive material that has a functional property (i.e., one that is impermeable to the above-mentioned oxygen). In this specification, the function of suppressing the diffusion of impurities or oxygen means the above-mentioned impurities or The function is to suppress the diffusion of any one or all of the above-mentioned oxygen species.

[0422] For example, conductor 503a has the function of suppressing oxygen diffusion, so conductor 503b This can suppress the oxidation that causes a decrease in conductivity.

[0423] Furthermore, if the conductor 503 also functions as wiring, the conductor 503b may be tungsten, copper, Alternatively, it is preferable to use a highly conductive material, mainly composed of aluminum. In this embodiment, the conductor 503 is shown as a laminate of conductor 503a and conductor 503b. However, the conductor 503 may have a single-layer configuration.

[0424] Insulators 520, 522, and 524 function as a second gate insulating film. It has.

[0425] Here, the insulator 524 in contact with the oxide 530 is more than the oxygen that satisfies the stoichiometric composition. It is preferable to use an insulator containing oxygen. This oxygen is released from the film upon heating. It is inexpensive. In this specification, the oxygen released by heating may be referred to as "excess oxygen." In other words, the insulator 524 has a region containing excess oxygen (also called the "excess oxygen region"). It is preferable that such an insulator containing excess oxygen is brought into contact with oxide 530. By providing this, oxygen deficiency (V) in oxide 530 is reduced. O :oxygen vacancy and This reduces (also known as) oxidation and improves the reliability of transistor 500. If hydrogen enters the oxygen vacancy in substance 530, the defect (hereinafter referred to as V) O It is sometimes referred to as H. ) can function as a donor, and electrons, which are carriers, can be generated. Also, one of the hydrogen atoms In some cases, the part combines with oxygen, which is bonded to the metal atom, to generate electrons, which are carriers. Therefore, transistors using oxide semiconductors that contain a large amount of hydrogen are normally-on type. It is prone to becoming a sex. Also, hydrogen in oxide semiconductors moves due to stress such as heat and electric fields. Because it is easy to do so, if oxide semiconductors contain a lot of hydrogen, the reliability of the transistor deteriorates. There is also a risk. In one embodiment of the present invention, V in oxide 530 O Reduce H as much as possible, It is preferable to make it highly pure or substantially highly pure. Thus, V O H is sufficient To obtain an oxide semiconductor with reduced impurities, it is necessary to remove water, hydrogen, and other impurities from the oxide semiconductor. This involves (also called "dehydration" or "dehydrogenation") supplying oxygen to the oxide semiconductor. It is important to compensate for the oxygen deficiency (also called "oxygenation treatment"). O H etc. Using oxide semiconductors with sufficiently reduced impurities in the channel formation region of transistors. This allows for the provision of stable electrical characteristics.

[0426] As an insulator having an excess oxygen region, specifically, an oxidative material in which some oxygen is removed by heating. It is preferable to use a material. Oxides that desorb oxygen upon heating include TDS (The In rmal desorption spectroscopy analysis, oxygen atoms were converted... The calculated amount of oxygen desorption is 1.0 × 10⁻⁶. 18 atoms / cm 3 The above, preferably 1.0× 10 19 atoms / cm 3 More preferably 2.0 × 10 19 atoms / cm 3 Above, or 3.0 × 10 20 atoms / cm 3 The above describes the oxide film. The surface temperature of the film during the above TDS analysis is between 100°C and 700°C, or 10 A temperature range of 0°C to 400°C is preferred.

[0427] Furthermore, the insulator having the above excess oxygen region and oxide 530 are brought into contact and heat treated, microphone One or more of the following processes may be performed: low-wave processing or RF processing. By doing so, water or hydrogen can be removed from oxide 530. For example, oxide 5 At 30, a reaction occurs in which the VoH bond is broken, or in other words, "V O H→Vo+H The following reaction occurs, allowing for dehydrogenation. Some of the hydrogen produced at this time is acid It combines with an element to form H2O, and is removed from oxide 530 or the insulator near oxide 530. In some cases, this may occur. Also, some of the hydrogen is absorbed by conductors 542a and 542b. It may be done.

[0428] Furthermore, the above microwave processing is performed using, for example, a device having a power supply that generates high-density plasma. Alternatively, it is preferable to use a device that has a power supply that applies RF to the substrate side. For example, oxygen By using a gas containing and a high-density plasma, high-density oxygen radicals are generated. This allows for the application of RF to the substrate side, and the acid generated by the high-density plasma can be used. The purpose is to efficiently introduce elementary radicals into oxide 530 or an insulator near oxide 530. This can be done. Furthermore, the above microwave treatment is performed at a pressure of 133 Pa or higher, preferably 200 Pa. The Pa should be a or higher, more preferably 400 Pa or higher. For example, oxygen and argon are used as the gases introduced into the chamber, with an oxygen flow rate ratio (O2 / The (O2+Ar) content should be 50% or less, preferably between 10% and 30%.

[0429] Furthermore, during the manufacturing process of transistor 500, the surface of oxide 530 is exposed. Heat treatment is preferable. This heat treatment may be performed at temperatures of 100°C to 450°C, More preferably, the process should be carried out at a temperature between 350°C and 400°C. Note that the heat treatment may also involve the use of nitrogen gas. Alternatively, an inert gas atmosphere, or an oxidizing gas at 10 ppm or more, 1% or more, or 1 The procedure should be carried out in an atmosphere containing 0% or more of the substance. For example, heat treatment is preferably carried out in an oxygen atmosphere. This supplies oxygen to oxide 530, thereby eliminating oxygen deficiency (VO This can help reduce ) Furthermore, the heat treatment may be carried out under reduced pressure. Alternatively, the heat treatment may be carried out using nitrogen gas or an inert gas. After heat treatment in an atmosphere of oxidizing gas, 10 pp of oxidizing gas is added to replenish the desorbed oxygen. The procedure may be carried out in an atmosphere containing m or more, 1% or more, or 10% or more. Alternatively, an oxidizing gas may be used. After heat treatment in an atmosphere containing 10 ppm or more, 1% or more, or 10% or more, then continuously Heat treatment may be carried out in a nitrogen gas or inert gas atmosphere.

[0430] Furthermore, by performing an oxygenation treatment on oxide 530, the oxygen deficiencies in oxide 530 are supplied. The oxygen used for repair, or in other words, the reaction "Vo + O → null" is promoted. This is possible. Furthermore, the oxygen supplied reacts with the hydrogen remaining in the oxide 530. Then, the hydrogen can be removed as H2O (dehydrated). This removes the oxide. The hydrogen remaining in 530 recombines with the oxygen vacancy and V O This inhibits the formation of H. It is possible.

[0431] Furthermore, if the insulator 524 has an excess oxygen region, the insulator 522 will have oxygen (for example, acid It has the function of suppressing the diffusion of elementary atoms, oxygen molecules, etc. (meaning that the above-mentioned oxygen does not easily permeate it). It is preferable.

[0432] The insulator 522 has the function of suppressing the diffusion of oxygen and impurities, thereby preventing the oxide 530 The oxygen contained in does not diffuse toward the insulator 520, which is preferable. Also, conductor 503 However, it is possible to suppress the reaction of the insulator 524 and oxide 530 with oxygen. ru.

[0433] Insulator 522 is, for example, aluminum oxide, hafnium oxide, aluminum and haf Oxides containing nium (hafnium aluminate), tantalum oxide, zirconium oxide, Lead zirconate tane (PZT), strontium titanate (SrTiO3), or (B An insulator containing so-called high-k materials such as a,Sr)TiO3(BST) in a single layer or It is preferable to use them in a stacked configuration. As transistors become smaller and more integrated, Thinning the gate insulating film can sometimes lead to problems such as leakage current. By using a high-k material as an insulator that functions in this way, the physical film thickness is maintained while transient This allows for a reduction in gate potential during startup.

[0434] In particular, it has the function of suppressing the diffusion of impurities and oxygen (the above oxygen does not easily permeate). ) An insulator containing an oxide of either aluminum or hafnium, or both, which are insulating materials. It is recommended to use it as an insulator containing an oxide of either aluminum or hafnium, or both. , aluminum oxide, hafnium oxide, aluminum and hafnium oxide ( It is preferable to use materials such as humic aluminate. When 22 is formed, the insulator 522 releases oxygen from the oxide 530, and also transforms As a layer to suppress the incorporation of impurities such as hydrogen from the peripheral area of ​​Zista 500 into the oxide 530, To be able to.

[0435] Alternatively, these insulators may contain, for example, aluminum oxide, bismuth oxide, germanium oxide. M, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, acid Zirconium oxide may be added. Alternatively, these insulators may be nitrided. Silicon oxide, silicon oxide-nitride, or silicon nitride may be used as an insulator in a laminated form.

[0436] Furthermore, it is preferable that the insulator 520 is thermally stable. For example, silicon oxide and Silicon oxide nitride is suitable because it is thermally stable. Also, high-k material By combining the insulator with silicon oxide or silicon oxide nitride, thermal stability and An insulator 520 with a high dielectric constant and a multilayer structure can be obtained.

[0437] Furthermore, in the transistor 500 shown in Figures 23A to 23C, the second is a stacked structure consisting of three layers. Insulators 520, 522, and 524 are shown as gate insulating films. However, the second gate insulating film may have a single layer, two layers, or a stacked structure of four or more layers. In that case, the laminated structure is not limited to one made of the same material, but is not limited to one made of different materials. That's good too.

[0438] The transistor 500 is formed in the oxide 530 including the channel formation region as an oxide semiconductor. A metal oxide capable of performing the function is used. For example, as oxide 530, In-M-Zn oxide (element M stands for aluminum, gallium, yttrium, tin, copper, vanadium, beryllium, and boron. Element, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium Choose from materials such as um, neodymium, hafnium, tantalum, tungsten, or magnesium. It is best to use one or more types of metal oxides.

[0439] The formation of metal oxides that function as oxide semiconductors may be carried out by sputtering. Alternatively, the ALD (Atomic Layer Deposition) method may be used. Regarding metal oxides that function as oxide semiconductors, they will be described in detail in other embodiments. ru.

[0440] Furthermore, the metal oxide that functions as a channel-forming region in oxide 530 is bandgable A metal oxide with a top voltage of preferably 2 eV or higher, and more preferably 2.5 eV or higher, is used. This is preferable. By using a metal oxide with a large band gap in this way, transient This can reduce the off-current of the sta.

[0441] Oxide 530 has oxide 530a beneath oxide 530b, so oxide 530a Furthermore, it is possible to suppress the diffusion of impurities from the components formed below to oxide 530b. Cut.

[0442] Furthermore, oxide 530 has a layered structure of multiple oxide layers with different atomic ratios of each metal atom. It is preferable that the metal oxide used in oxide 530a contains constituent elements The atomic ratio of element M in the oxide is the element of the constituent elements in the metal oxide used in oxide 530b. It is preferable that the ratio is greater than the atomic ratio of element M. Also, the metal oxide used in oxide 530a In this case, the atomic ratio of element M to In is in the metal oxide used in oxide 530b. Furthermore, it is preferable that the atomic ratio of element M to In is greater than that of In. Also, in oxide 530b In the metal oxide used, the atomic ratio of In to element M is used in oxide 530a. It is preferable that the atomic ratio of In to element M in the metal oxide is greater than that of In.

[0443] Furthermore, the energy at the lower end of the conduction band of oxide 530a is equal to the energy at the lower end of the conduction band of oxide 530b. It is preferable that the energy is higher than the electron affinity of oxide 530a. In other words, the electron affinity of oxide 530a is preferable. It is preferable that the electron affinity is smaller than that of oxide 530b.

[0444] Here, at the junction of oxide 530a and oxide 530b, the energy at the lower end of the conduction band - The energy levels change smoothly. In other words, the junction of oxide 530a and oxide 530b. The energy levels at the lower end of the conduction band in this region can be said to change continuously or form a continuous junction. This can be done. In order to do this, at the interface between oxide 530a and oxide 530b It is desirable to lower the defect level density of the mixed layer formed.

[0445] Specifically, oxides 530a and 530b have a common element other than oxygen (main component) By (using a fraction of a certain amount), a mixed layer with a low defect level density can be formed. For example, oxide If 530b is an In-Ga-Zn oxide, then the oxide 530a is an In-Ga-Zn acid It is advisable to use gallium oxides, Ga-Zn oxides, or other similar materials.

[0446] In this case, the main carrier pathway is oxide 530b. Oxide 530a is configured as described above. By doing so, the defect level density at the interface between oxide 530a and oxide 530b is reduced. This allows for reduced influence of interfacial scattering on carrier conduction, and The ZISTA 500 can achieve high on-current.

[0447] On the oxide 530b, there is a conductor 542a that functions as a source electrode and a drain electrode. , and a conductor 542b are provided. Conductors 542a and 542b are Aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium Um, beryllium, indium, ruthenium, iridium, strontium, lanthanum? A selected metal element, or an alloy containing the above-mentioned metal elements, or the above-mentioned metal elements It is preferable to use a combination of alloys, etc. For example, tantalum nitride, titanium nitride, tan Gusten, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, Ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum It is preferable to use oxides containing nickel. Also, tantalum nitride and titanium nitride are preferable. , nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, lutein oxide nium, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel Oxides containing ions are conductive materials that are resistant to oxidation, or maintain their conductivity even when absorbing oxygen. It is preferable because it is a material that can withstand hydrogen or acid. Furthermore, metal nitride films such as tantalum nitride can withstand hydrogen or acid. It is preferable because it has barrier properties against the element.

[0448] Furthermore, in Figure 23B, the conductors 542a and 542b are shown as single-layer structures. A laminated structure of two or more layers is also possible. For example, a tantalum nitride film and a tungsten film can be laminated. It is good to do so. Alternatively, a titanium film and an aluminum film may be laminated. Also, on a tungsten film A two-layer structure with an aluminum film laminated on top, and a copper film on top of a copper-magnesium-aluminum alloy film. A two-layer structure in which a copper film is laminated on a titanium film, a two-layer structure in which a copper film is laminated on a tungsten film A two-layer structure with stacked layers is also possible.

[0449] Furthermore, a titanium film or titanium nitride film, and an aluminum film layered on top of the titanium film or titanium nitride film. A titanium film or copper film is laminated, and then a titanium film or titanium nitride film is formed on top of it. Three-layer structure, molybdenum film or molybdenum nitride film, and the molybdenum film or molybdenum nitride An aluminum film or copper film is laminated on top of the molybdenum film, and then a molybdenum film is placed on top of that. This includes a three-layer structure that forms a molybdenum nitride film. Furthermore, indium oxide, tin oxide, or A transparent conductive material containing zinc oxide may also be used.

[0450] Furthermore, as shown in Figure 23B, the oxide 530 and the conductor 542a (conductor 542b) Regions 543a and 543b are formed at and near the interface as low-resistance regions. In some cases, region 543a may function as either the source region or the drain region. Region 543b can function as either the source region or the drain region. A channel-forming region is formed in the area sandwiched between region 543a and region 543b.

[0451] By providing the conductor 542a (conductor 542b) in contact with the oxide 530, The oxygen concentration in region 543a (region 543b) may decrease. Also, region 543a (region In region 543b), the metal contained in conductor 542a (conductor 542b) and the oxide 530 A metal compound layer containing the component may be formed. In such cases, region 543a (region The carrier density in region 543b increases, and region 543a (region 543b) becomes a low-resistance region. ru.

[0452] The insulator 544 is provided so as to cover the conductors 542a and 542b, and the conductor The oxidation of 542a and conductor 542b is suppressed. At this time, the insulator 544 is oxide It may be provided to cover the side of 530 and to be in contact with the insulator 524.

[0453] Insulator 544 includes hafnium, aluminum, gallium, yttrium, and zirconium. Tungsten, titanium, tantalum, nickel, germanium, neodymium, lanthanum Alternatively, a metal oxide containing one or more metals selected from magnesium, etc., may be used. It is possible to use silicon nitride or silicon nitride as the insulator 544. It can also be used.

[0454] In particular, as insulator 544, an oxide of either aluminum or hafnium, or both. Insulators containing aluminum oxide, hafnium oxide, aluminum, and hafnium It is preferable to use an oxide containing um (hafnium aluminate), etc. In particular, haf Aluminium aluminate has higher heat resistance than hafnium oxide film. Therefore, in subsequent processes... In heat treatment, it is preferable because it does not easily crystallize. Note that conductor 542a and conductor 542b is a material that is oxidation-resistant, or whose conductivity does not significantly decrease even when it absorbs oxygen. If it is a material, insulator 544 is not an essential component. Depending on the desired transistor characteristics... It can be designed as appropriate.

[0455] By including the insulator 544, water and impurities such as hydrogen contained in the insulator 580 become acidic. This can suppress the diffusion phenomenon into the ion 530b. Also, it can suppress the excess oxygen present in the insulator 580. This can suppress the oxidation of the conductor 542 (conductors 542a and 542b).

[0456] The insulator 545 functions as the first gate insulating film. The insulator 545 is the insulator described above. Similar to 524, an insulator containing excess oxygen and releasing oxygen upon heating is used to form It is preferable to do so.

[0457] Specifically, silicon oxide, silicon oxide nitride, silicon nitride oxide, and silicon oxide containing excess oxygen. Silicon oxide, silicon oxide with added fluorine, silicon oxide with added carbon, carbon, and Silicon oxide with added nitrogen and silicon oxide with voids can be used. Silicon oxide and silicon oxide-nitride are preferred because they are stable to heat.

[0458] By providing an insulator containing excess oxygen as insulator 545, oxidation occurs from insulator 545. Oxygen can be effectively supplied to the channel-forming region of material 530b. Also, insulator 5 Similar to 24, the concentration of impurities such as water or hydrogen in the insulator 545 has been reduced. Preferably, the film thickness of the insulator 545 is 1 nm or more and 20 nm or less. Also, The microwave treatment described above may be performed before and / or after the formation of the insulator 545. stomach.

[0459] Furthermore, in order to efficiently supply excess oxygen from the insulator 545 to the oxide 530, A metal oxide may be provided between the body 545 and the conductor 560. The metal oxide is an insulator. It is preferable to suppress oxygen diffusion from 545 to the conductor 560. By providing a metal oxide, the diffusion of excess oxygen from the insulator 545 to the conductor 560 is suppressed. This means that the decrease in the amount of excess oxygen supplied to oxide 530 can be suppressed. This can suppress the oxidation of the conductor 560 due to excess oxygen. The metal oxide in question is Any material suitable for use as an insulator 544 may be used.

[0460] Furthermore, the insulator 545 may be in a laminated configuration, similar to the second gate insulating film. As the miniaturization and integration of the grid progresses, the thinning of the gate insulating film leads to leakage current, etc. Because problems may occur, the insulator that functions as the gate insulating film is made of high-k material. By creating a laminated structure of a material and a thermally stable material, the physical film thickness is maintained while preventing traction. This allows for a reduction in gate potential during inverter operation. Furthermore, it offers thermal stability and a high dielectric constant. It can be configured as a laminated structure.

[0461] The conductor 560, which functions as the first gate electrode, has a two-layer configuration in Figures 23B and 23C. Although it is shown as such, it may be a single-layer structure or a laminated structure of three or more layers.

[0462] Conductor 560a contains hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and nitrogen oxide molecules. Conductive properties that suppress the diffusion of impurities such as N2O, NO, NO2, and copper atoms. It is preferable to use a material. Alternatively, oxygen (for example, oxygen atoms, oxygen molecules, etc.) It is preferable to use a conductive material that has the function of suppressing the diffusion of (1). Conductor 56 Because 0a has the function of suppressing oxygen diffusion, the oxygen contained in the insulator 545 This can suppress the oxidation of the conductor 560b and the resulting decrease in conductivity. Oxygen diffusion Examples of conductive materials that have the function of suppressing this include tantalum, tantalum nitride, and ruthenium. It is preferable to use um or ruthenium oxide. Also, as conductor 560a In that case, an oxide semiconductor applicable to oxide 530 can be used. By depositing 0b using the sputtering method, the electrical resistance of the conductor 560a is reduced. It can be made into an electrostatic material. This is called an OC (Oxide Conductor) electrode. It is possible.

[0463] Furthermore, the conductive material 560b is a conductive material whose main components are tungsten, copper, or aluminum. It is preferable to use the material. Also, since the conductor 560b also functions as wiring, It is preferable to use a highly conductive material. For example, tungsten, copper, or aluminum. A conductive material with um as its main component can be used. In addition, the conductor 560b has a laminated structure. This may also be the case, for example, as a laminated structure of titanium or titanium nitride and the above conductive material. good.

[0464] The insulator 580 is provided on the conductors 542a and 542b via the insulator 544. It is possible. The insulator 580 preferably has an excess oxygen region. For example, insulator 58 As 0, silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, fluorine Silicon oxide with added carbon, silicon oxide with added carbon, carbon, and nitrogen-added acid It is preferable to have silicon dioxide, porous silicon oxide, or a resin. Silicon oxide and silicon oxide-nitride are preferred because they are thermally stable. In particular, acid Silicon oxide and porous silicon oxide readily form excess oxygen regions in subsequent processes. This is preferable because it allows for this.

[0465] The insulator 580 preferably has an excess oxygen region. By providing the edge 580, oxygen in the insulator 580 is efficiently supplied to the oxide 530. This is possible. Furthermore, the concentration of impurities such as water or hydrogen in the insulator 580 has been reduced. It is preferable.

[0466] The opening in the insulator 580 is formed superimposed on the region between the conductor 542a and the conductor 542b. As a result, the conductor 560 has an opening in the insulator 580, and the conductor 542a and the conductor It is formed in a way that it is embedded in the region sandwiched between 542b.

[0467] When miniaturizing semiconductor devices, it is necessary to shorten the gate length, but the conductor 56 It is necessary to prevent the conductivity of 0 from decreasing. To achieve this, the film thickness of conductor 560 is increased. As a result, the conductor 560 may have a shape with a high aspect ratio. In this embodiment, the conductor Since 560 is to be embedded in the opening of the insulator 580, the conductor 560 has an aspect ratio Even with a highly shaped form, the conductive material 560 can be formed without collapsing during the process. ru.

[0468] The insulator 574 is located on the upper surface of the insulator 580, the upper surface of the conductor 560, and the upper surface of the insulator 545. It is preferable that it be provided in contact with the insulator 574. This allows for the creation of excess oxygen regions in insulators 545 and 580. Therefore, oxygen can be supplied to the oxide 530 from the excess oxygen region.

[0469] For example, as insulator 574, hafnium, aluminum, gallium, yttrium, and Titanium, tungsten, titanium, tantalum, nickel, germanium, or magnesium Metal oxides containing one or more selected metals, such as cium, can be used. ru.

[0470] In particular, aluminum oxide has high barrier properties, and in thin films of 0.5 nm to 3.0 nm... However, the diffusion of hydrogen and nitrogen can be suppressed. Therefore, the sputtering method The aluminum oxide film formed using this method serves as both an oxygen source and a barrier against impurities such as hydrogen. It can also function as a membrane.

[0471] Furthermore, it is preferable to provide an insulator 581 that functions as an interlayer film on top of the insulator 574. Insulator 581, like insulator 524, has an impurity concentration of water or hydrogen in the film. It is preferable that it be reduced.

[0472] Furthermore, openings formed in insulators 581, 574, 580, and 544 Conductors 540a and 540b are placed in the opening. Conductors 540a and conductors 540b is provided opposite the conductor 560, with the conductor 540a in between. b has the same configuration as conductors 546 and 548, which will be described later.

[0473] An insulator 582 is provided on the insulator 581. The insulator 582 is made of oxygen and hydrogen It is preferable to use a barrier material against it. Therefore, the insulator 582 is The same material as insulator 514 can be used. For example, insulator 582 may be aluminum oxide It is preferable to use metal oxides such as nium, hafnium oxide, and tantalum oxide.

[0474] In particular, aluminum oxide is a source of oxygen and hydrogen, which can cause variations in the electrical properties of transistors. It has a high barrier effect that prevents both water and other impurities from passing through the film. Aluminum oxide is susceptible to hydrogen, moisture, and other elements during and after the transistor fabrication process. This prevents impurities from entering transistor 500. This can suppress the release of oxygen from the oxides that make up the transistor. It is suitable for use as a protective film against 500.

[0475] Furthermore, an insulator 586 is provided on the insulator 582. The insulator 586 is insulator 3 Similar materials to those used in 79 can be used. Furthermore, these insulators have a relatively low dielectric constant. By applying certain materials, parasitic capacitance between wires can be reduced. For example, insulation As component 586, a silicon oxide film or a silicon oxide-nitride film can be used.

[0476] Also, insulator 520, insulator 522, insulator 524, insulator 544, insulator 580, insulation Body 574, insulator 581, insulator 582, and insulator 586 are connected to conductor 546, and Conductors such as 548 are embedded within.

[0477] Conductors 546 and 548 are connected to the capacitive element 600, the transistor 500, or It functions as a plug or wiring to connect to the transistor 550. Conductor 546, The conductor 548 is provided using the same material as the conductors 328 and 330. It is possible.

[0478] Furthermore, after the formation of the transistor 500, an opening is formed to surround the transistor 500. An insulator with high barrier properties against hydrogen or water may be formed to cover the opening. By encasing the transistor 500 in the aforementioned high-barrier insulator, moisture and other elements are prevented from entering from the outside. This can prevent hydrogen from entering. Alternatively, multiple transistors 500 can be used. Furthermore, it may be wrapped in an insulator with high barrier properties against hydrogen or water. When forming an opening to surround the inverter 500, for example, insulator 522 or insulator 5 The above-mentioned burr forms an opening that reaches 14 and contacts the insulator 522 or insulator 514. By forming a highly insulating material, it can also serve as part of the manufacturing process for transistor 500. , is preferable. Furthermore, an insulator with high barrier properties against hydrogen or water is, for example, The same material as insulator 522 or insulator 514 may be used.

[0479] Next, a capacitive element 600 is provided above the transistor 500. 00 comprises a conductor 610, a conductor 620, and an insulator 630.

[0480] Furthermore, a conductor 612 may be provided on the conductor 546 and the conductor 548. Conductor 6 12 functions as a plug or wire connecting to transistor 500. Conductive Body 610 functions as an electrode for the capacitive element 600. Note that the conductor 612 and The conductor 610 can be formed simultaneously.

[0481] Conductors 612 and 610 contain molybdenum, titanium, tantalum, and tungsten. A metal film containing elements selected from aluminum, copper, chromium, neodymium, and scandium. Alternatively, metal nitride films containing the above-mentioned elements (tantalum nitride film, titanium nitride film, monoxide nitride film) A ribdenum film, tungsten nitride film, etc., can be used. Alternatively, indium tin oxide can be used. Indium oxide containing tungsten oxide, indium zinc containing tungsten oxide Oxides, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, Conductive materials such as indium zinc oxide and indium tin oxide with added silicon oxide are applied. It is also possible.

[0482] In this embodiment, the conductor 612 and the conductor 610 are shown in a single-layer configuration, but this configuration It is not limited to this, and a laminated structure of two or more layers is also acceptable. For example, a conductor with barrier properties and a conductive A conductor with barrier properties between it and a highly conductive conductor, and a conductor that is tightly packed against a highly conductive conductor. A conductive material with high adhesion properties may be formed.

[0483] The insulator 630 can be formed using the same materials as other insulators. A ferroelectric material may be used. Examples of ferroelectric materials include oxidative materials. A mixed crystal of hafnium and zirconium oxide (also called "HZO"), or hafnium oxide. Element X (where element X is silicon (Si), aluminum (Al), gadolinium (Gd)) , yttrium (Y), lanthanum (La), strontium (Sr), etc.) Materials are available. In addition, as insulator 630, piezoelectric ceramic having a perovskite structure is used. A ferroelectric material may be used. For example, lead zirconate titanate (P ZT), strontium bismuth tantalate (SBT), bismuth ferrite (BFO) Alternatively, barium titanate may be used.

[0484] A conductor 620 is provided so as to overlap with the conductor 610 via an insulator 630. The conductor 620 uses a conductive material such as a metallic material, an alloy material, or a metal oxide material. This is possible. High-melting-point materials such as tungsten or molybdenum that offer both heat resistance and conductivity. It is preferable to use a material, and in particular to use tungsten. Also, a conductive material When forming with any other component, use a low-resistance metallic material such as Cu (copper) or Al (algebra). You can use luminium or similar materials.

[0485] An insulator 640 is provided on the conductor 620 and the insulator 630. 0 can be provided using the same material as insulator 379. Also, insulator 640 is It may also function as a flattening film that covers the uneven surface below it.

[0486] By using this configuration, in a semiconductor device using a transistor having an oxide semiconductor, This allows for miniaturization or high integration.

[0487] This embodiment can be appropriately combined with other embodiments shown in this specification and elsewhere.

[0488] (Embodiment 6) In this embodiment, the OS transistor described in the above embodiment can be used. This section will explain metal oxides (hereinafter also referred to as oxide semiconductors).

[0489] The metal oxide preferably contains either indium or zinc. In particular, indium and It is preferable to include zinc. In addition to these, aluminum, gallium, and t It is preferable that it contains elements such as lium and tin. Also, boron, silicon, titanium, and iron are preferable. Nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium One of the following types selected from hafnium, tantalum, tungsten, magnesium, cobalt, etc. , or may include multiple types.

[0490] <Classification of crystal structures> First, we will explain the classification of crystal structures in oxide semiconductors using Figure 24A. Figure 24A shows an oxide semiconductor, typically IGZO (a metal containing In, Ga, and Zn). This is a diagram illustrating the classification of the crystal structure of oxides.

[0491] As shown in Figure 24A, oxide semiconductors can be broadly classified into "Amorphous" It is divided into "Crystalline (crystalline)" and "Crystal (crystal)". They are classified as such. Also, among "Amorphous," there are completely amorp It includes hous. Also, within "Crystalline" there is CAAC(c-ax is-aligned crystalline), nc(nanocrystalli This includes ne), and CAC (Cloud-Aligned Composite). Note that the classification of "Crystalline" includes single crystal, pol Y crystals and completely amorphous crystals are excluded. "Crystal" includes single crystal and poly cry It includes "stal".

[0492] The structures within the thick border shown in Figure 24A are "Amorphous" and "Cry It is an intermediate state between "stal (crystal)" and a new boundary region (New crystal This structure belongs to the "Crystal line phase." In other words, this structure is "Crystal "(crystal)" and the energetically unstable "Amorphous" are completely different. This can be rephrased as a structure.

[0493] The crystal structure of the film or substrate is determined by X-ray diffraction (XRD). It can be evaluated using the (on) spectrum. Here, "Crystalline" GIXD (Grazing-Incidence) of CAAC-IGZO film, which is classified as such. The XRD spectrum obtained by the XRD measurement is shown in Figure 24B. Note that the GIXD method is used for thin films. This method is also called the Seemann-Bohlin method. Hereafter, the GIXD measurement shown in Figure 24B will be used. The XRD spectrum obtained is simply referred to as the XRD spectrum. Note that C shown in Figure 24B The composition of the AAC-IGZO film is approximately In:Ga:Zn = 4:2:3 [atomic ratio]. Furthermore, the thickness of the CAAC-IGZO film shown in Figure 24B is 500 nm.

[0494] As shown in Figure 24B, the XRD spectrum of the CAAC-IGZO film clearly shows crystallinity. The peak shown is detected. Specifically, in the XRD spectrum of the CAAC-IGZO film, A peak indicating c-axis orientation is detected near 2θ = 31°. Furthermore, as shown in Figure 24B... The peaks near 2θ = 31° are asymmetrical with respect to the angle at which the peak intensity was detected.

[0495] Furthermore, the crystal structure of the film or substrate is determined by nano-beam diffraction (NBED). Diffraction patterns observed by electron diffraction (extremely low-voltage electrons) This can be evaluated using the sub-ray diffraction pattern (also called the sub-ray diffraction pattern). Diffraction of CAAC-IGZO film The pattern is shown in Figure 24C. Figure 24C shows an NBE with an electron beam incident parallel to the substrate. This is the diffraction pattern observed by D. Note that the CAAC-IGZO film shown in Figure 24C The composition is approximately In:Ga:Zn=4:2:3 [atomic ratio]. Also, the microelectron beam... In the diffraction method, electron diffraction is performed with a probe diameter of 1 nm.

[0496] As shown in Figure 24C, the diffraction pattern of the CAAC-IGZO film shows multiple c-axis orientations. Spots of this nature can be observed.

[0497] <<Oxide semiconductor structure>> Note that oxide semiconductors may be classified differently from those shown in Figure 24A when considering their crystal structure. Yes, there are. For example, oxide semiconductors include single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. It can be divided into two parts. Examples of non-single-crystal oxide semiconductors include the aforementioned CAAC-OS. And there is nc-OS. In addition, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors and pseudo-non-crystalline oxide semiconductors. crystalline oxide semiconductor (a-like OS: amorphous-like oxide) This includes semiconductors, amorphous oxide semiconductors, and so on.

[0498] Here, we will provide details on the CAAC-OS, nc-OS, and a-like OS mentioned above. Give an explanation.

[0499] [CAAC-OS] CAAC-OS has multiple crystalline regions, and these multiple crystalline regions are arranged with their c-axis in a specific direction. It is an oxide semiconductor that is oriented in a particular direction. Note that the specific direction refers to the thickness direction of the CAAC-OS film. The direction normal to the surface on which the CAAC-OS film is formed, or the direction normal to the surface of the CAAC-OS film. Furthermore, a crystalline region is a region in which the atomic arrangement has periodicity. If considered as an arrangement, a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC-O S has a region in the ab-plane direction where multiple crystalline regions are connected, and this region is strained. This can sometimes occur. Note that strain refers to the deformation of the lattice arrangement in a region where multiple crystal regions are connected. Areas where the orientation of the grid arrangement changes between aligned regions and aligned regions with a different grid arrangement. This refers to the fact that CAAC-OS is c-axis oriented and has a clear orientation in the ab-plane direction. It is an oxide semiconductor that does not exist.

[0500] Each of the above multiple crystalline regions is composed of one or more minute crystals (with a maximum diameter of 10n It is composed of crystals that are less than m in size. If the crystalline region is composed of one minute crystal, The maximum diameter of the crystalline region is less than 10 nm. Furthermore, the crystalline region is composed of numerous tiny crystals. If this is the case, the size of the crystalline region may be around several tens of nanometers.

[0501] In addition, In-M-Zn oxide (where M is aluminum, gallium, yttrium, and tin) In one or more types selected from titanium, etc., CAAC-OS is indigenous A layer containing ions (In) and oxygen (hereinafter referred to as the In layer), and an element M, zinc (Zn), and oxygen A layered crystalline structure (also called a layered structure) is formed by stacking layers containing (M,Zn) layers. ) tends to have. Furthermore, indium and element M are mutually substitutable. Therefore, The (M,Zn) layer may contain indium. Additionally, the In layer contains the element M. This may occur. Furthermore, the In layer may also contain Zn. This layered structure is, for example, In high-resolution TEM images, it is observed as a grid pattern.

[0502] When structural analysis of a CAAC-OS film is performed using, for example, an XRD instrument, the θ / 2θ skid is observed. Out-of-plane XRD measurements using a champ showed a peak indicating c-axis orientation at 2θ. It is detected at 31° or near that angle. Note that the position of the peak indicating c-axis orientation (value of 2θ) This may vary depending on the type and composition of the metal elements that make up CAAC-OS.

[0503] Furthermore, for example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots (spots) may be observed. ) is observed. Note that one spot and another spot are determined by the incident electron beam that has passed through the sample. Observations are made at point-symmetric positions with respect to the spot (also called a direct spot) as the center of symmetry. ru.

[0504] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is a hexagonal lattice. While this is the basic principle, the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. Also, In the distortion described, there may be grid arrangements such as pentagons and heptagons. Note that CAAC- In OS, clear grain boundaries can be observed even near strain. It is not possible. In other words, the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This can be seen. This is because CAAC-OS has a dense arrangement of oxygen atoms in the ab-plane direction. Due to the absence of certain elements, the substitution of metal atoms, which changes the bond distance between atoms, This is thought to be because it allows for distortion to be tolerated.

[0505] Furthermore, a crystal structure in which clear grain boundaries can be observed is known as polycrystalline. It is called l). The grain boundaries become recombination centers, where carriers are trapped and the transistor is formed This is highly likely to cause a decrease in current, a decrease in field-effect mobility, etc. Therefore, a clear conclusion is reached. CAAC-OS, which lacks visible grain boundaries, has a crystal structure suitable for the semiconductor layer of transistors. It is one of the crystalline oxides. Note that CAAC-OS requires the presence of Zn. The configuration is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are In oxide It is preferable because it can suppress the generation of grain boundaries more effectively than other materials.

[0506] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less prone to a decrease in electron mobility caused by grain boundaries. Furthermore, the crystallinity of oxide semiconductors decreases due to the inclusion of impurities or the generation of defects. Because of this, CAAC-OS is an oxide semiconductor with fewer impurities and defects (such as oxygen deficiencies). It can also be called a conductor. Therefore, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are highly heat-resistant and reliable. CAAC-OS is stable even at high temperatures (so-called thermal budget) during the manufacturing process. It is fixed. Therefore, using CAAC-OS in OS transistors allows for freedom in the manufacturing process. It becomes possible to widen the range.

[0507] [nc-OS] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially between 1 nm and 3 nm). It has periodicity in the atomic arrangement in the region of less than nm. In other words, nc-OS is minute It has crystals. The size of these minute crystals is, for example, between 1 nm and 10 nm. In particular, because they are between 1 nm and 3 nm in size, these minute crystals are also called nanocrystals. In nc-OS, no regularity is observed in the crystal orientation between different nanocrystals. Therefore, across the entire film... No orientation is observed. Therefore, nc-OS is a-like depending on the analytical method. It may be indistinguishable from OS or amorphous oxide semiconductors. For example, when comparing nc-OS films Furthermore, when performing structural analysis using an XRD device, out-of-p In lane XRD measurements, no peaks indicating crystallinity were detected. Furthermore, in the nc-OS film... In contrast, electron beams with probe diameters larger than nanocrystals (e.g., 50 nm or larger) are used. When diffraction (also called limited-field electron diffraction) is performed, a diffraction pattern similar to a halo pattern is produced. This is observed. On the other hand, for nc-OS films, the size is close to or smaller than that of nanocrystals. Electron diffraction (nanobial diffraction) using an electron beam with a probe diameter (e.g., 1 nm to 30 nm) Also called electron diffraction. When this is performed, a ring-shaped region centered on the direct spot is observed. In some cases, an electron diffraction pattern with multiple spots observed may be obtained.

[0508] [a-like OS] a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. It is a conductor. a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, it has a-like properties. OS has a higher hydrogen concentration in the membrane compared to nc-OS and CAAC-OS.

[0509] <<Oxide Semiconductor Composition>> Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS is a material composition. Regarding.

[0510] [CAC-OS] CAC-OS refers to, for example, metal oxides in which the elements constituting the metal oxide are between 0.5 nm and 10 nm in size. Preferably, a composition of material that is unevenly distributed with a size of 1 nm to 3 nm or near that size. In addition, in the following, in a metal oxide, one or more metal elements are unevenly distributed, The region containing the metallic element is 0.5 nm to 10 nm, preferably 1 nm to 3 nm. The following state, where particles of similar or near-similar size are mixed, is also referred to as a mosaic or patchy appearance.

[0511] Furthermore, CAC-OS is a system where the material separates into a first region and a second region, resulting in a mosaic effect. This results in a cloud-like structure, where the first region is distributed within the membrane (hereinafter also referred to as a cloud-like structure). Therefore, CAC-OS is a mixture of the first region and the second region. It is a composite metal oxide having the following configuration.

[0512] Here, In for the metal elements constituting CAC-OS in In-Ga-Zn oxide The atomic ratios of Ga and Zn are expressed as [In], [Ga], and [Zn] respectively. To note, for example, in CAC-OS in In-Ga-Zn oxide, the first region is This is the region where [In] is greater than the [In] in the composition of the CAC-OS film. The second region is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. Yes. Or, for example, in the first region, [In] is greater than [In] in the second region. This is a region where the [Ga] is large and smaller than the [Ga] in the second region. In the second region, [Ga] is greater than [Ga] in the first region, and [In This is a region smaller than [In] in the first region.

[0513] Specifically, the first region mentioned above is mainly composed of indium oxide, indium zinc oxide, etc. This is the region. Furthermore, the second region mentioned above includes gallium oxide, gallium zinc oxide, etc. This is the region in which is the principal component. In other words, the first region described above is called the region in which In is the principal component. It can be replaced. Furthermore, the second region mentioned above can be rephrased as the region with Ga as the main component. It is possible.

[0514] Furthermore, a clear boundary may not be observed between the first region and the second region described above.

[0515] For example, in CAC-OS in In-Ga-Zn oxide, energy-dispersive X-ray spectroscopy is used. Law(EDX:Energy Dispersive X-ray spectrosco The EDX mapping obtained using py) shows the region with In as the main component (the first region) It has a structure in which a region mainly composed of ) and a region mainly composed of Ga (the second region) are unevenly distributed and mixed. This can be confirmed.

[0516] When CAC-OS is used in a transistor, the conductivity is due to the first region and the second region The insulating properties resulting from this work in a complementary manner to enable the switching function (On / The function to turn it off can be added to CAC-OS. In other words, CAC-OS is In part of the material, it has conductive properties, and in part of the material, it has insulating properties, and the whole material It has the function of a semiconductor. By separating the conductive function and the insulating function, dual This allows for maximizing the functionality of the transistor. Therefore, CAC-OS is used in transistors. As a result, high on-current (I on ), high field-effect mobility (μ), and good switching This enables the implementation of a specific action.

[0517] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and CA. It may have two or more of the following: C-OS, nc-OS, and CAAC-OS.

[0518] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0519] By using the above oxide semiconductor in transistors, transistors with high field-effect mobility can be produced. It can be achieved. Furthermore, highly reliable transistors can be realized.

[0520] It is preferable to use an oxide semiconductor with a low carrier concentration for the transistor. For example, The carrier concentration of oxide semiconductors is 1 × 10⁻⁶ 17 cm -3 The following is preferably 1 × 10 15 cm -3 More preferably 1 × 10 13 cm -3 More preferably 1 × 10 11 c m -3 More preferably 1 × 10 10 cm -3 It is less than 1 × 10 -9 cm -3 That concludes the explanation. Furthermore, when lowering the carrier concentration of the oxide semiconductor film, The impurity concentration in the conductive film can be reduced to lower the defect level density. In this specification, High-purity intrinsic or substantially high-purity intrinsic refers to a product with a low impurity concentration and a low defect level density. Furthermore, oxide semiconductors with low carrier concentrations are subjected to high-purity intrinsic or substantially high-purity intrinsic oxidation. It is sometimes referred to as a material semiconductor.

[0521] Furthermore, oxide semiconductor films that are high-purity intrinsic or substantially high-purity intrinsic have a low defect level density. Therefore, the trap level density may also be low.

[0522] Furthermore, the time required for charges trapped in the trap levels of oxide semiconductors to disappear is long. Furthermore, it can behave as if it were a fixed charge. Therefore, it can behave as if it were a fixed charge. Transistors in which a channel formation region is formed in an oxide semiconductor exhibit unstable electrical properties. There are cases where this is the case.

[0523] Therefore, in order to stabilize the electrical characteristics of the transistor, the impurity concentration in the oxide semiconductor must be Reducing it is effective. Also, in order to reduce the impurity concentration in oxide semiconductors, It is also preferable to reduce the concentration of impurities in the contacting film. Examples of impurities include hydrogen, nitrogen, and aluminum. Examples include potash metals, alkaline earth metals, iron, nickel, and silicon.

[0524] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0525] In oxide semiconductors, when silicon and carbon, which are among the Group 14 elements, are present, acid Defect levels are formed in oxide semiconductors. Therefore, silicon in oxide semiconductors The concentration of carbon and the concentrations of silicon and carbon near the interface with the oxide semiconductor (secondary ions) Secondary Ion Mass Spectrometer (SIMS) The concentration obtained by (ry) is 2 × 10 18 atoms / cm 3 The following is preferably 2× 10 17 atoms / cm 3 The following applies:

[0526] Furthermore, if alkali metals or alkaline earth metals are present in the oxide semiconductor, defect levels are formed. And, it may generate carriers. Therefore, alkali metals or alkaline earth metals are included. Transistors using oxide semiconductors tend to exhibit normally-on characteristics. Therefore, the concentration of alkali metals or alkaline earth metals in oxide semiconductors obtained by SIMS. to, 1 × 10 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0527] Furthermore, in oxide semiconductors, when nitrogen is present, electrons, which are carriers, are generated. The concentration increases, making it easier to convert to n-type. As a result, oxide semiconductors containing nitrogen become semiconductors. The transistor used tends to exhibit normally-on characteristics. Alternatively, in oxide semiconductors... If nitrogen is present, a trap level may be formed. As a result, the transistor Electrical properties may become unstable. For this reason, in oxide semiconductors obtained by SIMS... The nitrogen concentration is 5 × 10 19 atoms / cm 3 Less than 5 × 10 18 Atom s / cm 3 More preferably 1 × 10 18 atoms / cm 3 More preferably, is 5 x 10 17 atoms / cm 3 Do the following:

[0528] Furthermore, the hydrogen contained in oxide semiconductors reacts with the oxygen bonded to the metal atoms to form water. This can sometimes form an oxygen vacancy. When hydrogen enters this oxygen vacancy, the electrons, which are carriers, In some cases, this can be generated. Also, some of the hydrogen combines with oxygen that is bonded to a metal atom, resulting in a It can generate electrons, which are rear electrons. Therefore, using an oxide semiconductor containing hydrogen... Transistors tend to exhibit normally-on characteristics. For this reason, hydrogen in oxide semiconductors It is preferable that it be reduced as much as possible. Specifically, in oxide semiconductors, SIM The hydrogen concentration obtained by S is 1 × 10 20 atoms / cm 3 Less than 1 × 1 0 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 less than, More preferably 1 × 10 18 atoms / cm 3 Make it less than.

[0529] Using oxide semiconductors with sufficiently reduced impurities in the channel formation region of transistors. This allows for the provision of stable electrical characteristics.

[0530] This embodiment can be appropriately combined with other embodiments shown in this specification and elsewhere.

[0531] (Embodiment 7) In this embodiment, as an example of a semiconductor device, an IC chip, an electronic component, an electronic device, etc. I will explain.

[0532] <Examples of methods for manufacturing electronic components> Figure 25A is a flowchart showing an example of a method for manufacturing electronic components. Electronic components are semiconductor components. Also called a package, or IC package. This electronic component has terminals with a specific orientation and Depending on the shape of the terminal, there are multiple standards and names. Therefore, in this embodiment, Let me explain one example.

[0533] A semiconductor device composed of transistors goes through an assembly process (back-end process) to a printed circuit board. It is completed by combining several detachable parts. For subsequent processes, see each of the steps shown in Figure 25A. It can be completed by going through a process. Specifically, the element substrate obtained in the previous process is completed After step ST71, the back surface of the substrate is ground. At this stage, the substrate is thinned. This process reduces warping of the substrate during the previous stage and allows for miniaturization of components. Next, the substrate is divided into multiple chips. Perform the dicing process to separate the ingredients (step ST72).

[0534] Figure 25B is a top view of the semiconductor wafer 7100 before the dicing process. Figure 2 5C is a magnified view of a portion of Figure 25B. The semiconductor wafer 7100 has multiple circuit regions 71 02 is provided. Circuit region 7102 contains a semiconductor device according to an embodiment of the present invention (for example) (A holding circuit, memory device, imaging device, MCU, etc.) are provided.

[0535] Multiple circuit regions 7102 are each surrounded by isolation regions 7104. Isolation region 71 A dividing line (also called a "dicing line") 7106 is set at a position that overlaps with 04. In the dicing process (step ST72), the semiconductor wafer 710 is diced along the separation line 7106. By cutting off 0, the chip 7110 containing the circuit region 7102 is separated from the semiconductor wafer 7100. Then cut it out. Figure 25D shows a magnified view of chip 7110.

[0536] A conductive layer or semiconductor layer may be provided in the isolation region 7104. Alternatively, by providing a semiconductor layer, ESD that may occur during the dicing process is mitigated, and dicing This prevents a decrease in yield caused by the process. Also, the dicing process is generally based For purposes such as cooling the plate, removing shavings, and preventing static electricity, carbon dioxide and other gases are dissolved to create a specific resistance The process is carried out while supplying purified water with reduced resistance to the cutting area. A conductive layer or semiconductor is placed in the separation region 7104. By adding a layer, the amount of pure water used can be reduced. Therefore, the production of semiconductor devices Production costs can be reduced. Furthermore, the productivity of semiconductor equipment can be increased.

[0537] After performing step ST72, the separated chips are picked up individually and placed on the lead frame. The die bonding process is performed (step ST73) to mount and join the components on top. The bonding method between the chip and lead frame during the manufacturing process should be selected to suit the product. Good. For example, bonding can be done with resin or tape. The die bonding process is, The chip may be mounted on the interposer and bonded. In the wire bonding process, The leads on the frame and the electrodes on the chip are electrically connected with thin metal wires. Step ST74). For the thin metal wire, silver or gold wire can be used. The bonding can be either ball bonding or wedge bonding.

[0538] The wire-bonded chips are then sealed with epoxy resin or the like in a molding process. (Step ST75). The inside of the electronic component is filled with resin by the molding process. This reduces damage to the internal circuitry and wires caused by mechanical external forces. Furthermore, it can reduce the deterioration of properties due to moisture and / or dust. The lead of the tube is plated. Then the lead is cut and shaped (step ST76). ). Plating prevents lead rusting and makes soldering easier when mounting to a printed circuit board later. This can be done more reliably. Printing (marking) is applied to the surface of the package. Step ST77). After the inspection process (Step ST78), the electronic component is completed (Step (ST79). By incorporating the semiconductor device of the above embodiment, low power consumption and compact size can be achieved. We can provide electronic components.

[0539] Figure 25E shows a schematic perspective view of the completed electronic component. Figure 25E shows an example of an electronic component. Figure 25E shows a schematic perspective view of a QFP (Quad Flat Package). As shown, the electronic component 7000 has a lead 7001 and a chip 7110.

[0540] The electronic component 7000 is mounted on a printed circuit board 7002, for example. Multiple 000s are combined, and each is electrically connected on the printed circuit board 7002. This allows it to be mounted in electronic devices. The completed circuit board 7004 can be mounted in electronic devices, etc. It is installed in the section. By incorporating the 7000 electronic component, the power consumption of electronic devices is reduced. This makes it possible to do so. Alternatively, it becomes easier to miniaturize electronic devices.

[0541] Electronic component 7000 is used in digital signal processing, software-defined radio, avionics (communication equipment, Aerospace electronic equipment such as navigation systems, autopilots, and flight management systems, ASICs Prototyping, medical image processing, speech recognition, cryptography, bioinformatics (bio A wide range of fields, including physical information science, mechanical device emulators, and radio telescopes in radio astronomy. It can be applied to electronic components (IC chips) of electronic devices in various fields. Sub-devices include cameras (video cameras, digital still cameras, etc.), display devices, and personal computers. Personal computers (PCs), mobile phones, game consoles including portable devices, and portable information terminals (smartphones) (Phone...

Claims

[Claim 1] A comparison unit that compares the current value of the first signal with the current value of the second signal, A first digital-to-analog conversion unit and a second digital-to-analog conversion unit, A semiconductor device comprising a control unit, The comparison unit is, It has a function to compare the first signal and the second signal and generate an output signal, The control unit, A function to generate code bits according to the output signal, The function of generating digital signals, It has a function to output the aforementioned code bits and the aforementioned digital signals, The first digital-to-analog conversion unit is, The system includes a function to add a current of a current value corresponding to the digital signal to the first signal, The second digital-to-analog conversion unit is, A semiconductor device having a function to add a current of a current value corresponding to the digital signal to the second signal.

Images