Semiconductor equipment

Abstract

The present invention provides a semiconductor device that uses a unipolar transistor to represent a high or low level without a steady current flowing. [Solution] The semiconductor device 10 includes transistors 11 to 14, capacitive elements C11 and C12, first and second wirings, first and second input terminals, and an output terminal. The gate of the fourth transistor 14 is electrically connected to the first input terminal SI_IN, one terminal of the capacitive element C11, and the gate of transistor 11. The gate of transistor 12 is electrically connected to the second input terminal SIB_IN. One source or drain of transistor 11 is electrically connected to the first wiring VSS_IN, and the other is electrically connected to the other terminal of the capacitive elements C11 and C12, one source or drain of transistor 13, and the output terminal SO_OUT. The other source or drain of transistor 12 and the other source or drain of transistor 13 are electrically connected to the second wiring VDD_IN.

Description

Technical Field

[0001] One aspect of the present invention relates to a logic circuit configured using unipolar transistors.

[0002] Also, one aspect of the present invention relates to a semiconductor device. In this specification and the like, a semiconductor device refers to all devices that can function by utilizing semiconductor characteristics. For example, integrated circuits, chips equipped with integrated circuits, electronic components in which chips are housed in packages, and electronic devices equipped with integrated circuits are examples of semiconductor devices.

[0003] Note that one aspect of the present invention is not limited to the above technical field. The technical field of the invention disclosed in this specification and the like relates to things, methods, or manufacturing methods. Or, one aspect of the present invention relates to processes, machines, manufactures, or compositions (composition of matter).

Background Art

[0004] As a circuit (also referred to as a digital circuit or a logic circuit) that handles digital signals represented by high level or low level (which may be represented as High or Low, H or L, 1 or 0, etc.), CMOS (Complementary Metal Oxide Semiconductor) circuits are widely used. <9000089>

[0005] In many cases, a high power supply potential and a low power supply potential are supplied to the logic circuit, the high level is represented using the high power supply potential, and the low level is represented using the low power supply potential. Also, a CMOS circuit is, for example, configured using an n-channel transistor and a p-channel transistor formed on a single crystal silicon substrate.

[0006] A CMOS circuit has a circuit configuration in which an n-channel transistor and a p-channel transistor are connected in series between a high power supply potential and a low power supply potential. When the n-channel transistor is in the conducting state, the p-channel transistor is in the non-conducting state, and when the n-channel transistor is in the non-conducting state, the p-channel transistor is in the conducting state. That is, after a high level or a low level is determined, no through current flows from the high power supply potential to the low power supply potential (excluding the off-current of the transistor, etc.). Here, in cases where both an n-channel transistor and a p-channel transistor cannot be fabricated, or in cases where it is desired to reduce the transistor fabrication process for cost reduction, etc., a logic circuit may be configured using only one of an n-channel transistor or a p-channel transistor (also referred to as a unipolar transistor or a single-channel transistor). For example, Patent Document 1 and Patent Document 2 disclose examples of semiconductor devices and drive circuits of display devices configured using unipolar transistors. In Patent Document 1 and Patent Document 2, two unipolar transistors are connected in series between a high power supply potential and a low power supply potential, and a first signal and a second signal whose logic (high level or low level) of the first signal is inverted are input to the gates of the transistors respectively, and have a circuit configuration in which no through current flows from the high power supply potential to the low power supply potential. The method of using the first signal and the second signal whose logic of the first signal is inverted may be called dual rail.

[0007]

[0008]

[0009] ​​​​​​​​​​​​​​​Furthermore, Patent Documents 1 and 2 describe either the high level or the low level of the output signal. However, the problem of not reaching a high or low power supply potential is resolved by the gate between the output terminal and one of the transistors. This is solved by adding capacitance between the output terminal and one of the transistors. The method of creating space between the torso and the torso is called bootstrap. There is a match.

[0010] On the other hand, transistors having a metal oxide in the channel formation region (oxide semiconductor transistors) OS transistors (also known as OS transistors) have been attracting attention in recent years. As for OS transistors, n Channel transistors have been put into practical use, and they have very low off-current, source and drain Thin-film transistors are capable of having a high voltage applied between them (also known as having high voltage resistance). It has features such as being able to be installed in layers. Furthermore, OS transistors are suitable for high-temperature environments. However, the off-current does not increase easily, and the ratio of on-current to off-current remains large even in high-temperature environments. Semiconductor devices that possess these characteristics and are constructed using OS transistors are highly reliable.

[0011] For example, Patent Document 3 describes a semiconductor substrate on which peripheral circuits such as drive circuits and control circuits are formed. , a semiconductor device having multiple memory cells using OS transistors, and DRAM ( The memory cells of Dynamic Random Access Memory (OST) An example using a converter is disclosed. For example, Si formed on a single-crystal silicon substrate. A peripheral circuit is constructed using transistors, and above it is a memory using OS transistors. Cells can be stacked and arranged. Memory cells using OS transistors are connected to peripheral circuits. By placing it on a single-crystal silicon substrate on which it is formed, the chip area can be reduced. Also, OS Because the off-current of the transistor is very small, it can retain stored data for a long time. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Application Publication No. 9-246936 [Patent Document 2] Japanese Patent Publication No. 2002-328643 [Patent Document 3] Japanese Patent Publication No. 2012-256820 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] Patent documents 1 and 2 employ a dual rail and bootstrap, and Although it is a logic circuit constructed using polar transistors, it is similar to a CMOS circuit in that it is high Once the level or low level is determined, no through-current flows from the high power supply potential to the low power supply potential. It has the characteristic of (also known as not allowing steady-state current to flow), and uses a high power supply potential to produce high levels, while low levels A circuit is disclosed that can represent a low level using the source potential.

[0014] Here, the bootstrap is applied to a transistor with capacitance between the source and gate. Furthermore, the gate voltage Vgs relative to the source of the transistor must be sufficiently maintained. This is preferable. If the gate voltage Vgs relative to the source of the transistor is not sufficiently secured... If the high level does not rise to the high power supply potential, or if the low level does not rise to the low power supply potential, In some cases, the price did not drop completely.

[0015] In Patent Documents 1 and 2, the source of the transistor is electrically connected to the output terminal. A capacitance is provided between the source and gate of the transistor. For example, capacitance is provided at the output terminal. When a quantitative load is connected, the potential of the output terminal is at a high level, such as the high power supply potential. In some cases, the voltage may not rise completely, or when it is low, it may not drop completely to the low power supply potential. Ta.

[0016] One embodiment of the present invention is a logic circuit configured using a unipolar transistor, wherein steady current When no current flows and the output is at a high level, the potential of the output terminal rises to the high power supply potential, and the output becomes low. - The objective is to provide a logic circuit in which, when the voltage level is low, the potential of the output terminal drops to the low power supply potential. This is one of the topics. Alternatively, one embodiment of the present invention is a semi-polar transistor configured using a unipolar transistor. In a conductive device, when no steady current flows and the output is at a high level, the potential of the output terminal is high. When the voltage rises to the source potential and the output is at a low level, the potential of the output terminal drops to the low power supply potential. One of the objectives is to provide semiconductor devices.

[0017] Furthermore, one embodiment of the present invention does not necessarily have to solve all of the above problems, but at least It is sufficient if it can solve one problem. Also, the description of the problem above is based on the existence of other problems. This does not preclude the following. Other issues are described in the specification, claims, drawings, etc. This becomes clear from the description in the specification, claims, drawings, etc. It is possible to identify other issues besides those mentioned above. [Means for solving the problem]

[0018] One embodiment of the present invention comprises first to fourth transistors, first and second capacitance elements, and first to The semiconductor device has a second wiring, first and second input terminals, and an output terminal. Either the source or drain of the transistor is electrically connected to the first wiring, and the fourth transistor The source or drain of one transistor is the same as the source or drain of the second transistor. On the other hand, one terminal of the second capacitance element and the gate of the third transistor are electrically connected. The source or drain of the second transistor, the other of which is electrically connected to the second wiring. The gate of the fourth transistor is connected to the first input terminal, one terminal of the first capacitance element, and the The gate of the first transistor is electrically connected to the second input terminal, and the gate of the second transistor is connected to the second input terminal. It is electrically connected to the child. Either the source or the drain of the first transistor is connected to the first wiring. The first transistor is electrically connected to the first capacitor element, with the source or drain of the first transistor being connected to the first capacitor element. The other terminal of the second capacitor, the other terminal of the second capacitor, and the source or drain of the third transistor On the other hand, and electrically connected to the output terminal, the source or drain of the third transistor. The other end is electrically connected to the second wiring.

[0019] Furthermore, in the above configuration, the first potential is supplied to the first wiring and the second potential is supplied to the second wiring. The second potential is supplied, and the second potential is higher than the first potential, and the first signal is input to the first input terminal. Then, the second signal is input to the second input terminal, and the second signal is a signal in which the logic of the first signal is inverted. It is the number.

[0020] Furthermore, in the above configuration, the first to fourth transistors are of the n-channel type.

[0021] Furthermore, in the above embodiment, the first to fourth transistors have a metal oxide in the channel formation region. It has.

[0022] Furthermore, one embodiment of the present invention comprises a first to third transistor, a first and second capacitance element, and A semiconductor device having 1 and 2 wirings, 1 and 2 input terminals, and an output terminal. Either the source or drain of the second transistor is electrically connected to the second input terminal. The source or drain of the second transistor is connected to one terminal of the second capacitance element, and Furthermore, the gate of the third transistor is electrically connected to the gate of the second transistor. It is electrically connected to the wiring. Either the source or the drain of the first transistor is connected to the first wire. The first transistor's gate is electrically connected to the first input terminal and the first capacitance. It is electrically connected to one terminal of the element and to the other of the source or drain of the first transistor. This refers to the other terminal of the first capacitance element, the other terminal of the second capacitance element, and the source of the third transistor. Alternatively, one of the drains and the output terminals are electrically connected to the third transistor's saw The other end of the drain or cable is electrically connected to the second wiring.

[0023] Furthermore, in the above configuration, the first potential is supplied to the first wiring and the second potential is supplied to the second wiring. The second potential is supplied, and the second potential is higher than the first potential, and the first signal is input to the first input terminal. Then, the second signal is input to the second input terminal, and the second signal is a signal in which the logic of the first signal is inverted. It is the number.

[0024] Furthermore, in the above configuration, the first to third transistors are of the n-channel type.

[0025] Furthermore, in the above embodiment, the first to third transistors have a metal oxide in the channel formation region. It has.

[0026] Furthermore, one embodiment of the present invention comprises a first to seventh transistor, a first to third capacitance element, and a first The semiconductor device has a second wiring, first to fourth input terminals, and an output terminal. One of the 6 transistors, either the source or the drain, is electrically connected to the 1st wiring, and the 6th transistor... The source or drain of the transistor, the other of which is the source or drain of the 7th transistor. One side is electrically connected to the other of the source or drain of the 7th transistor, and the other side of the 3rd transistor Either the source or drain of the transistor, and either the source or drain of the fourth transistor. On the other hand, one terminal of the third capacitance element and the gate of the fifth transistor are electrically connected. The other side of the source or drain of the third transistor, and the source of the fourth transistor. The other end of the drain or the other is electrically connected to the second wiring. The gate of the sixth transistor This involves the second input terminal, one terminal of the second capacitance element, and the gate and power of the first transistor. Connected electrically, the gate of the 7th transistor is at the 1st input terminal, and one end of the 1st capacitance element is at the 1st input terminal. The child, and electrically connected to the gate of the second transistor, and the gate of the third transistor. It is electrically connected to the third input terminal, and the gate of the fourth transistor is electrically connected to the fourth input terminal. They are electrically connected. Either the source or drain of the first transistor is electrically connected to the first wiring. They are connected in a specific manner, with the source or drain of the first transistor being connected to the other of the second transistor. It is electrically connected to either the source or the drain of the second transistor. The other end of the input is the other terminal of the first capacitance element, the other terminal of the second capacitance element, and the third capacitance element. The other terminal, either the source or drain of the fifth transistor, and the output terminal and electrical They are connected in a specific manner, and the source or drain of the fifth transistor is electrically connected to the second wiring. Connected.

[0027] Furthermore, in the above configuration, the first potential is supplied to the first wiring and the second potential is supplied to the second wiring. The second potential is supplied, and the second potential is higher than the first potential, and the first signal is input to the first input terminal. Then, the second signal is input to the second input terminal, the third signal is input to the third input terminal, and the fourth The fourth signal is input to the input terminal, and the third signal is the inverted logic of the first signal. The fourth signal is a signal in which the logic of the second signal is inverted.

[0028] Furthermore, in the above configuration, the first to seventh transistors are of the n-channel type.

[0029] Furthermore, in the above embodiment, the first to seventh transistors have a metal oxide in the channel formation region. It has.

[0030] Furthermore, one embodiment of the present invention comprises a first to seventh transistor, a first to third capacitance element, and a first The semiconductor device has a second wiring, first to fourth input terminals, and an output terminal. Either the source or drain of transistor 6, and the source of transistor 7 or One side of the drain is electrically connected to the first wiring and is the source or drain of the sixth transistor. The other side of the rain is the source or drain of the 7th transistor, the other side of the 3rd transistor Either the source or the drain, one terminal of the third capacitance element, and the fifth transistor The gate is electrically connected, and the source or drain of the third transistor is connected to the fourth transistor. It is electrically connected to either the source or drain of the transistor, and the source of the fourth transistor. The other end of the drain or the other is electrically connected to the second wiring. The gate of the sixth transistor This involves the first input terminal, one terminal of the first capacitive element, and the gate and electric current of the first transistor. Connected electrically, the gate of the 7th transistor is at the 2nd input terminal, and one end of the 2nd capacitance element is at the 2nd input terminal. The child, and electrically connected to the gate of the second transistor, and the gate of the third transistor. It is electrically connected to the third input terminal, and the gate of the fourth transistor is electrically connected to the fourth input terminal. They are electrically connected. Either the source or drain of the first transistor, and the second transistor Either the source or drain of the transistor is electrically connected to the first wiring, and the first transistor The other source or drain of the second transistor is the other source or drain of the second transistor. , the other terminal of the first capacitance element, the other terminal of the second capacitance element, the other terminal of the third capacitance element, One of the source or drain of the fifth transistor, and electrically connected to the output terminal. The source or drain of the fifth transistor, or the other of the two, is electrically connected to the second wiring.

[0031] Furthermore, in the above configuration, the first potential is supplied to the first wiring and the second potential is supplied to the second wiring. The second potential is supplied, and the second potential is higher than the first potential, and the first signal is input to the first input terminal. Then, the second signal is input to the second input terminal, the third signal is input to the third input terminal, and the fourth The fourth signal is input to the input terminal, and the third signal is the inverted logic of the first signal. The fourth signal is a signal in which the logic of the second signal is inverted.

[0032] Furthermore, in the above configuration, the first to seventh transistors are of the n-channel type.

[0033] Furthermore, in the above embodiment, the first to seventh transistors have a metal oxide in the channel formation region. It has. [Effects of the Invention]

[0034] According to one embodiment of the present invention, a logic circuit is constructed using a unipolar transistor, When no steady current flows and the output is at a high level, the potential of the output terminal rises to the high power supply potential. This logic circuit provides a mechanism where, when the output is at a low level, the potential of the output terminal drops to the low power supply potential. This is possible. Alternatively, according to one embodiment of the present invention, a unipolar transistor can be used. In a semiconductor device, when no steady current flows and the output is at a high level, the potential of the output terminal... When the voltage rises to a high power supply potential and the output is at a low level, the potential of the output terminal drops to a low power supply potential. We can provide semiconductor devices.

[0035] Furthermore, the description of these effects does not preclude the existence of other effects. The form does not necessarily have to have all of these effects. Other effects are specified in the details. This will become clear from the description in the document, claims, drawings, etc., and the specification, patent It is possible to extract effects other than those listed above from the scope of the claims, drawings, and other descriptions. [Brief explanation of the drawing]

[0036] [Figure 1] Figures 1A and 1B are circuit diagrams showing example configurations of semiconductor devices. [Figure 2] Figure 2 is a timing chart. [Figure 3] Figure 3 is a timing chart. [Figure 4] Figures 4A and 4B show the circuit diagram symbols for transistors. Figures 4C and 4D are circuit diagrams showing example configurations of semiconductor devices. [Figure 5] Figure 5 is a circuit diagram showing an example of a semiconductor device configuration. [Figure 6] Figure 6 is a timing chart. [Figure 7] Figures 7A and 7B are circuit diagrams showing example configurations of semiconductor devices. [Figure 8] Figure 8 is a timing chart. [Figure 9] Figures 9A and 9B show symbols for semiconductor devices. [Figure 10] Figures 10A and 10B are block diagrams showing examples of semiconductor device configurations. [Figure 11] Figure 11 is a timing chart. [Figure 12] Figure 12 is a timing chart. [Figure 13] Figure 13 is a cross-sectional view showing an example of the configuration of a semiconductor device. [Figure 14] Figures 14A, 14B, and 14C are cross-sectional views showing examples of transistor structures. [Figure 15] Figure 15A is a top view showing an example of transistor structure. Figures 15B and 15C are cross-sectional views showing an example of transistor structure. [Figure 16] Figure 16A is a top view showing an example of transistor structure. Figures 16B and 16C are cross-sectional views showing an example of transistor structure. [Figure 17] Figure 17A is a top view showing an example of transistor structure. Figures 17B and 17C are cross-sectional views showing an example of transistor structure. [Figure 18] Figure 18A is a top view showing an example of transistor structure. Figures 18B and 18C are cross-sectional views showing an example of transistor structure. [Figure 19] Figure 19A is a top view showing an example of transistor structure. Figures 19B and 19C are cross-sectional views showing an example of transistor structure. [Figure 20] Figure 20A is a top view showing an example of transistor structure. Figures 20B and 20C are cross-sectional views showing an example of transistor structure. [Figure 21] Figures 21A and 21B are cross-sectional views showing examples of transistor structures. [Figure 22] Figure 22 is a cross-sectional view showing an example of the configuration of a semiconductor device. [Figure 23] Figures 23A and 23B are cross-sectional views showing examples of transistor structures. [Modes for carrying out the invention]

[0037] The embodiments will be described below with reference to the drawings. However, the embodiments may differ in many ways. It is possible to implement it in any form, and without deviating from its purpose and scope, its form and Those skilled in the art will readily understand that the details can be modified in various ways. Therefore, the present invention The following embodiments are not to be interpreted as being limited to their contents.

[0038] Furthermore, the multiple embodiments shown below can be combined as appropriate. If multiple configuration examples are shown within a single embodiment, the configuration examples may be combined as appropriate. It is possible to do so.

[0039] In the drawings attached to this specification, the components are classified by function and are shown as independent blocks. Although a block diagram is shown as an example, the actual components are not completely separated by function. This can be difficult, and a single component may be involved in multiple functions.

[0040] Furthermore, in drawings and other documents, the size, layer thickness, area, etc., may be exaggerated for clarity. Therefore, it is not necessarily limited to that scale. The drawing schematically represents an ideal example. This is an illustration, and is not limited to the shapes or values ​​shown in the drawings.

[0041] Furthermore, in drawings, etc., identical elements or elements with similar functions, elements made of the same material, Alternatively, elements formed simultaneously may be assigned the same reference numeral, and the explanation of this repetition is provided. This may be omitted.

[0042] Furthermore, in this specification, the terms "membrane" and "layer" are interchangeable. 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 terminology to this.

[0043] Furthermore, in this specification, terms indicating placement such as "above" and "below" refer to the relative positions of the constituent elements. The term "directly above" or "directly below" is not necessarily limited to this. For example, "gate absolute" The expression "gate electrode on the margin layer" implies that there are other components between the gate insulating layer and the gate electrode. Items containing this will not be excluded.

[0044] Furthermore, in this specification, ordinal numbers such as "first," "second," and "third" refer to the constituent elements. This is added to avoid confusion and does not limit the number.

[0045] Furthermore, in this specification, "electrically connected" means "having some kind of electrical effect." This includes cases where the connection is made via ". Here, "something that has some electrical effect" The term "connection" is not particularly limited as long as it enables the exchange of electrical signals between connected objects. For example, "things that have some kind of electrical effect" include electrodes and wiring, as well as transistors. Switching elements, resistive elements, inductors, capacitive elements, and other elements with various functions This includes elements and components. Also, even when it is described as "electrically connected," it refers to the actual circuitry. In some cases, there are no physical connections, and only wiring extends from the site.

[0046] Furthermore, in this specification, the terms "electrode" and "wiring" refer to these components functionally. It is not limited to this. For example, "electrode" can be used as part of "wiring". And the reverse is also true.

[0047] Furthermore, in this specification, etc., "terminal" in an electrical circuit means an input of current or potential ( This refers to the part where output or signal reception (or transmission) takes place. Therefore, wiring... Alternatively, a portion of the electrode may function as a terminal.

[0048] Furthermore, generally speaking, "capacitance" refers to a configuration in which two electrodes face each other with an insulator (dielectric) in between. In this specification, the term "capacitive element" includes the case of the "capacitance" described above. In other words, in this specification, a "capacitive element" refers to a device in which two electrodes face each other across an insulator. Those with a matching configuration, those with a configuration in which two wires face each other with an insulator in between, This includes cases where two wires are arranged with an insulator in between.

[0049] Furthermore, in this specification, "voltage" refers to a potential and a reference potential (for example, ground). It often refers to the potential difference (electric potential). Therefore, voltage and potential difference can be used interchangeably. can.

[0050] Furthermore, in this specification, the term "transistor" includes a gate, a drain, and a source. It is an element having at least three terminals. And, the drain (drain terminal, drain (Drain region, or drain electrode) and source (source terminal, source region, or source electrode) It has a channel-forming region between it, and the source and drain are separated by the channel-forming region. Current can be passed between them. In this specification, etc., channel forming region A region refers to an area where electric current primarily flows.

[0051] Furthermore, the source and drain functions may vary depending on whether transistors with different polarities are used, or the circuit dynamics may change. In the process, the direction of the current may change, causing the order to be reversed. Therefore, this specification In written documents and other materials, the terms "source" and "drain" may be used interchangeably.

[0052] Furthermore, unless otherwise specified in this specification, off-current refers to the state in which a transistor is in the off state. This refers to the drain current when the device is in a non-conductive state (also called a closed state). Unless otherwise specified, in an n-channel transistor, the gate voltage relative to the source is V When gs is lower than the threshold voltage Vth, in a p-channel transistor, relative to the source This refers to a state where the gate voltage Vgs is higher than the threshold voltage Vth. In other words, n channels The off-current of a 1-type transistor is the voltage Vgs of the gate relative to the source relative to the threshold voltage V In some cases, the drain current is defined as the current when it is lower than th.

[0053] In the above explanation of off-current, you may substitute "drain" for "source." That is, off-current This can refer to the source current when the transistor is in the off state. In the same sense, it is sometimes called leakage current. Also, in this specification, etc., off current is The field refers to the current that flows between the source and drain when the transistor is in the off state. There is a match.

[0054] Furthermore, in this specification, on-current refers to the state in which a transistor is on (conductive state, also known as... In the case of (u), it can refer to the current flowing between the source and the drain.

[0055] Furthermore, in this specification, metal oxide refers to a broad term. It is a metal oxide. Metal oxides are oxide insulators and oxide conductors (transparent oxide conductors, It is classified as an oxide semiconductor, etc. (including [specific type of semiconductor]).

[0056] For example, when a metal oxide is used in the channel formation region of a transistor, the metal oxide It is sometimes called an oxide semiconductor. In other words, the metal oxide has amplification, rectification, and If it has at least one wetting action, the metal oxide is a metal oxide semiconductor ( It can be called a metal oxide semiconductor. A transistor having a metal oxide in the channel formation region is called an "oxide semiconductor transistor." It can be called an "OS transistor". Similarly, as mentioned above, it uses an oxide semiconductor. A "transistor" is also a transistor that has a metal oxide in its channel formation region.

[0057] Furthermore, in this specification, metal oxides containing nitrogen are also referred to as metal oxides (metal oxi They are sometimes referred to as (de). Also, metal oxides containing nitrogen are called metal oxynitrides (met It may also be called al oxynitride. Details about metal oxides will be described later. .

[0058] (Embodiment 1) This embodiment describes an example of the configuration of a semiconductor device according to one embodiment of the present invention. One form of semiconductor device is constructed using unipolar transistors and has a high power supply potential. This is a logic circuit where a high level is represented using a specific power supply potential, and a low level is represented using a low power supply potential. .

[0059] Furthermore, examples of semiconductor devices using n-channel transistors described herein include... This shows that a p-channel transistor can also be used. The change from a p-channel transistor is easily understood by those skilled in the art, therefore I will omit the explanation.

[0060] <Example 1 of semiconductor device configuration> Figure 1A is a circuit diagram showing an example configuration of the semiconductor device 10. The semiconductor device 10 is one of the present inventions. A semiconductor device relating to its form, comprising transistors 11 to 14, and a capacitive element C1 1, and a capacitive element C12. Transistors 11 to 14 are n-type It is a channel-type transistor.

[0061] The semiconductor device 10 has a wiring VSS_IN to which a low power supply potential VSS is supplied, and a high power supply potential VDD. The wiring supplied is VDD_IN, the input terminal SI_IN receives the signal SI, and the signal SIB is input to this terminal. The input terminal SIB_IN receives the signal, and the output terminal SO_OU receives the signal SO. It has T.

[0062] Here, the high power supply potential VDD is a higher potential than the low power supply potential VSS, and the low power supply potential VS S may be the reference potential in the semiconductor device 10. Also, signal SI and signal SI B is a digital signal, and the potential representing the high levels of signals SI and SIB is the high power supply. The position is VDD, and the potential representing the low level is the low power supply potential VSS. Also, the signal SIB is This is a signal in which the logic of signal SI is inverted.

[0063] In the semiconductor device 10, either the source or the drain of the transistor 14 is connected to the wiring VS S_IN is electrically connected, and the other end of the source or drain of transistor 14 is connected to the transistor. One of the source or drain terminals of the converter 12, one terminal of the capacitive element C12, and Electrically connected to the gate of transistor 13, and to the source or drain of transistor 12. The other end is electrically connected to the wiring VDD_IN.

[0064] The gate of transistor 14 is connected to the input terminal SI_IN, one terminal of the capacitive element C11, and The gate of transistor 11 is electrically connected to the input, and the gate of transistor 12 is connected to the input. It is electrically connected to terminal SIB_IN.

[0065] Either the source or drain of transistor 11 is electrically connected to the wiring VSS_IN. The source or drain of transistor 11 is connected to the other terminal of capacitive element C11. The other terminal of the capacitive element C12, one of the source or drain of the transistor 13, and It is electrically connected to the output terminal SO_OUT, and is the source or drain of transistor 13. The other end is electrically connected to the wiring VDD_IN.

[0066] Here, the other of the source or drain of transistor 14 and the source of transistor 12 Alternatively, one of the drains, one terminal of the capacitive element C12, and the gateway of transistor 13. The connection point to the terminal is referred to as node N11.

[0067] <Example of semiconductor device configuration 2> Figure 1B is a circuit diagram showing an example configuration of the semiconductor device 20. The semiconductor device 20 is part of the present invention. This is a semiconductor device related to its form, and is a different configuration example from semiconductor device 10. Semiconductor device 2 0 represents transistors 21 through 23, capacitive element C21, and capacitive element C2 It has 2. Transistors 21 to 23 are n-channel type transistors. be.

[0068] The semiconductor device 20, like the semiconductor device 10, is supplied with a low power supply potential VSS via wiring VSS_ IN is the wiring to which the high power potential VDD is supplied. VDD_IN is the input terminal to which the signal SI is input. SI_IN, the input terminal SIB_IN into which the signal SIB is input, and the output terminal SO It has an output terminal SO_OUT. Note that, to avoid repetitive explanations, the potential and signal are omitted. The explanation of the numbers will be omitted.

[0069] In the semiconductor device 20, either the source or the drain of the transistor 22 is connected to an input terminal. Electrically connected to SIB_IN, the other of the source or drain of transistor 22 is One terminal of the capacitive element C22 is electrically connected to the gate of the transistor 23. The gate of transistor 22 is electrically connected to the wiring VDD_IN.

[0070] Either the source or drain of transistor 21 is electrically connected to the wiring VSS_IN. The gate of transistor 21 is connected to the input terminal SI_IN and to one of the capacitive elements C21. The terminals are electrically connected, and the source or drain of transistor 21 is connected to the other side of the capacitive element. The other terminal of sub-C21, the other terminal of capacitive element C22, the source of transistor 23 or One side of the drain and the output terminal SO_OUT are electrically connected to transistor 23. The source or drain of the other end is electrically connected to the wiring VDD_IN.

[0071] Here, the other end of the source or drain of transistor 22 and one end of the capacitive element C22 The connection point between the child and the gate of transistor 23 is referred to as node N21.

[0072] <Example of semiconductor device operation 1> Figure 2 is a timing chart showing an example of operation of the semiconductor device 10. Figure 2 shows the signal SI, The potentials of signal SIB, node N11, and signal SO are divided into periods D11 to D15. The threshold voltages of transistors 11 to 14 are shown below. Let's assume the voltage value is Vth.

[0073] Period D11 is the period when signal SI is high and signal SIB is low. Because the current is at a high level, transistors 11 and 14 are in a conductive state. Node N11 and signal SO are at a low level. Also, transistor 12 and transistor 12 are at a low level. Zistor 13 is in a non-conductive state.

[0074] During period D12, signal SI changes from high level to low level, and signal SIB is low level. This is part of the period when the signal changes from high level to low level. The period during which the signal changes is called the fall phase, and the period during which it changes from a low level to a high level is called the rise phase. say).

[0075] During period D12, due to capacitive coupling by the capacitive element C11, the signal SI is at a high level. As the level changes to a low level, the signal SO is lower than the low level (low power supply potential VSS). The potential increases. Also, the signal SIB rises from a low level, and the potential between the signal SIB and node N11 When the difference in position exceeds the threshold voltage Vth of transistor 12, transistor 12 enters a conducting state. As a result, the potential of node N11 rises from a low level. As the voltage rises from the rifle, transistor 13 also becomes conductive, and the potential of signal SO becomes low level. The degree of decrease from the threshold is weakened, and in period D13 described later, the potential of signal SO increases. start.

[0076] Period D13 is part of the period when signal SI falls and the period when it is low level, and also includes signal SIB. This is part of the rise time and high-level period. During period D13, the transistor 12 and transistor 13 are in a conducting state, the potential at node N11 rises, and the low level The potential of signal SO, which has become lower than the potential of the transistor, also begins to rise. In addition, transistor 11 and Transistor 14 becomes non-conductive.

[0077] During period D13, the potentials of node N11 and signal SO rise, but signal SO remains low. Because the potential rises from a level lower than the signal level, a potential difference is generated between node N11 and signal SO. Furthermore, the signal SIB becomes high level, causing the potential of node N11 to rise, and the signal SIB When the potential difference between B and node N11 becomes smaller than the threshold voltage Vth of transistor 12, Transistor 12 becomes non-conductive. Transistor 12 becomes non-conductive, but the capacitive element Due to capacitive coupling by child C12, as the potential of signal SO rises, the potential of node N11 also rises. Furthermore, it rises. That is, by having a potential difference between node N11 and signal SO, the node This ensures that the potential of N11 is reliably increased.

[0078] The potential of node N11 rises above the high power supply potential VDD, therefore the signal SO and the high power supply potential Even if the potential difference with VDD becomes smaller than the threshold voltage Vth of transistor 13, Zistor 13 does not become non-conductive. Signal SO rises until it equals the high power supply potential VDD. To rise.

[0079] Period D14 is the period when signal SI rises and signal SIB falls. Transistors 11 and 14 become conductive, and transistor 12 and Transistor 13 becomes non-conductive. That is, node N11 and signal SO are low. It becomes a level.

[0080] Period D15 is the period when signal SI is high level and signal SIB is low level. Since 5 is the same as period D11, the explanation will be omitted.

[0081] As described above, the semiconductor device 10 is a logic circuit composed of n-channel transistors. This is a circuit, and the signal SO output from the output terminal SO_OUT is a high-power supply signal when it is at a high level. It rises to VDD and then drops to the low power supply potential VSS when it is low. In position 10, after the high or low levels of signals SI and SIB are determined This has the characteristic that no through-current flows from the high power supply potential VDD to the low power supply potential VSS.

[0082] <Example of semiconductor device operation 2> Figure 3 is a timing chart showing an example of the operation of the semiconductor device 20. Figure 3 shows the signal SI, The potentials of signal SIB, node N21, and signal SO are divided into periods D21 to D25. The threshold voltages of transistors 21 to 23 are shown below. Let's assume the voltage value is Vth.

[0083] Period D21 is the period when signal SI is high level and signal SIB is low level. Because the current is at a high level, transistor 21 is in a conducting state, and the signal SO is at a low level. Yes. Also, transistor 22 is in a conducting state, and the potential of node N21 is the signal SIB and It is also at a low level. Therefore, transistor 23 is in a non-conductive state.

[0084] During period D22, signal SI changes from high level to low level, and signal SIB is low level. This is part of the period of transition from a high level to a high level.

[0085] During period D22, due to capacitive coupling by the capacitive element C21, the signal SI is at a high level. As the signal changes to a low level, the signal SO becomes lower in potential than the low level. The signal SIB rises from a low level, and the potential at node N21 rises in the same way as the signal SIB. When the potential of node N21 rises from a low level, transistor 23 becomes conductive. Therefore, the degree to which the potential of signal SO drops from a low level is weakened, and in the period D23 described later... Then, the potential of the signal SO begins to rise.

[0086] Period D23 is a portion of the falling edge period of signal SI and the low-level period, as well as signal SIB This is part of the rise period and the high-level period. Node N21 also occurs during period D23. The potential increased, and transistor 23 became conductive, resulting in a potential lower than the low level. The potential of signal SO also begins to rise. Furthermore, transistor 21 becomes non-conductive.

[0087] During period D23, the potentials of node N21 and signal SO rise, but signal SO remains low. Because the potential rises from a level lower than the signal level, a potential difference is generated between node N21 and signal SO. Also, the SIB signal becomes high level, causing the potential of node N21 to rise, and the node The potential difference between N21 and the high power supply potential VDD is smaller than the threshold voltage Vth of transistor 22. When this happens, transistor 22 becomes non-conductive. Transistor 22 becomes non-conductive. However, due to capacitive coupling by the capacitive element C22, as the potential of the signal SO rises, node N21 The potential increases further. That is, there is a potential difference between node N21 and signal SO. This ensures that the potential of node N21 is reliably increased.

[0088] The potential of node N21 rises above the high power supply potential VDD, therefore the signal SO and the high power supply potential Even if the potential difference with VDD becomes smaller than the threshold voltage Vth of transistor 23, Zistor 23 does not become non-conductive. Signal SO rises until it equals the high power supply potential VDD. To rise.

[0089] Period D24 is the period when signal SI is rising and signal SIB is falling. As a result, transistor 21 becomes conductive, the potential of node N21 decreases, and transistor 2 Node 3 becomes non-conductive. That is, node N21 and signal SO become low levels.

[0090] Period D25 is the period when signal SI is high level and signal SIB is low level. Since item 5 is the same as period D21, the explanation will be omitted.

[0091] As described above, the semiconductor device 20 is a logic circuit composed of n-channel transistors. This is a circuit, and the signal SO output from the output terminal SO_OUT is a high-power supply signal when it is at a high level. It rises to VDD and then drops to the low power supply potential VSS when it is low. In step 20, after the high or low levels of signal SI and signal SIB are determined This has the characteristic that no through-current flows from the high power supply potential VDD to the low power supply potential VSS.

[0092] <Transistors that make up a semiconductor device> The semiconductor device 10 comprises transistors 11 and 14, and the semiconductor device The transistors 21 to 23 that make up 20 have a metallic acid in the channel formation region. A transistor containing a chromium (OS transistor) can be used.

[0093] OS transistors have a very low off-current and a high voltage between the source and drain. It has features such as being a thin-film transistor that can be added and can be stacked. Here, the off-current is the drain current when the transistor is in the off state. The band gap of the oxide semiconductor is 2.5 eV or higher, preferably 3.0 eV or higher. OS transistors are characterized by low leakage current due to thermal excitation and very low off-current. The OS transistor has, for example, an off-current of 100 Hz per 1 μm of channel width. A / μm or less, or 10 zA / μm or less, or 1 zA / μm or less, or 10 yA / It can be reduced to μm or less.

[0094] In particular, transistors 12, 14, and 22 have low off-currents. It is preferable to use a transistor. This allows for the use of a transistor during period D13 or period D23. Therefore, even if the period of low signal SI (period of high signal SIB) is long, high power supply The potential of node N11 or node N21, which has risen above the potential VDD, is maintained for an extended period of time. It is possible.

[0095] Furthermore, OS transistors have a low rate of increase in off-current even in high-temperature environments. It has the characteristic of having a large ratio between the on-current and the off-current. It uses an OS transistor in semiconductor equipment. By configuring the device 10 or semiconductor device 20, the reliability of the semiconductor device can be improved. can.

[0096] The metal oxide used in the channel formation region of OS transistors is indium (In) It is preferable that the oxide semiconductor contains at least one of the elements and zinc (Zn). Examples of oxide semiconductors include In-M-Zn oxide (where M is, for example, Al, Ga, Y) Sn is a typical example. By reducing impurities such as water and hydrogen that act as electron donors, Furthermore, by reducing oxygen vacancies, oxide semiconductors can be made i-type (intrinsic) or substantially i-type. It is possible. Such oxide semiconductors are called highly purified oxide semiconductors. This is possible. For details on the OS transistor, see Embodiment 3 and Embodiment 4. I will explain it here.

[0097] Furthermore, since OS transistors are thin-film transistors, they can be stacked and arranged in layers. For example, on a circuit constructed using Si transistors formed on a single-crystal silicon substrate An OS transistor can be provided in the semiconductor device 10 or semiconductor. The chip area of ​​the device 20 can be reduced.

[0098] Alternatively, the transistor 11, the ray transistor 14, and the semiconductor device 10 are all components of the semiconductor device 10. The transistors 21 to 23 that constitute the semiconductor device 20 are OS transistors Other transistors may be used. For example, if the band gap is large in the channel formation region A transistor having a large bandgap semiconductor may also be used. A semiconductor with a large bandgap is a semiconductor with a large bandgap. It can refer to semiconductors with a gap of 2.2 eV or more, such as silicon carbide and galvanized nitride. Examples include lium and diamond.

[0099] Furthermore, transistors 11 to 14 and semiconductors constituting the semiconductor device 10 The transistors 21 to 23 that constitute the main body device 20 have back gates. A transistor may be used.

[0100] As an example of a transistor with a back gate, Figure 4A shows the circuit diagram of transistor 31. The part number is indicated. Transistor 31 has a gate (also called the front gate), drain, and saw It has four terminals, called the S and the back gate. In Figure 4A, each is G These are represented as (gate), D (drain), S (source), and BG (backgate).

[0101] As an example of the use of transistor 31, the back gate is electrically connected to the gate, and the back gate Connect the source electrically, apply a predetermined potential to the back gate, or electrically connect the back gate. It can also be described as being in a floating state (also called floating). For example, the back gate By electrically connecting it to the terminal, the on-current of transistor 31 can be increased. Furthermore, by applying a predetermined potential to the back gate, the threshold voltage of transistor 31 can be controlled. This can be changed. An example of a cross-sectional configuration of a transistor with a back gate is shown in the implementation. This will be explained using Form 3.

[0102] Furthermore, transistors 11 to 14 and semiconductors constituting the semiconductor device 10 Multiple gates (multi A transistor with a gate (also called a gate) may be used.

[0103] As an example of a transistor with multiple gates, Figure 4B shows a transistor with two gates (double gate). The circuit diagram symbol for transistor 32, which has four (also known as ), is shown. Transistor 32 has four It has terminals (gate 1, gate 2, drain, source). In Figure 4B, G These are represented as 1 (gate 1), G2 (gate 2), D (drain), and S (source).

[0104] Examples of transistor 32 use include electrically connecting gate 1 and gate 2, or gate A predetermined potential may be applied to gate 1 or gate 2. For example, gates 1 and 2 may be electrically connected. By connecting it to this, it may be possible to reduce the off-current of transistor 32. Furthermore, by applying a predetermined potential to gate 1 or gate 2, the transistor 32 can withstand voltage. In some cases, it may be possible to use a transistor with high performance.

[0105] For example, a transistor 11 constituting the semiconductor device 10 has a back gate An example using transistor 31 is shown in Figure 4C. In Figure 4C, the backgear of transistor 31 The gate is electrically connected to the gate.

[0106] For example, a transistor 11 that makes up a semiconductor device 10 has two gates An example using transistor 32 is shown in Figure 4D. In Figure 4D, the gate 1 of transistor 32 is It is electrically connected to gate 2.

[0107] Note that this embodiment can be implemented in appropriate combination with other embodiments described in this specification. It can be done.

[0108] (Embodiment 2) In this embodiment, an example of constructing a general-purpose logic circuit by applying the semiconductor device 10 described in the above embodiment will be described. Note that in this specification and the like, when there are a plurality of the same components, in order to distinguish the plurality of components, signs such as "_1" or "[_2]" may be used (for example, semiconductor device 10_1, semiconductor device 10_2).

[0109] <NOT circuit, buffer circuit> FIG. 5 is a circuit diagram showing a configuration example of the semiconductor device 30. The semiconductor device 30 has two semiconductor devices 10 described in the above embodiment, and functions as a NOT circuit for inverting logic or a buffer circuit for not inverting logic. As shown in FIG. 5, the semiconductor device 30 has the semiconductor device 10_1 and the semiconductor device 10_2. For the sake of explanation, in FIG. 5, the semiconductor device 10_1 and the semiconductor device 10_2 are surrounded by a dashed line, and the input / output terminals are indicated by filled circles provided on the dashed line. Also, the input / output potential or signal is represented using an arrow provided on the extension of the wiring.

[0110]

[0111]

[0111] The signal SIB is input to the input terminal SI_IN, and the signal SI is input to the input terminal SIB_IN. It is assumed that the signal SOB is output from the output terminal SO_OUT of the semiconductor device 10_2.

[0112] Next, a timing chart showing an operation example of the semiconductor device 30 is shown in FIG. 6. The signals SI, SIB, and SO are the same as the timing chart shown in FIG. 2, and in FIG. 6, a timing chart of the signal SOB is additionally shown. In the semiconductor device 10_2, since the signals SI and SIB are input in the reverse direction to the semiconductor device 10_1, the signal SOB is a signal whose logic of the signal SO is inverted.

[0113] As described above, the semiconductor device 30 receives the signals SI and SIB and outputs the signals SO and SOB. The signal SIB is a signal whose logic of the signal SI is inverted, and the signal S OB is a signal whose logic of the signal SO is inverted. Therefore, the output terminal of the semiconductor device 30 can be electrically connected to the input terminal of another semiconductor device 30.

[0114] <NAND circuit> FIG. 7A is a circuit diagram showing a configuration example of the semiconductor device 40. The semiconductor device 40 is a semiconductor device applying the semiconductor device 10 and has a function as a NAND circuit. The semiconductor device 40 includes transistors 41 to 47 and capacitor elements C41 to C43. The transistors 41 to 47 are n-channel type transistors.

[0115] The semiconductor device 40 has a wiring VSS_IN to which a low power supply potential VSS is supplied, and a high power supply potential VDD ​​​A wiring VDD_IN to which power is supplied, an input terminal SI1_IN to which a signal SI1 is input, a signal S I2 is input to an input terminal SI2_IN, a signal SI1B is input to an input terminal SI1B_ IN, an input terminal SI2B_IN to which a signal SI2B is input, and an output terminal SO1_OUT from which a signal SO1 is output It has.

[0116] Here, the high power supply potential VDD is a potential higher than the low power supply potential VSS, and the low power supply potential VS S may be a reference potential in the semiconductor device 40. Also, the signal SI1, the signal SI2 , the signal SI1B, and the signal SI2B are digital signals, and the potential representing the high level of the signal SI1, the signal SI2 , the signal SI1B, and the signal SI2B is the high power supply potential VDD , and the potential representing the low level is the low power supply potential VSS. Also, the signal SI1B is a signal in which the logic of the signal SI 1 is inverted, and the signal SI2B is a signal in which the logic of the signal SI2 is inverted .

[0117] In the semiconductor device 40, one of the source or drain of the transistor 46 is electrically connected to the wiring VS S_IN, and the other of the source or drain of the transistor 46 is electrically connected to one of the source or drain of the transistor 47, and the source or drain of the transistor 47 The other is electrically connected to one of the source or drain of the transistor 43, one of the source or drain of the transistor 44, one terminal of the capacitor element C43, and the gate of the transistor 45, and the source or drain of the transistor 43 The other, and the other of the source or drain of the transistor 44 are electrically connected to the wiring VDD_IN One of the source or drain of the transistor 〈0000920〉 IN, and the other of the source or drain of the transistor 43 The other, and the other of the source or drain of the transistor 44 are electrically connected to the wiring VDD_IN It is electrically connected.

[0118] The gate of transistor 46 is electrically connected to the input terminal SI2_IN, one terminal of the capacitive element C42, and the gate of transistor 41. The gate of transistor 47 is electrically connected to the input terminal SI1_IN, one terminal of the capacitive element C41, and the gate of transistor 42. The gate of transistor 43 is electrically connected to the input terminal SI1B_IN, and the gate of transistor 44 is electrically connected to the input terminal SI2B_IN. .

[0119] One of the source or drain of transistor 41 is electrically connected to the wiring VSS_IN, and the other of the source or drain of transistor 41 is electrically connected to one of the source or drain of transistor 42. The other of the source or drain of transistor 42 is electrically connected to the other terminal of the capacitive element C41, the other terminal of the capacitive element C42, the other terminal of the capacitive element C43, one of the source or drain of transistor 45, and the output terminal SO1_OUT, and the other of the source or drain of transistor 45 is electrically connected to the wiring VDD_IN.

[0120] Here, the connection part between the other of the source or drain of transistor 47, one of the source or drain of transistor 43, one of the source or drain of transistor 44, one terminal of the capacitive element C43, and the gate of transistor 45 is referred to as node N41. The operation example of the semiconductor device 40 will be described later.

[0121] <NOR circuit> FIG. 7B is a circuit diagram showing a configuration example of the semiconductor device 50. The semiconductor device 50 is a semiconductor device A semiconductor device applying 10, which has a function as a NOR circuit. The semiconductor device 50 includes transistors 51 to 57 and capacitor elements C51 to C53. The transistors 51 to 57 are n-channel transistors.

[0122] The semiconductor device 50 has a wiring VSS_IN to which a low power supply potential VSS is supplied, a high power supply potential VDD is supplied to the wiring VDD_IN, an input terminal SI1_IN to which a signal SI1 is input, a signal S I2 is input to the input terminal SI2_IN, an input terminal SI1B_ IN to which a signal SI1B is input, an input terminal SI2B_IN to which a signal SI2B is input, and an output terminal SO2_OUT from which a signal SO2 is output . Note that, to avoid repetitive explanations, the descriptions of the potential and the signal are omitted.

[0123] In the semiconductor device 50, one of the source or drain of the transistor 56 and one of the source or drain of the transistor 57 is electrically connected to the wiring VSS_IN, the other of the source or drain of the transistor 56 is the other of the source or drain of the transistor 57, one of the source or drain of the transistor 53, one terminal of the capacitor element C53, and is electrically connected to the gate of the transistor 55, the other of the source or drain of the transistor 53 is electrically connected to one of the source or drain of the transistor 54, the other of the source or drain of the transistor 54 is electrically connected to the wiring VDD_IN . <00,00972> The gate of the transistor 56 is the input terminal SI1_IN, one terminal of the capacitor element C51, and And, electrically connected to the gate of transistor 51, the gate of transistor 57 is The force terminal SI2_IN, one terminal of the capacitive element C52, and the gate of transistor 52. The gate of transistor 53 is electrically connected to the input terminal SI1B_IN. The gate of transistor 54 is connected and electrically connected to the input terminal SI2B_IN. .

[0125] Either the source or drain of transistor 51, and the source of transistor 52 One side of the drain is electrically connected to the wiring VSS_IN and the saw of transistor 51. The other side of the source or drain of transistor 52 is the source or drain of the capacitive element The other terminal of C51, the other terminal of capacitive element C52, the other terminal of capacitive element C53, Either the source or drain of the converter 55, and the output terminal SO2_OUT and electrical The source or drain of transistor 55 is connected to the wiring VDD_IN and the power They are connected by air.

[0126] Here, the source or drain of transistor 56 and the source of transistor 57 or the other side of the drain, one side of the source or drain of transistor 53, capacitive element C5 The connection between one terminal of 3 and the gate of transistor 55 is referred to as node N51. do.

[0127] <Example of semiconductor device operation> Figure 8 is a timing chart showing an example of operation for semiconductor device 40 and semiconductor device 50. Figure 8 shows the potentials of signals SI1, SI2, SI1B, and SI2B, and signal SO1 This shows the relationship with the potential of signal SO2. Note that signals SI1, SI2, and S are shown. The time when the potentials of I1B and signal SI2B begin to fall or rise. This is shown from time T41 to time T45.

[0128] At time T41, signals SI1 and SI2 change from high level to low level. It begins. Note that signal SI1B is a signal inverted in logic from signal SI1, and signal SI Since 2B is the inverted logic of signal SI2, we will omit its explanation.

[0129] In the semiconductor device 40, transistors 41, 42, and 46 are included. Furthermore, transistor 47 begins to change from a conductive state to a non-conductive state, and the capacitive element C41 Due to capacitive coupling by the capacitive element C42, the signal SO1 is at a low level (low power supply potential VSS). The potential becomes lower than ). Also, transistors 43 and 44 are in a non-conductive state. As it changes from a conductive state to a conductive state, the potential of node N41 rises from a low level, and the transient Since terminal 45 becomes conductive, the potential of signal SO1 then begins to rise. Capacitive element C Due to capacitive coupling by 43, as the potential of signal SO1 rises, the potential of node N41 also rises. The potential of signal SO1 rises above the power supply potential VDD, and becomes equal to the high power supply potential VDD. It will rise.

[0130] In semiconductor device 50, transistor 51, transistor 52, transistor 56, Furthermore, transistor 57 begins to change from a conductive state to a non-conductive state, and the capacitive element C51 Due to capacitive coupling by the capacitive element C52, the SO2 signal will be at a potential lower than the low level. Furthermore, transistors 53 and 54 change from a non-conductive state to a conductive state. Therefore, the potential of node N51 rises from a low level, and transistor 55 becomes conductive. Therefore, the potential of the SO2 signal then begins to rise. Capacitive coupling by capacitive element C53 Therefore, as the potential of the SO2 signal rises, the potential of node N51 exceeds the high power supply potential VDD. The voltage rises until the potential of the SO2 signal becomes equal to the high power supply potential VDD.

[0131] At time T42, signal SI1 begins to change from a low level to a high level, and signal SI 2 remains at a low level.

[0132] In the semiconductor device 40, transistors 42 and 47 are in a non-conductive state. The circuit begins to change to a conductive state, but transistors 41 and 46 remain in a non-conductive state. It remains in that state. Also, transistor 43 begins to change from a conductive state to a non-conductive state, Transistor 44 remains in a conducting state. Therefore, the potential of node N41 is high. The signal SO1 remains at its high power supply potential VDD.

[0133] In the semiconductor device 50, transistors 52 and 57 are in a non-conductive state. However, transistors 51 and 56 change from a non-conductive state to a conductive state. It begins to change. Also, transistor 54 remains in a conducting state, but transistor 53 The state begins to change from conductive to non-conductive. Therefore, the potential of node N51 is high. As the voltage decreases, the potential of the SO2 signal drops from the high power supply potential VDD to the low power supply potential VSS.

[0134] At time T43, signal SI1 begins to change from high level to low level, signal SI 2 begins to change from a low level to a high level.

[0135] In the semiconductor device 40, transistors 42 and 47 are in a conductive state. As they begin to change to a non-conductive state, transistors 41 and 46 move from the non-conductive state. It begins to change to a conductive state. Also, transistor 43 changes from a non-conductive state to a conductive state. Initially, transistor 44 begins to change from a conductive state to a non-conductive state. Therefore, the node The potential of N41 remains at a high level, and the potential of signal SO1 remains at the high power supply potential VDD. That is the case.

[0136] In the semiconductor device 50, transistors 51 and 56 are in a conductive state. As they begin to change to a non-conductive state, transistors 52 and 57 move from a non-conductive state. It begins to change to a conductive state. Also, transistor 53 changes from a non-conductive state to a conductive state. Initially, transistor 54 begins to change from a conductive state to a non-conductive state. Therefore, the node The potential of N51 remains at a low level, and the potential of signal SO2 remains at the low power supply potential VSS. That is the case.

[0137] At time T44, signal SI1 begins to change from a low level to a high level, and signal SI 2 remains at a high level.

[0138] In the semiconductor device 40, transistors 42 and 47 are in a non-conductive state. As the circuit begins to change to a conductive state, transistors 41 and 46 remain in a conductive state. Furthermore, transistor 43 begins to change from a conductive state to a non-conductive state, and the transistor Node 44 remains in a non-conductive state. Therefore, the potential of node N41 decreases from a high level. The potential of signal SO1 decreases from the high power supply potential VDD to the low power supply potential VSS.

[0139] In the semiconductor device 50, transistors 51 and 56 are in a non-conductive state. Then it begins to change to a conductive state, and transistors 52 and 57 remain in a conductive state. Yes. Also, transistor 53 begins to change from a conductive state to a non-conductive state, and the transistor 54 remains in a non-conductive state. Therefore, the potential of node N51 remains at a low level. Therefore, the potential of the SO2 signal remains at the low power supply potential VSS.

[0140] At time T45, signals SI1 and SI2 change from high level to low level. It begins. The changes in signals SI1 and SI2 at time T45 are similar to those at time T41. Therefore, the explanation will be omitted.

[0141] As described above, the semiconductor device 40 has signals SI1, SI2, SI1B, and SI When 2B is input, semiconductor device 40 outputs signal SO1. That is, semiconductor device 40 It also functions as a NAND circuit. Furthermore, the semiconductor device 50 has signals SI1 and S When I2, signal SI1B, and signal SI2B are input, the semiconductor device 50 outputs signal SO2. In other words, the semiconductor device 50 has the function of a NOR circuit.

[0142] <Example of semiconductor device configuration> Semiconductor devices 40 and 50 are semiconductor devices 30 having two semiconductor devices 10. Similarly, they can be used in combination.

[0143] For example, semiconductor device 40 is represented by the symbol shown in Figure 9A, and semiconductor device 50 is shown in Figure 9B. We will represent these using symbols, and then explain examples of how to combine them.

[0144] Figure 9A is a diagram showing the symbols of semiconductor device 40, including the wiring VSS used for input and output. _IN, wiring VDD_IN, input terminal SI1_IN, input terminal SI2_IN, input terminal S I1B_IN, input terminal SI2B_IN, and output terminal SO1_OUT are shown. Yes, they are.

[0145] Figure 9B is a diagram showing the symbols of semiconductor device 50, including the wiring VSS used for input and output. _IN, wiring VDD_IN, input terminal SI1_IN, input terminal SI2_IN, input terminal S I1B_IN, input terminal SI2B_IN, and output terminal SO2_OUT are shown. Yes, they are.

[0146] Figure 10A is a block diagram showing an example configuration of a semiconductor device 60. The semiconductor device 60 is a semiconductor It has a main unit 40 and a semiconductor device 50. The semiconductor device 40 and the semiconductor device 50 are The output potential or signal is indicated using an arrow placed along the extension of the wiring.

[0147] In semiconductor device 60, the input terminal SI1_IN of semiconductor device 40 receives the signal SI1 When input is received, signal SI2 is input to input terminal SI2_IN, and input terminal SI1B_IN Signal SI1B is input to the input terminal SI2B_IN, and signal SI2B is input to the output terminal. Signal SO1 is output from the power terminal SO1_OUT. Meanwhile, in semiconductor device 60, The signal SI1B is input to the input terminal SI1_IN of the semiconductor device 50, and the input terminal S Signal SI2B is input to I2_IN, and signal SI1 is input to input terminal SI1B_IN. The signal SI2 is input to the input terminal SI2B_IN, and the output terminal SO2_OUT The signal SO1B is output.

[0148] Next, Figure 11 shows a timing chart illustrating an example of the operation of the semiconductor device 60. Signal SI1 For signals SI2, SI1B, SI2B, and SO1, see the tie shown in Figure 8. This is the same as the timing chart, and Figure 11 also includes a timing chart for signal SO1B. It is shown.

[0149] The semiconductor device 50 of the semiconductor device 60 has signals SI1 and SI1B, and signals SI2 and signal SI2B are in the opposite direction to semiconductor device 50 as explained in the timing chart of Figure 8. The signal SI1B is input. Therefore, the semiconductor device 50 of semiconductor device 60 receives the signal SI1B. When the signal SI2B is low level, a high-level signal S is output from the output terminal SO2_OUT. It outputs O1B. That is, signal SO1B is the signal obtained by inverting the logic of signal SO1. ru.

[0150] Figure 10B is a block diagram showing an example configuration of the semiconductor device 70. The semiconductor device comprises a semiconductor device 50 and a semiconductor device 40. The input and output potentials or signals are indicated using arrows placed along the extensions of the wiring.

[0151] In semiconductor device 70, the input terminal SI1_IN of semiconductor device 50 receives the signal SI1 When input is received, signal SI2 is input to input terminal SI2_IN, and input terminal SI1B_IN Signal SI1B is input to the input terminal SI2B_IN, and signal SI2B is input to the output terminal. The signal SO2 is output from the power terminal SO2_OUT. Meanwhile, in semiconductor device 70, The signal SI1B is input to the input terminal SI1_IN of the semiconductor device 40, and the input terminal S Signal SI2B is input to I2_IN, and signal SI1 is input to input terminal SI1B_IN. The signal SI2 is input to the input terminal SI2B_IN, and the output terminal SO1_OUT The signal SO2B is output.

[0152] Next, Figure 12 shows a timing chart illustrating an example of the operation of the semiconductor device 70. Signal SI1 For signals SI2, SI1B, SI2B, and SO2, see the tie shown in Figure 8. This is the same as the timing chart, and Figure 12 also includes a timing chart for signal SO2B. It is shown.

[0153] The semiconductor device 40 of the semiconductor device 70 has signals SI1 and SI1B, and signals SI2 and signal SI2B are in the opposite direction to semiconductor device 40 as explained in the timing chart of Figure 8. The signal SI1B is input. Therefore, the semiconductor device 40 of semiconductor device 70 receives the signal SI1B. When the signal SI2B is at a high level, a low-level signal S is output from the output terminal SO1_OUT. It outputs O2B. That is, signal SO2B is a signal inverted in logic from signal SO2. ru.

[0154] As described above, the semiconductor device 60 has signals SI1, SI2, SI1B, and SI2 B is input and outputs signals SO1 and SO1B. Also, the semiconductor device 70 sends Signal SI1, signal SI2, signal SI1B, signal SI2B are input, and signal SO2 and signal It outputs SO2B. Signal SO1B is the inverted logic of signal SO1, and signal S O2B is a signal inverted in logic from the SO2 signal.

[0155] In other words, semiconductor devices 30, 60, and 70 are electrically connected to one another. It is possible to use semiconductor device 30, semiconductor device 60, and semiconductor device 70. This allows for the construction of general-purpose logic circuits.

[0156] This embodiment may be implemented in appropriate combination with other embodiments described herein. It is possible.

[0157] (Embodiment 3) In this embodiment, the transistors constituting the semiconductor device 10 described in the above embodiment are used. , transistors constituting semiconductor device 20, transistors constituting semiconductor device 40, OS transistors, which can be used in transistors constituting the semiconductor device 50. An example of its configuration will be explained. Note that the OS transistor is a thin-film transistor and is stacked. Since it can be provided in this way, in this embodiment, SiT formed on a single crystal silicon substrate This section describes an example of a semiconductor device configuration in which an OS transistor is placed above a transistor.

[0158] <Example of semiconductor device configuration> The semiconductor device shown in Figure 13 includes transistor 300, transistor 500, and a capacitance element. It has a child 600. Figure 14A is a cross-sectional view of transistor 500 in the channel length direction. Figure 14B is a cross-sectional view of transistor 500 in the channel width direction, and Figure 14C is a cross-sectional view of transistor 500 This is a cross-sectional view of the STA300 in the channel width direction.

[0159] Transistor 500 is a transistor (OS transistor) having a metal oxide in the channel formation region. It is a transistor. Transistor 500 is a transistor that can be operated by applying a high voltage between its source and drain. It can do so, the off-current does not increase easily even in high-temperature environments, and the ratio of on-current to off-current remains constant even in high-temperature environments. Because it has the characteristic of being large, in the above embodiment, this is used for semiconductor device 10, semiconductor By using it in the device 20, semiconductor device 40, and semiconductor device 50, the semiconductor device This allows for the creation of a highly reliable semiconductor device.

[0160] The semiconductor device described in this embodiment, as shown in Figure 13, includes a transistor 300, a tra It has a transistor 500 and a capacitive element 600. Transistor 500 is transistor 3 Located above 00, the capacitive element 600 is connected to transistors 300 and 50. It is located above 0.

[0161] The transistor 300 is mounted on the substrate 311 and consists of a conductor 316, an insulator 315, and substrate 3 A semiconductor region 313 consisting of part of 11, and a region that functions as a source region or drain region. It has a low-resistance region 314a and a low-resistance region 314b.

[0162] As shown in Figure 14C, transistor 300 is located on the top surface and channel of semiconductor region 313. The sides in the width direction are covered by the conductor 316 via the insulator 315. In this way, By making the ZISTA 300 a Fin type, the effective channel width is increased. The ON characteristics of the transistor 300 can be improved. Also, the contribution of the electric field of the gate electrode. This allows for an increase in the off-peak characteristics of transistor 300. .

[0163] Note that transistor 300 can be either a p-channel or n-channel type.

[0164] The region where the channel of the semiconductor region 313 is formed, the region near it, the source region, or the do In the low-resistance region 314a and low-resistance region 314b, which are rain regions, silico It is preferable that the semiconductor contains semiconductors such as silicon-based semiconductors, and it is preferable that it contains single-crystal silicon. Alternatively, Ge (germanium), SiGe (silicon germanium), GaAs (galvanium) It may also be formed from materials containing arginine, GaAlAs (gallium aluminum arsenide), etc. By applying stress to the crystal lattice and changing the lattice spacing, silicon with controlled effective mass is produced. The configuration used may also be used. Alternatively, by using GaAs and GaAlAs, etc., the transient TA300 is HEMT (High Electron Mobility Transit) You can also use "tor)".

[0165] Low-resistance regions 314a and 314b are semiconductor regions applied to semiconductor region 313. In addition to the main material, elements that impart n-type conductivity, such as arsenic and phosphorus, or p-type conductivity, such as boron. It contains elements that impart conductivity.

[0166] The conductor 316, 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.

[0167] Furthermore, since the work function is determined by the material of the conductor, by changing the material of the conductor, The Vth of the transistor can be adjusted. Specifically, titanium nitride or titanium nitride can be used as the conductor. It is preferable to use materials such as tar. Furthermore, in order to achieve both conductivity and embedding properties It is preferable to use a conductive material with layers of metallic materials such as tungsten or aluminum. In particular, the use of tungsten is preferable in terms of heat resistance.

[0168] Note that the transistor 300 shown in Figure 13 is just one example, and its structure is not limited to that of the circuit configuration. Depending on the driving method, an appropriate transistor should be used.

[0169] The transistor 300 is covered by insulators 320, 322, 324, and insulation. The bodies 326 are arranged in a series of stacked units.

[0170] As insulators 320, 322, 324, and 326, 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.

[0171] The insulator 322 smooths out the step created by the transistor 300 and the like located below it. It may also function as a planarizing film that flattens. For example, the upper surface of the insulator 322 is flat Chemical mechanical polishing (CMP) is used to improve durability. The surface may be flattened by a planarization process such as the polishing method.

[0172] Furthermore, the insulator 324 receives transistors from the substrate 311 or transistors 300, etc. A barrier film is used in the region where the TA500 is provided to prevent the diffusion of hydrogen and impurities. It is preferable that they be present.

[0173] 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 300. It is preferable to have one. Specifically, a membrane that suppresses hydrogen diffusion is one that minimizes hydrogen desorption. It will form a membrane.

[0174] The amount of hydrogen desorbed can be determined, for example, by thermal desorption gas analysis (TDS analysis). Analysis can be performed using methods such as spectroscopy. The amount of hydrogen desorption from insulator 324 was determined by TDS analysis when the film surface temperature was 50°C to 50°C. In the range of 0°C, the amount of desorption converted to hydrogen atoms is converted to the area of ​​insulator 324. 10 x 10 15 atoms / cm 2 The following is preferably 5 × 10 15 atoms / cm 2 The following is acceptable.

[0175] Furthermore, it is preferable that the dielectric constant of the insulator 326 is lower than that of the insulator 324. For example, insulation The relative permittivity of body 326 is preferably less than 4, and more preferably less than 3. Also, for example, insulator 3 The relative permittivity of 26 is preferably 0.7 times or less the relative permittivity of the insulator 324, and preferably 0.6 times or less. More preferable. By using a material with a low dielectric constant as the interlayer film, the parasitic capacitance that occurs between the wiring is reduced. It can be reduced.

[0176] Furthermore, insulators 320, 322, 324, and 326 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. Furthermore, a conductor that functions as a plug or wiring has multiple structures. 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.

[0177] The materials for each plug and wiring (conductor 328, conductor 330, etc.) are metal materials. Conductive materials such as materials, alloy materials, metal nitride materials, or metal oxide materials are used in a single layer or It can be used in a layered configuration. Materials such as tungsten and molybdenum offer both heat resistance and conductivity. It is preferable to use a high melting point material, and it is preferable to use tungsten. Alternatively, It is preferable to form it with a low-resistance conductive material such as aluminum or copper. Low-resistance conductive material By using this method, wiring resistance can be reduced.

[0178] A wiring layer may be provided on the insulator 326 and the conductor 330. For example, as shown in Figure 13. The insulator 350, insulator 352, and insulator 354 are arranged in a stacked manner. Furthermore, a conductor 356 is formed in insulators 350, 352, and 354. The conductor 356 is a plug or wiring that connects to the transistor 300. It has the ability. The conductor 356 uses the same material as conductors 328 and 330. It can be established by doing so.

[0179] For example, insulator 350 has a barrier property against hydrogen, similar to insulator 324. 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 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0180] 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 300 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 structure is in contact with the insulator 350.

[0181] A wiring layer may be provided on the insulator 354 and the conductor 356. For example, as shown in Figure 13. Insulators 360, 362, and 364 are arranged in a stacked manner. Furthermore, a conductor 366 is formed on insulators 360, 362, and 364. Conductor 366 has the function of a plug or wiring. These can be provided using the same material as conductor 328 and conductor 330.

[0182] For example, insulator 360 has a barrier property against hydrogen, similar to insulator 324. 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 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0183] A wiring layer may be provided on the insulator 364 and the conductor 366. For example, as shown in Figure 13. Insulators 370, 372, and 374 are arranged in a stacked manner. Furthermore, a conductor 376 is formed in insulators 370, 372, and 374. Conductor 376 functions as a plug or wiring. These can be provided using the same material as conductor 328 and conductor 330.

[0184] For example, insulator 370 has a barrier property against hydrogen, similar to insulator 324. 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 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0185] A wiring layer may be provided on the insulator 374 and the conductor 376. For example, as shown in Figure 13... The insulators 380, 382, ​​and 384 are arranged in a stacked manner. Furthermore, a conductor 386 is formed on insulators 380, 382, ​​and 384. Conductor 386 functions as a plug or wiring. These can be provided using the same material as conductor 328 and conductor 330.

[0186] For example, insulator 380 has a barrier property against hydrogen, similar to insulator 324. 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 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0187] 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.

[0188] 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 bodies 516 be made of a material that has barrier properties against oxygen and hydrogen. stomach.

[0189] For example, the insulator 510 and the insulator 514 are connected to the substrate 311 or the transistor 30 Hydrogen and impurities do not diffuse from the region where 0 is set to the region where transistor 500 is set. It is preferable to use a film having such barrier properties. Therefore, similar to insulator 324. These materials can be used.

[0190] 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 transistor 500 and transistor 300. This is preferable. Specifically, a membrane that suppresses hydrogen diffusion is a membrane that releases less hydrogen. .

[0191] 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.

[0192] 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.

[0193] Furthermore, for example, the same material as the insulator 320 is used for insulators 512 and 516. It is possible to have it there. Also, by using a material with a relatively low dielectric constant as the interlayer film, it can prevent the formation of a barrier between the wiring. This can reduce parasitic capacitance. For example, as insulator 512 and insulator 516 Silicon oxide films and silicon oxide nitride films can be used.

[0194] Furthermore, insulators 510, 512, 514, and 516 contain a conductor 5 18, and a conductor (conductor 503) etc. that constitutes the transistor 500 are embedded. The conductor 518 is connected to the capacitive element 600 or the transistor 300. It functions as a wire or a conductor. Conductor 518 is connected to conductor 328 and conductor 3 It can be provided using the same materials as in 30.

[0195] 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 300 and Transistor 500 have barrier properties against oxygen, hydrogen, and water. In the layer, it can be separated, and hydrogen from transistor 300 to transistor 500 It can suppress diffusion.

[0196] A transistor 500 is provided above the insulator 516.

[0197] As shown in Figures 14A and 14B, transistor 500 is insulator 514 and insulator 5 A conductor 503 is positioned to be embedded in 16, and on top of the insulator 516 and the conductor 503 An insulator 520 is placed on top of the insulator 520, and an insulator 522 is placed on top of the insulator 5 An insulator 524 placed on 22, and an oxide 530a placed on the insulator 524 On top of oxide 530a, oxide 530b is placed, and on oxide 530b, spaced apart from each other. Conductors 542a and 542b are arranged in such a manner, and conductors 542a and 5 It is positioned on 42b and has an opening formed by overlapping between the conductor 542a and the conductor 542b. The insulator 580, the conductor 560 placed in the opening, the oxide 530b, and the conductor 542 a, conductor 542b, and insulator 580 and conductor 560, an insulator placed between them 550, oxide 530b, conductor 542a, conductor 542b, and insulator 580, It comprises an insulator 550 and an oxide 530c disposed between them.

[0198] Furthermore, as shown in Figures 14A and 14B, oxide 530a, oxide 530b, and conductor 54 It is preferable that the insulator 544 is placed between 2a and the conductor 542b and the insulator 580. It seems so. Also, as shown in Figures 14A and 14B, the conductor 560 is inside the insulator 550. A conductor 560a is provided therein, and is provided so as to be embedded inside the conductor 560a It is preferable to have a conductor 560b. Also, as shown in Figures 14A and 14B, The insulator 574 is placed on top of the insulator 580, the conductor 560, and the insulator 550. It is preferable.

[0199] In the following, oxides 530a, 530b, and 530c are grouped together. In some cases, it is referred to as oxide 530. Also, conductors 542a and 542b are grouped together. In some cases, it is referred to as conductor 542.

[0200] Furthermore, in transistor 500, oxidation occurs in the region where the channel is formed and in its vicinity. The following describes a configuration in which three layers of material 530a, oxide 530b, and oxide 530c are laminated. However, the present invention is not limited thereto. For example, a single layer of oxide 530b, oxidation Two-layer structure of substance 530b and oxide 530a, two-layer structure of oxide 530b and oxide 530c, Alternatively, a configuration with a stacked structure of four or more layers may be used. Furthermore, in transistor 500, Although the conductor 560 is shown as a two-layer laminated structure, the present invention is not limited thereto. For example, the conductor 560 may have a single-layer structure or a laminated structure of three or more layers. This is also fine. Furthermore, the transistor 500 shown in Figures 13, 14A, and 14B is just one example, and The structure is not limited to this; an appropriate transistor can be used depending on the circuit configuration and driving method.

[0201] Here, conductor 560 functions as the gate electrode of the transistor, and conductor 542a and The conductor 542b functions as either a source electrode or a drain electrode, respectively. In addition, the conductor 560 is connected to the opening of the insulator 580, and to the conductors 542a and 542b. It is formed so as to be embedded in the sandwiched region. Conductor 560, Conductor 542a and Conductor The arrangement of the electric element 542b is selected in a self-aligned manner with respect to the opening of the insulator 580. In transistor 500, the gate electrode is connected between the source electrode and the drain electrode, self It can be arranged in a consistent manner. Therefore, the conductor 560 is provided with a margin for alignment. Since it can be formed without any additional steps, the occupied area of ​​transistor 500 can be reduced. This makes it possible to miniaturize and highly integrate semiconductor devices.

[0202] 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.

[0203] The conductor 560 may function as the first gate (also called the top gate) electrode. Furthermore, the conductor 503 functions as a second gate (also called a bottom gate) electrode. In some cases, the potential applied to conductor 503 is changed to the potential applied to conductor 560. By changing it independently, without linking it to the other parameters, the Vth of transistor 500 can be controlled. This can be done. In particular, by applying a negative potential to the conductor 503, the transistor 500 By making Vth greater than 0V, it becomes possible to reduce the off-current. Therefore, conductivity Applying a negative potential to body 503 is more effective than not applying one to the conductor 560. The drain current when the potential is 0V can be reduced.

[0204] 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-forming region. In this specification, the first gate electrode and the second The structure of a transistor where the electric field of the gate electrode electrically surrounds the channel formation region. This is called a surrounded channel (S-channel) structure.

[0205] Furthermore, in this specification, the S-channel structure is defined as the source electrode and the drain electrode. The sides and periphery of the oxide 530 in contact with the conductors 542a and 542b, which function as such. The edges have the characteristic of being I-shaped, just like the channel-forming region. Also, conductor 542 The sides and periphery of the oxide 530 in contact with a and the conductor 542b are in contact with the insulator 544. Therefore, it can be type I, similar to the channel-forming region. In this specification, type I This can be treated similarly to high-purity genuine materials, as will be described later. Furthermore, as disclosed in this specification, etc. The S-channel structure is different from the Fin-type and Planar-type structures. By adopting a NEL structure, resistance to short channel effects is increased, or in other words, short channel This allows for the creation of a transistor that is less susceptible to the Nell effect.

[0206] 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. It has been done.

[0207] Insulators 520, 522, 524, and 550 are used as gate insulating films. It has the function of being functional.

[0208] 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. In other words, the insulator 524 contains excess oxygen. It is preferable that such an insulator containing excess oxygen is brought into contact with oxide 530. By providing this, oxygen deficiency in the oxide 530 is reduced, and the reliability of the transistor 500 is improved. It can improve sexual performance.

[0209] As the insulator having an excess oxygen region, specifically, an oxide material in which some oxygen is desorbed by heating is preferably used. The oxide that desorbs oxygen by heating means that in TDS analysis , the desorption amount of oxygen in terms of oxygen atoms is 1.0×10 18 atoms / cm 3 or more, preferably 1.0×10 19 atoms / cm 3 or more, more preferably 2.0×10 19 a toms / cm 3 or more, or 3.0×10 20 atoms / cm<于 3 or more, which is an oxide film is. Note that the surface temperature of the film during the above TDS analysis is preferably in the range of 100°C or more and 700°C or less, or 100°C or more and 400°C or less.

[0210] Also, when the insulator 524 has an excess oxygen region, the insulator 522 preferably has a function of suppressing the diffusion of oxygen (for example, oxygen atoms, oxygen molecules, etc.) (it is difficult for the above oxygen to permeate).

[0211] By the insulator 522 having a function of suppressing the diffusion of oxygen and impurities, the oxygen possessed by the oxide 530 does not diffuse to the insulator 520 side, which is preferable. Also, the conductor 503 can be suppressed from reacting with the oxygen possessed by the insulator 524 and the oxide 530.

[0212] The insulator 522 is, for example, an insulator containing aluminum oxide, hafnium oxide, tantalum oxide, zirconium oxide, lead zirconate titanate (PZT), strontium titanate (SrTiO3) or (Ba,Sr)TiO3 (BST), etc., is used in a single layer or a laminate. This is preferable. As transistors become smaller and more integrated, the gate insulating film becomes thinner. This can lead to problems such as leakage current. An insulator that functions as a gate insulating film. By using high-k material, the physical film thickness is maintained while the gate during transistor operation is maintained. This makes it possible to reduce the potential.

[0213] In particular, it has the function of suppressing the diffusion of impurities and oxygen (the above oxygen does not easily permeate). ) Insulators containing oxides of aluminum and hafnium, or both, which are insulating materials. It is best to use a body. An insulating material containing an oxide of either or both aluminum and hafnium. As a body, aluminum oxide, hafnium oxide, aluminum and hafnium-containing acids It is preferable to use alloys (hafnium aluminate, etc.). When an insulator 522 is formed, the insulator 522 prevents the release of oxygen from the oxide 530 and tra As a layer to suppress the incorporation of impurities such as hydrogen from the peripheral area of ​​the radiator 500 into the oxide 530 It works.

[0214] 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.

[0215] 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 A laminated insulator 520 with a high dielectric constant can be obtained.

[0216] Furthermore, the insulators 520, 522, and 524 have a laminated structure of two or more layers. It is also acceptable to have a laminated structure made of the same material, or a structure made of different materials. A layered structure is also acceptable.

[0217] The transistor 500 is formed in the oxide 530 including the channel formation region as an oxide semiconductor. It is preferable to use a metal oxide that can perform the function. For example, as oxide 530, In-MZ n oxide (element M is aluminum, gallium, yttrium, copper, vanadium, beryllium) Um, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, rancid Tan, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium It is preferable to use one or more metal oxides selected from the above. Also, oxide 5 For 30, In-Ga oxide or In-Zn oxide may be used.

[0218] Furthermore, it is preferable to use a metal oxide with a low carrier density for the transistor 500. When lowering the carrier density of the metal oxide, the concentration of impurities in the metal oxide is reduced. Therefore, it is sufficient to lower the defect level density. In this specification, the impurity concentration is low and the defect level A low ion density is referred to as high-purity intrinsic or substantially high-purity intrinsic. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, and nickel. , silicone, etc.

[0219] In particular, the hydrogen contained in metal oxides reacts with the oxygen bonded to the metal atoms to form water, Oxygen vacancies can form in metal oxides. If defects are present, the transistor may exhibit normally-on characteristics. Furthermore, A defect where hydrogen fills an oxygen vacancy functions as a donor, generating electrons, which act as carriers. Furthermore, some of the hydrogen combines with the metal atom, and oxygen combines with the electron carrier. This can generate transients. Therefore, transients using metal oxides that contain a lot of hydrogen are produced. Ta tends to exhibit normally-on characteristics.

[0220] Defects where hydrogen fills an oxygen vacancy can function as donors for metal oxides. However, It is difficult to quantitatively evaluate the defect in question. Therefore, in metal oxides, donor In some cases, the evaluation is based on carrier density rather than concentration. Therefore, in this specification, metal acids The parameters of the compound are not the donor concentration, but rather the assumption that no electric field is applied. Rear density may be used. In other words, the "carrier density" as described herein, etc., refers to "donor It can sometimes be rephrased as "concentration."

[0221] Therefore, when using metal oxides in oxide 530, the amount of hydrogen in the metal oxide should be reduced as much as possible. It is preferable that this is done. Specifically, in metal oxides, secondary ion mass spectrometry ( SIMS (Secondary Ion Mass Spectrometry) The hydrogen concentration obtained is 1 × 10 20 atoms / cm 3 Less than 1 × 10 19 a toms / cm 3 Less than 5x10 18atoms / cm 3 Less than, even better Mashiku is 1 x 10 18 atoms / cm 3 It shall be less than. Impurities such as hydrogen shall be sufficiently reduced. By using a metal oxide in the channel formation region of a transistor, stable electrical characteristics can be achieved. It can be granted.

[0222] Furthermore, when a metal oxide is used for oxide 530, the metal oxide carrier in the channel formation region The density is 1 × 10⁻⁶ 18 cm -3 The following is preferable: 1 × 10 17 cm -3 less than It is more preferable that it be 1 × 10 16 cm -3 It is even more preferable that it be less than 1 ×10 13 cm -3 It is even more preferable that it be less than 1 × 10 12 cm -3 Less than It is even more preferable that the lower limit of the carrier density of the metal oxide in the channel formation region is Therefore, there are no particular limitations, but for example, 1 x 10 -9 cm -3 It can be done this way.

[0223] Furthermore, when a metal oxide is used for oxide 530, the conductor 542 (conductor 542a, and When the conductor 542b) and the oxide 530 come into contact, the oxygen in the oxide 530 enters the conductor 54 It may diffuse into 2, causing the conductor 542 to oxidize. When the conductor 542 oxidizes, the conductivity There is a high probability that the conductivity of body 542 will decrease. Note that oxygen in oxide 530 is present in conductor 542. To describe the diffusion into the oxide 530, it can be rephrased as the conductor 542 absorbing oxygen from the oxide 530. It is possible.

[0224] Furthermore, the oxygen in oxide 530 is conductor 542 (conductor 542a and conductor 542b) By diffusion, the conductor 542a and oxide 530b, and the conductor 542b and A different layer may be formed between the oxide 530b and the conductor 542. Because it contains a large amount of oxygen, this different layer is presumed to have insulating properties. At this time, conductor 542 The three-layer structure of the aforementioned heterogeneous layer and oxide 530b is a three-layer structure consisting of metal-insulator-semiconductor. It can be considered a structure, and MIS (Metal-Insulator-Semiconductor) It is sometimes called a ctor structure, or a diode junction structure that mainly consists of MIS structures. ru.

[0225] Furthermore, the above-mentioned heterogeneous layer is not limited to being formed between the conductor 542 and the oxide 530b. For example, when a different layer is formed between the conductor 542 and the oxide 530c, or when the conductor 54 The fields formed between 2 and oxide 530b, and between conductor 542 and oxide 530c There is a match.

[0226] Furthermore, the metal oxide that functions as a channel-forming region in oxide 530 is bandgable It is preferable to use a device with a voltage of 2 eV or higher, preferably 2.5 eV or higher. By using a metal oxide with a large band gap, the off-current of the transistor can be reduced. It is possible.

[0227] In addition, semiconductor materials that can be used for oxide 530 are not limited to the metal oxides mentioned above. i. Oxide 530 is a semiconductor material with a band gap (in zero-gap semiconductors) Semiconductor materials (that do not contain semiconductor materials) may also be used. For example, semiconductors of elemental silicon, gallium arsenide, etc. Compound semiconductors such as um, and layered materials that function as semiconductors (atomic layer materials, two-dimensional materials, etc.) It is preferable to use materials such as (also known as) as semiconductor materials. In particular, layered materials that function as semiconductors The material is suitable for use as a semiconductor material.

[0228] Here, in this specification, etc., "layered material" is a general term for a group of materials having a layered crystalline structure. The layered crystalline structure is formed by layers created by covalent and ionic bonds, such as van der Wain. It is a structure in which layers are attached via weaker bonds than covalent or ionic bonds, such as the Rus force. Layered materials have high electrical conductivity within a unit layer, meaning they have high two-dimensional electrical conductivity. By using a material that functions as a semiconductor and has high two-dimensional electrical conductivity in the channel formation region. This allows us to provide transistors with high on-current.

[0229] Layered materials include graphene, silicene, and chalcogenides. It is a compound containing chalcogens. Furthermore, chalcogens are a general term for elements belonging to Group 16. It contains oxygen, sulfur, selenium, tellurium, polonium, and livermorium. Examples of cogenides include transition metal chalcogenides and group 13 chalcogenides.

[0230] For example, a transition metal chalcogenide that functions as a semiconductor can be used as oxide 530. This is preferable. Specifically, as transition metal chalcogenides applicable as oxide 530, These are molybdenum sulfide (typically MoS2) and molybdenum selenide (typically MoSe 2) Molybdenum telluride (typically MoTe2), tungsten sulfide (typically WS) 2) Tungsten selenide (typically WSe2), tungsten tellurium (typically WTe2), hafnium sulfide (typically HfS2), hafnium selenide (typically HfSe2), zirconium sulfide (typically ZrS2), zirconium selenide (typically Examples include ZrSe2.

[0231] Oxide 530 has oxide 530a beneath oxide 530b, so oxide 530a Furthermore, it is possible to suppress the diffusion of impurities from the structure formed below to oxide 530b. It can be done. Also, by having oxide 530c on oxide 530b, oxide 530c is better than The diffusion of impurities from the structure formed above to oxide 530b can be suppressed. .

[0232] 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. Oxide 530c is a metal oxide that can be used in oxide 530a or oxide 530b. The object can be used.

[0233] Furthermore, the energy at the lower end of the conduction band of oxide 530a and oxide 530c is It is preferable that the energy of b is higher than the energy of the lower end of the conduction band. In other words, oxide The electron affinity of 530a and oxide 530c is smaller than the electron affinity of oxide 530b. It is preferable.

[0234] Here, at the joint of oxide 530a, oxide 530b, and oxide 530c, The energy levels at the lower end of the guide band change smoothly. In other words, oxide 530a, oxide The energy levels at the lower end of the conduction band at the junction of 530b and oxide 530c are continuous. It can also be said that it undergoes a gradual change or continuous bonding. In order to do this, oxide 5 At the interface between 30a and oxide 530b, and at the interface between oxide 530b and oxide 530c It is desirable to lower the defect level density of the mixed layer that is formed.

[0235] Specifically, oxide 530a and oxide 530b, and oxide 530b and oxide 530c, By having a common element other than the primary element (as the main component), a mixed layer with a low defect level density is formed. It is possible. For example, if oxide 530b is In-Ga-Zn oxide, then oxide 5 As 30a and oxide 530c, In-Ga-Zn oxide, Ga-Zn oxide, oxide Using gallium or similar materials would be a good idea.

[0236] In this case, the main carrier pathway is oxide 530b. Oxide 530a, oxide 53 By configuring 0c as described above, the interface between oxide 530a and oxide 530b, and oxidation The defect level density at the interface between material 530b and oxide 530c can be reduced. Therefore, the influence of interfacial scattering on carrier conduction is reduced, and transistor 500 has high On-current can be obtained.

[0237] On the oxide 530b, there is a conductor 542 that functions as a source electrode and a drain electrode. Conductors 542a and 542b are provided. As for the conductor 542, aluminum nium, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum, tung Stainless steel, hafnium, vanadium, niobium, manganese, magnesium, zirconium, be Selected from lylium, indium, ruthenium, iridium, strontium, and lanthanum. A metal element, or an alloy containing the above-mentioned metal elements, or a combination of the above-mentioned metal elements It is preferable to use alloys such as tantalum nitride, titanium nitride, and tungsten. , nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, lutein oxide nium, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel It is preferable to use oxides containing tar. Also, tantalum nitride, titanium nitride, titanium Nitrides containing aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, Ruthenium nitride, oxides containing strontium and ruthenium, and oxides containing lanthanum and nickel. Oxides are conductive materials that are resistant to oxidation, or materials that maintain their conductivity even when absorbing oxygen. Therefore, it is preferable.

[0238] Furthermore, as shown in Figure 14A, at the interface of oxide 530 with conductor 542 and in its vicinity, When a low-resistance region is formed, region 543 (region 543a and region 543b) There is such a thing. In this case, region 543a functions as either the source region or the drain region. Region 543b functions as either the source region or the drain region. Also, region 543 A channel-forming region is formed in the area sandwiched between region a and region 543b.

[0239] By providing the conductor 542 in contact with the oxide 530, the oxygen concentration in region 543 It may be reduced. Also, in region 543, the metal contained in the conductor 542 and the oxide 530 A metal compound layer containing the components may be formed. In such cases, region 543 As the carrier density increases, region 543 becomes a low-resistance region.

[0240] The insulator 544 is provided so as to cover the conductor 542, thereby suppressing oxidation of the conductor 542. At this time, the insulator 544 covers the side surface of the oxide 530 and is arranged to be in contact with the insulator 524. I don't mind being kicked.

[0241] Insulator 544 includes hafnium, aluminum, gallium, yttrium, and zirconium. Tungsten, titanium, tantalum, nickel, germanium, or magnesium One or more metal oxides selected from the above can be used.

[0242] 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, hafnium Um aluminate has higher heat resistance than hafnium oxide film. Therefore, in subsequent processes... It is preferable because it does not crystallize easily during heat treatment. Furthermore, the conductor 542 has oxidation resistance. If the material does not experience a significant decrease in conductivity even when absorbing oxygen, the insulator 544 is essential. This is not the correct configuration. The design should be adjusted as needed based on the desired transistor characteristics.

[0243] Insulator 550 functions as a gate insulating film. Insulator 550 is inside oxide 530c. It is preferable to place it in contact with the (top and side) surfaces. The insulator 550 is heated by oxygen It is preferable to form it using an insulator that emits oxygen. For example, in TDS analysis, oxygen The amount of oxygen removed in terms of offspring is 1.0 × 10⁻⁶. 18 atoms / cm 3 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 in the range of 100°C to 700°C. It is preferable.

[0244] Specifically, silicon oxide, silicon oxide nitride, silicon nitride oxide, and silicon oxide containing excess oxygen. Silicon oxide, fluorinated silicon oxide, carbon-added silicon oxide, carbon and Nitrogen-added silicon oxide and porous silicon oxide can be used. In particular, Silicon oxide and silicon oxide-nitride are preferred because they are stable to heat.

[0245] An insulator that releases oxygen upon heating is designated as insulator 550 and is brought into contact with the upper surface of oxide 530c. By providing this, the oxide 530b is transmitted from the insulator 550 through the oxide 530c. It can effectively supply oxygen to the channel-forming region. Also, similar to insulator 524. Preferably, the concentration of impurities such as water or hydrogen in the insulator 550 is reduced. The thickness of the edge body 550 is preferably between 1 nm and 20 nm.

[0246] Furthermore, in order to efficiently supply excess oxygen from the insulator 550 to the oxide 530, A metal oxide may be provided between the body 550 and the conductor 560. The metal oxide is an insulator. It is preferable to suppress oxygen diffusion from 550 to the conductor 560. By providing a metal oxide, the diffusion of excess oxygen from the insulator 550 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.

[0247] The conductor 560, which functions as the first gate electrode, has a two-layer structure in Figures 14A and 14B. Although shown, it may be a single-layer structure or a laminated structure of three or more layers.

[0248] 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 (one of) the conductive material. Conductor 5 Because 60a has the function of suppressing oxygen diffusion, the oxygen contained in the insulator 550 This suppresses the oxidation of the conductor 560b and the resulting decrease in conductivity. Examples of conductive materials that have the function of suppressing dispersion include tantalum, tantalum nitride, and luteinizing agent. It is preferable to use nium or ruthenium oxide.

[0249] 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 done as a laminated structure of titanium or titanium nitride and the above-mentioned conductive material. stomach.

[0250] The insulator 580 is provided on the conductor 542 via the insulator 544. It is preferable to have an excess oxygen region. For example, as the insulator 580, silicon oxide, Silicon oxide nitride, silicon nitride, silicon nitride, fluorine-added silicon oxide, Carbon-doped silicon oxide, carbon and nitrogen-doped silicon oxide, porous acids It is preferable to have silicon oxide or resin. In particular, silicon oxide and nitrile oxide Silicon oxides are preferred because they are thermally stable. In particular, silicon oxide and porous silicon oxides are preferred. Silicon is preferred because it can easily form an excess oxygen region in a later process.

[0251] The insulator 580 preferably has an excess oxygen region. By providing the edge 580 in contact with the oxide 530c, the oxygen in the insulator 580 is removed from the oxide. It can be efficiently supplied to oxide 530 through 530c. Note that insulator 58 It is preferable that the concentration of impurities such as water or hydrogen in the solution is reduced.

[0252] 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.

[0253] 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.

[0254] 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 550. It is preferable that it be provided in contact with the insulator 574. This allows for the creation of excess oxygen regions in the insulators 550 and 580. Oxygen can be supplied to the oxide 530 from the excess oxygen region.

[0255] 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.

[0256] 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.

[0257] 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.

[0258] Furthermore, openings formed in insulators 581, 574, 580, and 544 Conductors 540a and 540b are placed in the opening. 40b is provided opposite the conductor 560, with the conductor 540a and conductor 540b in between. This has the same configuration as conductors 546 and 548, which will be described later.

[0259] An insulator 582 is provided on the insulator 581. The insulator 582 is resistant to oxygen and hydrogen. Therefore, it is preferable to use a barrier material. The same material as body 514 can be used. For example, insulator 582 can be made of aluminum oxide. It is preferable to use metal oxides such as um, hafnium oxide, and tantalum oxide.

[0260] 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.

[0261] Furthermore, an insulator 586 is provided on the insulator 582. The insulator 586 is insulator 3 The same materials as in 20 can be used. Additionally, a material with a relatively low dielectric constant can be used as the interlayer film. This reduces parasitic capacitance between wires. For example, as insulator 586 Silicon oxide films and silicon oxide nitride films can be used.

[0262] 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.

[0263] 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 Rangista 300. Conductor 546, The conductor 548 is provided using the same material as the conductors 328 and 330. It is possible.

[0264] Next, a capacitive element 600 is provided above the transistor 500. 00 comprises a conductor 610, a conductor 620, and an insulator 630.

[0265] 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.

[0266] 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.

[0267] In Figure 13, the conductors 612 and 610 are shown as single-layer structures, but the structure The structure is not limited to a single layer, and may also be a laminated structure of two or more layers. For example, a conductor with barrier properties and a conductive A conductor with barrier properties between a highly conductive material and a highly conductive material. A conductive material with high adhesion may be formed.

[0268] 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 and molybdenum that offer both heat resistance and conductivity. It is preferable to use a conductive material, and it is particularly preferable to use tungsten. When forming it simultaneously with other structures, low-resistance metallic materials such as Cu (copper) or Al (aluminium) are used. You can use (Mu), etc.

[0269] An insulator 650 is provided on the conductor 620 and the insulator 630. 0 can be provided using the same material as insulator 320. Also, insulator 650 is It may also function as a flattening film that covers the uneven surface below it.

[0270] By using this structure, in semiconductor devices using transistors having oxide semiconductors This can suppress fluctuations in electrical characteristics and improve reliability. Or, on A transistor having an oxide semiconductor with a high current can be provided. Or, off It is possible to provide a transistor having an oxide semiconductor with a low current. Or, A semiconductor device with reduced power consumption can be provided. Alternatively, a device having an oxide semiconductor can be provided. In semiconductor devices using transistors, miniaturization or high integration can be achieved.

[0271] <Example of transistor structure> The transistor 500 of the semiconductor device shown in this embodiment is not limited to the above structure. No. Below, we will describe some structural examples that can be used in transistor 500.

[0272] <Example of transistor structure 1> An example of the structure of transistor 510A is illustrated using Figures 15A, 15B, and 15C. Figure 15A is a top view of transistor 510A. Figure 15B is the same as Figure 15A but with a dashed line L1 -This is a cross-sectional view of the area indicated by L2. Figure 15C shows the area indicated by the dashed line W1-W2 in Figure 15A. This is a cross-sectional view of the position. Note that in the top view of Figure 15A, some elements have been omitted for clarity. This is illustrated in the diagram.

[0273] Figures 15A, 15B, and 15C show transistor 510A and the interlayer film functioning as an interlayer film. Insulator 511, Insulator 512, Insulator 514, Insulator 516, Insulator 580, Insulator 5 It shows 82 and insulator 584. It is also electrically connected to transistor 510A. , Conductor 546 (Conductor 546a, and Conductor 546) which functions as a contact plug b) shows a conductor 503 that functions as wiring.

[0274] Transistor 510A has a conductor 560 that functions as the first gate electrode (conductor 560 a) and conductor 560b), and conductor 505 (conductor) which functions as a second gate electrode. 505a, and conductor 505b), and insulator 550 which functions as the first gate insulating film And, insulators 521, 522, and 52, which function as a second gate insulating film. 4 and an oxide 530 (oxide 530a, oxide 530a) having a region in which a channel is formed b) and oxide 530c), and a conductor 54 that functions as either a source or a drain. 2a, a conductor 542b that functions as the other of source or drain, and an insulator 574 It has.

[0275] Furthermore, in the transistor 510A shown in Figure 15, oxide 530c, insulator 550, and The conductor 560 is placed in an opening provided in the insulator 580 via the insulator 574. Furthermore, oxide 530c, insulator 550, and conductor 560 are conductor 542a, It is placed between the conductor 542b and the conductor 542b.

[0276] Insulators 511 and 512 function as interlayer films.

[0277] The interlayer films include silicon oxide, silicon oxide nitride, silicon nitride oxide, and aluminum oxide. Hafnium oxide, tantalum oxide, zirconium oxide, lead zirconate titanate (PZT ), strontium titanate (SrTiO3) or (Ba,Sr)TiO3 (BST) Insulators such as these can be used in single or multilayer configurations. Alternatively, these insulators can be, for example, Aluminum oxide, bismuth oxide, germanium oxide, niobium oxide, silicon oxide, acid Titanium oxide, tungsten oxide, yttrium oxide, and zirconium oxide may be added. Alternatively, these insulators may be subjected to nitridation treatment. The above insulators may be subjected to silicon oxide, silicon oxide nitride, and silicon oxide nitride. Recon or silicon nitride may be used in a laminated form.

[0278] For example, insulator 511 allows impurities such as water or hydrogen to enter transistor 510 from the substrate side. It is preferable that it functions as a barrier film to suppress contamination of A. Therefore, an insulator 511 has the function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, and copper atoms. It is preferable to use an insulating material that does not easily allow the above impurities to permeate. Alternatively, oxygen ( For example, it has the function of suppressing the diffusion of at least one of the following: an oxygen atom, an oxygen molecule, etc. (above) It is preferable to use an insulating material (which is less permeable to oxygen). Also, for example, insulator 51 Aluminum oxide or silicon nitride may be used as component 1. With this configuration, hydrogen, Impurities such as water diffuse from the substrate side towards the transistor 510A side rather than from the insulator 511. It can be suppressed.

[0279] For example, it is preferable that the dielectric constant of the insulator 512 is lower than that of the insulator 511. By using a special material as the interlayer film, parasitic capacitance between wiring can be reduced.

[0280] The conductor 503 is formed to be embedded in the insulator 512. The height of the top surface of the conductor and the height of the top surface of the insulator 512 can be made to be approximately the same. While the present invention describes a layered configuration, it is not limited thereto. For example, The conductive body 503 may have a multilayer film structure of two or more layers. It is preferable to use a highly conductive material whose main component is copper or aluminum. stomach.

[0281] In transistor 510A, the conductor 560 is the first gate (also known as the top gate) (u) It may function as an electrode. Also, the conductor 505 is the second gate (bottom gate). It may function as an electrode (also called a toe). In that case, the potential applied to the conductor 505 By changing this independently of the potential applied to the conductor 560, the transient The threshold voltage of the 510A can be controlled. In particular, a negative potential can be applied to the conductor 505. By adding this, the threshold voltage of transistor 510A is made greater than 0V, and the off-current This makes it possible to reduce the amount of conductor 505. Therefore, applying a negative potential to the conductor 505 is preferable. The drain current when the potential applied to the conductor 560 is 0V is smaller than when no potential is applied. It can be done.

[0282] Furthermore, for example, by superimposing the conductor 505 and the conductor 560, the conductor 560 , and when a potential is applied to the conductor 505, the electric field generated from the conductor 560 and the conductor 5 The electric field generated from 05 connects with and covers the channel formation region formed in the oxide 530. It is possible.

[0283] In other words, the electric field of the conductor 560 which functions as the first gate electrode, and the second gate electric field The electric field of the conductor 505, which functions as a pole, electrically isolates the channel formation region. It can be surrounded. That is, similar to transistor 500 described earlier, surround It has a ded channel (S-channel) structure.

[0284] Insulators 514 and 516, like insulator 511 or insulator 512, are interlayer It functions as a film. For example, insulator 514 allows impurities such as water or hydrogen to enter from the substrate side. It is preferable that it functions as a barrier film to suppress contamination of transistor 510A. With this configuration, impurities such as hydrogen and water can enter the transistor 5 from the substrate side rather than from the insulator 514. This can suppress diffusion to the 10A side. Also, for example, insulator 516 is an insulator A dielectric constant lower than 514 is preferable. By using a material with a low dielectric constant as the interlayer film, This can reduce the parasitic capacitance that occurs between lines.

[0285] The conductor 505, which functions as a second gate, is located at the openings of the insulators 514 and 516. A conductor 505a is formed in contact with the inner wall, and a conductor 505b is formed further inside. Here, the height of the upper surfaces of the conductors 505a and 505b and the upper surface of the insulator 516 The height can be made to be about the same. Note that in transistor 510A, the conductor 505a and the conductor Although the present invention describes a configuration in which 505b is stacked, the present invention is not limited thereto. For example, the conductor 505 may be a single layer or a laminated structure of three or more layers.

[0286] Here, the conductor 505a 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., one that does not easily allow the above-mentioned impurities to pass through). Alternatively, inhibit the diffusion of oxygen (e.g., at least one oxygen atom, oxygen molecule, etc.). It is preferable to use a conductive material that has a function (that is impermeable to the above-mentioned oxygen). In the specification, the function of suppressing the diffusion of impurities or oxygen means the above impurities or above The function is to suppress the diffusion of any one or all of the specified oxygen molecules.

[0287] For example, conductor 505a has the function of suppressing oxygen diffusion, so conductor 505b This can suppress the oxidation that causes a decrease in conductivity.

[0288] Furthermore, if the conductor 505 also functions as wiring, the conductor 505b may be tungsten, copper, Alternatively, it is preferable to use a highly conductive material, mainly composed of aluminum. In that case, the conductor 503 does not necessarily have to be provided. Note that the conductor 505b is a single layer. As shown in the illustration, a laminated structure is also possible, for example, titanium or titanium nitride and the above conductive material It may also be a stacked structure.

[0289] Insulators 521, 522, and 524 function as a second gate insulating film. It has.

[0290] Furthermore, it is preferable that the insulator 522 has barrier properties. This prevents impurities such as hydrogen from entering the transistor 510A from its peripheral area. It functions as a layer that prevents contamination.

[0291] 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 (Ba It is preferable to use an insulator containing ,Sr)TiO3(BST) or the like in a single layer or multilayer configuration. As transistors become smaller and more integrated, the gate insulating film becomes thinner, leading to... Problems such as high current may occur. The insulator that functions as a gate insulating film is high- By using k material, the gate potential during transistor operation can be reduced while maintaining the physical film thickness. This becomes possible.

[0292] Furthermore, it is preferable that the insulator 521 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 A laminated insulator 521 with a high dielectric constant can be obtained.

[0293] Note that Figure 15 shows a three-layer stacked structure as the second gate insulating film, but a single layer, or It may be a laminated structure of four or more layers. In that case, it is not limited to a laminated structure made of the same material. Alternatively, it may be a laminated structure made of different materials.

[0294] Oxide 530 having a region that functions as a channel-forming region is oxide 530a and It has an oxide 530b on substance 530a and an oxide 530c on oxide 530b. Because oxide 530a is present below oxide 530b, it is formed below oxide 530a. This can suppress the diffusion of impurities from the structure to oxide 530b. Having oxide 530c on 530b, the structure formed above oxide 530c The diffusion of impurities from the material to oxide 530b can be suppressed. Therefore, an oxide semiconductor, which is a type of metal oxide as described above, can be used.

[0295] Furthermore, the oxide 530c enters the opening provided in the insulator 580 via the insulator 574. It is preferable that it be provided. If the insulator 574 has barrier properties, from the insulator 580 This can suppress the diffusion of impurities into oxide 530.

[0296] The conductor 542 functions as a source electrode on one end and a drain electrode on the other.

[0297] Conductors 542a and 542b are aluminum, titanium, chromium, nickel, and copper. , yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, etc. Metals or alloys with metals as the main component can be used. In particular, tantalum nitride and others Metal nitride films have barrier properties against hydrogen or oxygen, and also have high oxidation resistance, preferable.

[0298] Furthermore, although Figure 15 shows a single-layer structure with conductors 542a and 542b, two layers or more are also shown. The above layered structure is also acceptable. For example, a tantalum nitride film and a tungsten film can be layered. Furthermore, a titanium film and an aluminum film may be laminated. Also, an aluminum film may be placed on a tungsten film. A two-layer structure with stacked aluminum films, or a copper film stacked on a copper-magnesium-aluminum alloy film. Two-layer structure, two-layer structure with copper film laminated on titanium film, two-layer structure with copper film laminated on tungsten film A two-layer structure is also acceptable.

[0299] 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. It has a three-layer structure that forms a molybdenum nitride film, etc. Furthermore, indium oxide, tin oxide or A transparent conductive material containing zinc oxide may also be used.

[0300] Furthermore, a barrier layer may be provided on the conductor 542. The barrier layer is resistant to oxygen or hydrogen. It is preferable to use a material that has barrier properties. With this configuration, the insulator 574 is formed This can suppress the oxidation of the conductor 542 during film formation.

[0301] For example, metal oxides can be used for the barrier layer. In particular, aluminum oxide, acid Insulating films that provide barriers to oxygen and hydrogen, such as hafnium oxide and gallium oxide, are used. This is preferable. Alternatively, silicon nitride formed by the CVD method may be used.

[0302] Having a barrier layer broadens the range of material choices for the conductor 542. For example, Conductor 542 has low oxidation resistance but high conductivity, such as tungsten and aluminum. Any material can be used. Also, for example, a conductive material that is easy to deposit or process can be used. It is possible.

[0303] Insulator 550 functions as the first gate insulating film. Insulator 550 is connected to insulator 580. The provided opening is provided via oxide 530c and insulator 574. preferable.

[0304] As transistors become smaller and more integrated, the gate insulating film becomes thinner, leading to leakage Problems such as current may occur. In that case, the insulator 550 and the second gate insulating film Similarly, a laminated structure may be used. The insulator that functions as the gate insulating film is made of a 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 made into a layered structure.

[0305] The conductor 560, which functions as the first gate electrode, is composed of conductor 560a and conductor 560 Conductor 560b is located on a. Conductor 560a, like conductor 505a, has hydrogen atoms Using a conductive material that has the function of suppressing the diffusion of impurities such as hydrogen molecules, water molecules, and copper atoms. It is preferable that oxygen is present. Alternatively, at least one such oxygen (e.g., an oxygen atom, an oxygen molecule, etc.) It is preferable to use a conductive material that has the function of suppressing the diffusion of )

[0306] Because conductor 560a has the function of suppressing oxygen diffusion, the material selection of conductor 560b This broadens the range of options. In other words, having conductor 560a means that conductor 560b This suppresses oxidation and prevents a decrease in conductivity.

[0307] Examples of conductive materials that have the function of suppressing oxygen diffusion include tantalum and tantalum nitride. It is preferable to use ruthenium or ruthenium oxide. Also, conductor 560 As a, an oxide semiconductor that can be used as oxide 530 can be used. In that case, by depositing the conductor 560b using the sputtering method, the electrical properties of the conductor 560a are By reducing its resistance, it can be made into a conductor. This is called OC (Oxide Conduct). This can be called a tor electrode.

[0308] Conductor 560b is a conductive material whose main components are tungsten, copper, or aluminum. It is preferable to use it. Also, since the conductor 560 functions as wiring, the conductor 560 It is preferable to use a highly conductive material for b. For example, tungsten, copper, or a A conductive material mainly composed of luminium can be used. In addition, the conductor 560b is multiplicative. It can also be in a layered structure, for example, as a laminate of titanium or titanium nitride and the above conductive material. good.

[0309] An insulator 574 is placed between the insulator 580 and the transistor 510A. This refers to an insulating material that has the function of suppressing the diffusion of impurities such as water or hydrogen, and oxygen. It is good to use them. For example, aluminum oxide or hafnium oxide is preferred. It is also, for example, magnesium oxide, gallium oxide, germanium oxide, acid Yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, or tantalum oxide Any metal oxide, silicon nitride, or silicon nitride can be used.

[0310] The presence of the insulator 574 prevents the oxidation of water and other impurities such as hydrogen present in the insulator 580. The diffusion of material 530c to oxide 530b via insulator 550 can be suppressed. It can do so. Furthermore, the excess oxygen present in the insulator 580 suppresses the oxidation of the conductor 560. It is possible.

[0311] Insulators 580, 582, and 584 function as interlayer films.

[0312] Insulator 582, like insulator 514, is designed to prevent impurities such as water or hydrogen from entering from the outside. It is preferable that it functions as a barrier insulating film to suppress contamination of ZISTA 510A.

[0313] Furthermore, insulators 580 and 584, like insulator 516, are more efficient than insulator 582. It is preferable that the dielectric constant is low. By using a material with a low dielectric constant as the interlayer film, the space between the wiring is filled. This can reduce the parasitic capacity.

[0314] Furthermore, transistor 510A is embedded in insulators 580, 582, and 584. It may also be electrically connected to other structures via plugs and wiring such as the embedded conductor 546. stomach.

[0315] Furthermore, the material for the conductor 546 may be a metal material, an alloy material, or a metal, similar to the conductor 505. Using conductive materials such as nitride materials or metal oxide materials in a single layer or in a laminated configuration. This is possible. For example, high-melting-point materials such as tungsten and molybdenum that have both heat resistance and conductivity. It is preferable to use a material. Alternatively, it may be formed from a low-resistance conductive material such as aluminum or copper. It is preferable to do so. Wiring resistance can be reduced by using a low-resistance conductive material.

[0316] For example, conductor 546 is a conductor that has barrier properties against hydrogen and oxygen. By using a laminated structure of tantalum nitride and highly conductive tungsten, the wiring can be It is possible to suppress the diffusion of impurities from the outside while maintaining the conductivity.

[0317] By having the above structure, a transistor with an oxide semiconductor that has a large on-current is used. A semiconductor device can be provided. Alternatively, a device having an oxide semiconductor with a low off-current can be provided. A semiconductor device using a transistor can be provided. Alternatively, variations in electrical characteristics can be suppressed. The aim is to provide a semiconductor device that has stable electrical characteristics and improved reliability. can.

[0318] <Example of transistor structure 2> An example of the structure of transistor 510B is illustrated using Figures 16A, 16B, and 16C. Figure 16A is a top view of transistor 510B. Figure 16B is the same as Figure 16A but with a dashed line L1 -This is a cross-sectional view of the area indicated by L2. Figure 16C shows the area indicated by the dashed line W1-W2 in Figure 16A. This is a cross-sectional view of the position. Note that in the top view of Figure 16A, some elements have been omitted for clarity. This is illustrated in the diagram.

[0319] Transistor 510B is a modified version of transistor 510A. Therefore, the explanation is repeated. To prevent misunderstandings, I will primarily explain the differences between this transistor and the 510A.

[0320] Transistor 510B consists of conductor 542 (conductor 542a and conductor 542b), It has a region in which oxide 530c, insulator 550, and conductor 560 are superimposed. This structure allows for the provision of transistors with high on-current. Furthermore, controllability is also improved. This can provide high-performance transistors.

[0321] The conductor 560, which functions as the first gate electrode, is composed of conductor 560a and conductor 560 Conductor 560b is located on a. Conductor 560a, like conductor 505a, has hydrogen atoms Using a conductive material that has the function of suppressing the diffusion of impurities such as hydrogen molecules, water molecules, and copper atoms. It is preferable that oxygen is present. Alternatively, at least one such oxygen (e.g., an oxygen atom, an oxygen molecule, etc.) It is preferable to use a conductive material that has the function of suppressing the diffusion of )

[0322] Because conductor 560a has the function of suppressing oxygen diffusion, the material selection of conductor 560b This broadens the range of options. In other words, having conductor 560a means that conductor 560b This suppresses oxidation and prevents a decrease in conductivity.

[0323] Also, the top and side surfaces of the conductor 560, the side surfaces of the insulator 550, and the side surfaces of the oxide 530c It is preferable to provide an insulator 574 so as to cover the surface. Note that the insulator 574 is water-resistant. This is achieved by using an insulating material that has the function of suppressing the diffusion of impurities such as hydrogen and oxygen. For example, it is preferable to use aluminum oxide or hafnium oxide. Other examples include magnesium oxide, gallium oxide, germanium oxide, and yttrium oxide. Metal acids such as um, zirconium oxide, lanthanum oxide, neodymium oxide, or tantalum oxide Sulfur oxides, silicon nitride, or silicon nitride can be used.

[0324] By providing the insulator 574, oxidation of the conductor 560 can be suppressed. By having body 574, impurities such as water and hydrogen present in the insulator 580 transition This can suppress the diffusion to ST510B.

[0325] Furthermore, between the conductor 546 and the insulator 580, there is an insulator 576 (insulator) that has barrier properties. 576a and insulator 576b) may be provided. By providing insulator 576, To suppress the reaction of oxygen in the edge material 580 with the conductor 546, thereby preventing oxidation of the conductor 546. It is possible.

[0326] Furthermore, by providing a barrier-type insulator 576, the conductor used in plugs and wiring This broadens the range of material selection. For example, the conductor 546 can have the property of absorbing oxygen. On the other hand, by using highly conductive metal materials, low-power semiconductor devices can be provided. This is possible. Specifically, while tungsten and aluminum have low oxidation resistance, Highly conductive materials can be used. Furthermore, for example, conductive materials that are easy to deposit films on or process can be used. An electric body can be used.

[0327] <Example of transistor structure 3> An example of the structure of transistor 510C is illustrated using Figures 17A, 17B, and 17C. Figure 17A is a top view of transistor 510C. Figure 17B is the same as Figure 17A but with a dashed line L1 -This is a cross-sectional view of the area indicated by L2. Figure 17C shows the area indicated by the dashed line W1-W2 in Figure 17A. This is a cross-sectional view of the position. Note that in the top view of Figure 17A, some elements have been omitted for clarity. This is illustrated in the diagram.

[0328] Transistor 510C is a modified version of transistor 510A. Therefore, the explanation is repeated. To prevent misunderstandings, I will primarily explain the differences between this transistor and the 510A.

[0329] The transistor 510C shown in Figure 17 has a conductor 5 between the conductor 542a and the oxide 530b. 47a is positioned, and conductor 547b is positioned between conductor 542b and oxide 530b. Here, conductor 542a (conductor 542b) is conductor 547a (conductor 547b ) extends beyond the upper surface and the side surface on the conductor 560 side, and the area in contact with the upper surface of the oxide 530b It has a region. Here, the conductor 547 is a conductor that can be used in the conductor 542. It is sufficient if the thickness of the conductor 547 is at least thicker than that of the conductor 542. It's nice.

[0330] The transistor 510C shown in Figure 17 has the above configuration, and therefore the transistor The conductor 542 can be brought closer to the conductor 560 than the sta 510A. Alternatively, The ends of the electric body 542a and the ends of the conductor 542b can be stacked with the conductor 560. This effectively shortens the channel length of the 510C transistor, reducing the on-current and frequency. This allows for improvement of the wavenumber characteristics.

[0331] Furthermore, conductor 547a (conductor 547b) is superimposed on conductor 542a (conductor 542b) It is preferable that it be provided in this manner. With this configuration, the conductor 546a (conductor In etching to form an opening for embedding 546b), conductor 547a (conductor 54 7b) acts as a stopper, preventing oxide 530b from being over-etched. It is possible.

[0332] Furthermore, the transistor 510C shown in Figure 17 is in contact with the insulator 544 and the insulator 545. The arrangement may also be as follows. The insulator 544 may contain impurities such as water or hydrogen, or excess Barrier insulation prevents oxygen from entering transistor 510C from the insulator 580 side. It is preferable that it functions as a film. The insulator 545 is used as the insulator 544. A suitable insulator can be used. For example, aluminum nitride can be used as the insulator 544. Titanium, aluminum nitride, titanium nitride, silicon nitride, or silicon oxide nitride Any nitride insulator may be used.

[0333] Furthermore, the transistor 510C shown in Figure 17 is different from the transistor 510A shown in Figure 15. Alternatively, the conductor 505 may be provided in a single-layer structure. In this case, the patterned conductor 50 An insulating film that will become an insulator 516 is formed on 5, and the upper part of the insulating film is the upper surface of the conductor 505. The material can be removed using methods such as CMP until it is exposed. Here, the upper surface of the conductor 505 is flat It is preferable to improve the conductivity. For example, the average surface roughness (Ra) of the upper surface of the conductor 505 should be 1 The size should be less than or equal to nm, preferably less than or equal to 0.5 nm, and more preferably less than or equal to 0.3 nm. This improves the flatness of the insulating layer formed on the conductor 505, and oxide 530b Furthermore, it is possible to improve the crystallinity of oxide 530c.

[0334] <Example of transistor structure 4> An example of the structure of transistor 510D is illustrated using Figures 18A, 18B, and 18C. Figure 18A is a top view of transistor 510D. Figure 18B is the same as Figure 18A but with a dashed line L1 -This is a cross-sectional view of the area indicated by L2. Figure 18C shows the area indicated by the dashed line W1-W2 in Figure 18A. This is a cross-sectional view of the position. Note that in the top view of Figure 18A, some elements have been omitted for clarity. This is illustrated in the diagram.

[0335] Transistor 510D is a modified version of the above transistor. Therefore, to avoid repetition of the explanation... Therefore, I will mainly explain the differences from the transistors mentioned above.

[0336] In Figures 18A to 18C, the conductor 503 is omitted, and it functions as a second gate. The conductive material 505 also functions as wiring. In addition, an insulator 550 is placed on the oxide 530c. It has a metal oxide 552 on the insulator 550. In addition, it has a conductive material on the metal oxide 552. It has a body 560, and an insulator 570 on the conductor 560. Furthermore, an insulating material is placed on the insulator 570. It has a body 571.

[0337] The metal oxide 552 preferably has the function of suppressing oxygen diffusion. By providing a metal oxide 552 between the conductive material 560 and the conductive material, which suppresses the diffusion of oxygen, The diffusion of oxygen to body 560 is suppressed. In other words, the amount of oxygen supplied to oxide 530 is reduced. It can be suppressed. Furthermore, it can suppress the oxidation of the conductor 560 by oxygen.

[0338] Furthermore, the metal oxide 552 may function as part of the first gate. For example, An oxide semiconductor that can be used as oxide 530 is used as metal oxide 552. This is possible. In that case, by depositing the conductive material 560 using the sputtering method, metal oxidation can be achieved. The electrical resistance of material 552 can be reduced to create a conductive layer. This can be done using OC (Oxide This can be called a conductor electrode.

[0339] Furthermore, metal oxide 552 may function as part of the gate insulating film. Therefore, when silicon oxide or silicon oxide nitride is used for the insulator 550, metal oxide For 552, it is preferable to use a metal oxide, which is a high-k material with a high dielectric constant. By adopting this laminated structure, it is possible to create a laminated structure that is stable against heat and has a high dielectric constant. Yes, it is possible. Therefore, while maintaining the physical film thickness, the gate voltage applied during transistor operation can be controlled. This allows for a reduction in the position. In addition, the equivalent oxide film thickness (E) of the insulating layer that functions as a gate insulating film is also reduced. This makes it possible to thin the OT (Optical Technology) film.

[0340] In transistor 510D, the metal oxide 552 is shown as a single layer, but a stacked structure of two or more layers is also shown. It may also be constructed as follows: for example, a metal oxide that functions as part of the gate electrode and a gate insulating film. A metal oxide that functions as part of the structure may be layered and provided.

[0341] If the metal oxide 552 is present and it functions as a gate electrode, then from the conductor 560 This allows for an improvement in the on-current of transistor 510D without weakening the effect of the electric field. It can be used. Alternatively, if it functions as a gate insulating film, the insulator 550 and the metal oxide 552 Due to the physical thickness, the distance between the conductor 560 and the oxide 530 is maintained, The leakage current between the electrolytic body 560 and the oxide 530 can be suppressed. Therefore, the insulator By providing a laminated structure with 550 and metal oxide 552, the conductor 560 and oxide 5 The physical distance between 30 and the conductor 560, and the electric field strength from the conductor 560 to the oxide 530, It can be easily adjusted as needed.

[0342] Specifically, the metal oxide 552 can be used in the oxide 530 of the oxide semiconductor. By reducing its resistance, it can be used as metal oxide 552. Alternatively, Hafniu Aluminum, gallium, yttrium, zirconium, tungsten, titanium, One of the following, selected from nitrile, nickel, germanium, or magnesium, Metal oxides containing two or more types can be used.

[0343] In particular, the insulating layer contains an oxide of either aluminum or hafnium, or both. Aluminum oxide, hafnium oxide, aluminum and hafnium oxide (Haf It is preferable to use materials such as hafnium aluminate. In particular, hafnium aluminate is It has higher heat resistance than hafnium oxide film. Therefore, in subsequent heat treatment processes, crystals It is preferable because it is less prone to oxidation. Note that metal oxide 552 is not an essential component. The design should be adjusted according to the characteristics of the transistor.

[0344] The insulator 570 has the function of suppressing the permeation of impurities such as water or hydrogen, and oxygen. It is preferable to use insulating materials. For example, aluminum oxide or hafnium oxide can be used. It is preferable that the conductor 560 is acidified by oxygen from above the insulator 570. It can suppress the transformation. Also, water or hydrogen from above the insulator 570 Which impurities are mixed into the oxide 530 via the conductor 560 and the insulator 550? It can be suppressed.

[0345] The insulator 571 functions as a hard mask. By providing the insulator 571, the conductor 56 During the processing of 0, the side surface of the conductor 560 is approximately perpendicular, specifically, the side surface of the conductor 560 and the substrate. The angle formed by the surfaces shall be between 75 degrees and 100 degrees, preferably between 80 degrees and 95 degrees. It is possible.

[0346] Furthermore, the insulator 571 has a function to suppress the permeation of impurities such as water or hydrogen, and oxygen. By using an insulating material, it may also function as a barrier layer. The insulator 570 does not need to be provided.

[0347] Using insulator 571 as a hard mask, insulator 570, conductor 560, metal oxide 5 By selectively removing a portion of 52, the insulator 550, and the oxide 530c, these The sides can be made to roughly coincide, and a portion of the oxide 530b surface can be exposed.

[0348] Furthermore, transistor 510D has a region 531a on a part of the exposed oxide 530b surface. It has region 531a and region 531b. Either region 531a or region 531b is used as the source region. The other side functions as a drain area.

[0349] The formation of regions 531a and 531b can be achieved, for example, by ion implantation or ion doping. Using plasma immersion ion implantation or plasma treatment, exposed oxidative This can be achieved by introducing impurity elements such as phosphorus or boron to the surface of material 530b. In this embodiment and others, "impurity element" refers to an element other than the main component element.

[0350] Furthermore, a metal film is deposited after a portion of the oxide 530b surface is exposed, and then heat treatment is performed. By doing so, the elements contained in the metal film are diffused into the oxide 530b, and region 531a and It is also possible to form region 531b.

[0351] In the region where the impurity element oxide 530b is introduced, the electrical resistivity decreases. Therefore, Regions 531a and 531b are sometimes referred to as the "impurity region" or "low resistance region." .

[0352] By using the insulator 571 and / or the conductor 560 as a mask, region 531a The region 531b can be formed in a self-aligned manner. Regions 531a and / or 531b do not overlap with the conductor 560, thus reducing parasitic capacitance. It can be reduced. Also, the channel formation region and the source drain region (region 531a or No offset region is formed between region 531b). Region 531a and region 531 By forming b in a self-aligned manner, the on-current increases, the threshold This enables features such as reduced voltage and improved operating frequency.

[0353] Furthermore, in order to further reduce the off-current, off-current is controlled between the channel formation region and the source-drain region. A set region may be provided. The offset region is a region with high electrical resistivity, as mentioned above. This is a region where no impurity elements are introduced. The formation of the offset region occurs in insulator 575 This can be achieved by introducing the aforementioned impurity elements after the formation of the insulator 57 5 also functions as a mask, similar to insulator 571. Therefore, oxide 530b is an insulator. By not introducing impurity elements into the region overlapping with 575, the electrical resistivity of that region remains high. It is possible.

[0354] Furthermore, transistor 510D consists of insulator 570, conductor 560, metal oxide 552, and insulation. The body 550 and the oxide 530c have an insulator 575 on their sides. The insulator 575 is 100% induced It is preferable to use an insulator with a low electrical charge. For example, silicon oxide, silicon oxide nitride, and nitrile Silicon oxide, silicon nitride, silicon oxide with added fluorine, silicon oxide with added carbon Silicon oxide with added carbon and nitrogen, porous silicon oxide, or resin It is preferable that it be a fat or similar substance. In particular, silicon oxide, silicon oxide nitride, silicon nitride If silicon oxide having voids is used as the insulator 575, in a later process, It is preferable because it allows for the easy formation of an excess oxygen region. Also, silicon oxide and silicon oxidnitride Con is preferable because it is thermally stable. In addition, the insulator 575 has the function of diffusing oxygen. It is preferable to have it.

[0355] Furthermore, transistor 510D has an insulator 575 and an insulator 574 on an oxide 530. The insulator 574 is preferably deposited using the sputtering method. By using this method, it is possible to form an insulating film with few impurities such as water or hydrogen. For example, aluminum oxide can be used as the insulator 574.

[0356] Note that oxide films produced by sputtering may extract hydrogen from the structure to which the film is deposited. Therefore, insulator 574 absorbs hydrogen and water from oxide 530 and insulator 575. This makes it possible to reduce the hydrogen concentration of oxide 530 and insulator 575.

[0357] <Example of transistor structure 5> Figures 19A to 19C illustrate an example of the structure of transistor 510E. Figure 19A shows This is a top view of the Rangista 510E. Figure 19B is shown in Figure 19A by the dashed line L1-L2. This is a cross-sectional view of the area. Figure 19C is a cross-sectional view of the area shown by the dashed line W1-W2 in Figure 19A. Yes. Note that in the top view of Figure 19A, some elements have been omitted for clarity. ru.

[0358] Transistor 510E is a modified version of the above transistor. Therefore, to avoid repetition of the explanation... Therefore, I will mainly explain the differences from the transistors mentioned above.

[0359] In Figures 19A to 19C, without providing the conductor 542, the exposed surface of the oxide 530b is shown. The part has region 531a and region 531b. Either region 531a or region 531b One region functions as the source region, and the other functions as the drain region. Also, oxide 530b And, between the insulator 574, there is an insulator 573.

[0360] As shown in Figure 19, region 531 (regions 531a and 531b) is oxide 530b. The following elements are added to the region. Region 531 can be used, for example, by using a dummy gate. It can be formed with.

[0361] Specifically, a dummy gate is provided on oxide 530b, and the dummy gate is used as a mask. It is preferable to use and add an element that reduces the resistance of the above oxide 530b. In other words, oxide 530 However, when the element is added to a region that does not overlap with the dummy gate, region 531 is formed. The method for adding the element involves mass-separating the ionized raw material gas and then adding it. Ion implantation method, ion doping method in which ionized source gas is added without mass separation. Plasma immersion ion implantation methods can be used.

[0362] In addition, typical elements that reduce the resistance of oxide 530 include boron and phosphorus. It can also be achieved using hydrogen, carbon, nitrogen, fluorine, sulfur, chlorine, titanium, noble gases, etc. Good. Typical examples of noble gases include helium, neon, argon, krypton, and xenon. These include [examples of elements]. The concentration of the element in question can be measured using SIMS or similar methods.

[0363] In particular, boron and phosphorus can be produced using equipment such as that used in low-temperature polysilicon manufacturing lines. This is preferable because it allows for the reuse of existing equipment, thereby reducing capital investment. can.

[0364] Next, oxide 530b and an insulating film which will become an insulator 573 are placed on the dummy gate, An insulating film that will become an insulator 574 may be formed. An insulating film that will become an insulator 573, and an insulator By stacking insulating films that make up region 574, the region 531, the oxide 530c and the insulating film are formed. A region can be provided where body 550 and the other body overlap.

[0365] Specifically, an insulating film that will become an insulating film 574 is provided on an insulating film that will become an insulating film 580, and then insulation By performing CMP treatment on the insulating film that will become the insulating material 580, a portion of the insulating film that will become the insulating material 580 is removed. Remove the dummy gate and expose it. Next, when removing the dummy gate, the dummy gate and It is also advisable to remove a portion of the insulator 573 that is in contact with it. Therefore, the opening provided in the insulator 580 On the side surface, insulators 574 and 573 are exposed, and on the bottom surface of the opening, oxidation A portion of the region 531 provided in object 530b is exposed. Next, oxide 530 is applied to the opening. The oxide film that becomes c, the insulating film that becomes the insulator 550, and the conductive film that becomes the conductor 560 are formed in order. After film formation, the oxide 530c is formed by CMP treatment or other processes until the insulator 580 is exposed. By removing a portion of the insulating film that forms the insulating film 550 and the conductive film that forms the conductor 560, Thus, the transistor shown in Figure 19 can be formed.

[0366] Note that insulators 573 and 574 are not essential components. The design should be adjusted according to the specific requirements.

[0367] The transistor shown in Figure 19 can be repurposed from existing equipment, and furthermore, the conductor 542 By eliminating the need for it, costs can be reduced.

[0368] <Example of transistor structure 6> Figures 20A to 20C illustrate an example of the structure of transistor 510F. Figure 20A shows This is a top view of the Rangista 510F. Figure 20B is shown in Figure 20A by the dashed line L1-L2. This is a cross-sectional view of the area. Figure 20C is a cross-sectional view of the area shown by the dashed line W1-W2 in Figure 20A. Yes. Note that in the top view of Figure 20A, some elements have been omitted for clarity. ru.

[0369] Transistor 510F is a modified version of transistor 510A. Therefore, the explanation is repeated. To prevent this, we will mainly explain the differences from the transistors mentioned above.

[0370] In transistor 510A, a portion of the insulator 574 is located within an opening in the insulator 580. It is provided and is provided so as to cover the side surface of the conductor 560. On the other hand, transistor 51 At 0F, an opening is formed by removing parts of the insulators 580 and 574.

[0371] Furthermore, between the conductor 546 and the insulator 580, there is an insulator 576 (insulator) that has barrier properties. 576a and insulator 576b) may be provided. By providing insulator 576, To suppress the reaction of oxygen in the edge material 580 with the conductor 546, thereby preventing oxidation of the conductor 546. It is possible.

[0372] Note that when using an oxide semiconductor as oxide 530, the atomic ratio of each metal atom will differ. It is preferable to have a laminated structure of multiple oxide layers. Specifically, the oxide 530a used In a metal oxide, the atomic ratio of element M in the constituent elements is the metal used in oxide 530b. In oxides, it is preferable that the atomic ratio of element M in the constituent elements is greater than that of the oxide. In the metal oxide used in material 530a, the atomic ratio of element M to In is such that It is preferable that the atomic ratio of element M to In in the metal oxide used for 0b is greater than that of In. Furthermore, in the metal oxide used in oxide 530b, the number of In atoms relative to element M The ratio is greater than the atomic ratio of In to element M in the metal oxide used in oxide 530a. Larger is preferable. Also, oxide 530c is oxide 530a or oxide 530b Metal oxides that can be used for this purpose can be used.

[0373] Oxides 530a, 530b, and 530c are preferably crystalline. In particular, it is preferable to use CAAC-OS. These oxides have few impurities or defects (such as oxygen deficiencies), are highly crystalline, and have a dense structure. Therefore, the oxygen is drawn from oxide 530b by the source electrode or drain electrode. This suppresses the removal of oxygen from oxide 530b. As a result, even after heat treatment, oxygen can be removed from oxide 530b. Because the pull-out of the transistor can be reduced, the 510F transistor has a high manufacturing process. It is stable with respect to temperature (the so-called thermal budget).

[0374] Note that either or both of oxides 530a and 530c may be omitted. 530 may be a single layer of oxide 530b. Oxide 530 may be oxide 530a, oxide When laminating 530b and oxide 530c, oxide 530a and oxide 53 The energy at the lower end of the conduction band for 0c is higher than the energy at the lower end of the conduction band for oxide 530b. It is preferable that the electron parent of oxide 530a and oxide 530c It is preferable that the summing force is smaller than the electron affinity of oxide 530b. In this case, oxide 53 For 0c, it is preferable to use a metal oxide that can be used in oxide 530a. Specifically Specifically, in metal oxides used in oxide 530c, the atomic ratio of element M in the constituent elements is , greater than the atomic ratio of element M in the constituent elements of the metal oxide used in oxide 530b It is preferable that the metal oxide used in oxide 530c contains the element for In. The atomic ratio of element M is the ratio of element M to In in the metal oxide used in oxide 530b. It is preferable that it is greater than the atomic ratio. Also, in the metal oxide used in oxide 530b The atomic ratio of In to element M is the element in the metal oxide used in oxide 530c. It is preferable that the atomic ratio of In to M is greater than that of M.

[0375] Here, at the joint of oxide 530a, oxide 530b, and oxide 530c, The energy levels at the lower end of the guide band change smoothly. In other words, oxide 530a, oxide The energy levels at the lower end of the conduction band at the junction of 530b and oxide 530c are continuous. It can also be said that it undergoes a gradual change or continuous bonding. In order to do this, oxide 5 At the interface between 30a and oxide 530b, and at the interface between oxide 530b and oxide 530c It is desirable to lower the defect level density of the mixed layer that is formed.

[0376] Specifically, oxide 530a and oxide 530b, and oxide 530b and oxide 530c, By having a common element other than the primary element (as the main component), a mixed layer with a low defect level density is formed. It is possible. For example, if oxide 530b is In-Ga-Zn oxide, then oxide 5 As 30a and oxide 530c, In-Ga-Zn oxide, Ga-Zn oxide, oxide Gallium or the like may be used. Alternatively, oxide 530c may be used in a layered structure. For example, I A laminated structure of n-Ga-Zn oxide and Ga-Zn oxide on the In-Ga-Zn oxide. A compound, or an In-Ga-Zn oxide and gallium oxide on the In-Ga-Zn oxide A layered structure can be used. In other words, an In-Ga-Zn oxide and an In-containing A laminated structure with an oxide that does not contain the oxide may be used as oxide 530c.

[0377] Specifically, as oxide 530a, In:Ga:Zn = 1:3:4 [atomic ratio], For this, a metal oxide with an atomic ratio of 1:1:0.5 should be used. Also, as oxide 530b For metals with an atomic ratio of In:Ga:Zn = 4:2:3 or 3:1:2. You can use an oxide. Also, as oxide 530c, In:Ga:Zn=1:3:4[ [Atomic ratio], In:Ga:Zn=4:2:3 [Atomic ratio], Ga:Zn=2:1 [Atomic ratio A metal oxide with a ratio of [ratio] or Ga:Zn = 2:5 [atomic ratio] can be used. A specific example of a laminated structure for material 530c is In:Ga:Zn=4:2:3[original [atomic ratio] and layered structure of Ga:Zn=2:1 [atomic ratio], In:Ga:Zn=4:2 :3 [atomic ratio] and a layered structure of Ga:Zn=2:5 [atomic ratio], In:Ga:Zn Examples include a 4:2:3 [atomic ratio] and a layered structure with gallium oxide.

[0378] In this case, the main carrier pathway is oxide 530b. Oxide 530a, oxide 53 By configuring 0c as described above, the interface between oxide 530a and oxide 530b, and oxidation The defect level density at the interface between material 530b and oxide 530c can be reduced. Therefore, the influence of interfacial scattering on carrier conduction is reduced, and the transistor 510F is high This allows for obtaining ion current and high frequency characteristics. When constructed, the defect level density at the interface between the oxide 530b and oxide 530c is as described above. In addition to the effect of lowering the noise level, the constituent elements of oxide 530c diffuse towards the insulator 550. It is expected that this will be suppressed. More specifically, the oxide 530c is made into a layered structure, and the layered In order to position an In-free oxide above the structure, In can diffuse towards the insulator 550 side. This can be suppressed. The insulator 550 functions as a gate insulator, so In expands. If dispersed, it will result in transistor performance defects. Therefore, oxide 530c is used in a layered structure. This makes it possible to provide highly reliable semiconductor devices.

[0379] For oxide 530, it is preferable to use a metal oxide that functions as an oxide semiconductor. For example, For example, the metal oxide that forms the channel-forming region of oxide 530 has a band gap of 2e It is preferable to use a band of V or higher, preferably 2.5 eV or higher. By using metal oxides with a large gap, the off-current of the transistor can be reduced. Yes, it is possible. By using such transistors, low-power semiconductor devices can be provided. .

[0380] <Example of transistor structure 7> The structure of transistor 510G is explained using Figures 21A and 21B. The 10G is a modified version of the 500 transistor. Therefore, to avoid repetition of the explanation, mainly The differences from the above transistor will be explained. Note that the configuration shown in Figures 21A and 21B is This also applies to other transistors in the semiconductor device of one embodiment of the present invention, such as transistor 300. It can be used.

[0381] Figure 21A is a cross-sectional view of transistor 510G in the channel length direction, and Figure 21B is a cross-sectional view of transistor 510G. This is a cross-sectional view of the transistor 510G in the channel width direction. The transistors shown in Figures 21A and 21B... As shown in Figures 14A and 14B, the sta 510G has insulators 402 and 404. This is different from transistor 500. Also, an insulator 551 is provided in contact with the side surface of the conductor 540a. The point where the insulator 551 is provided in contact with the side surface of the conductor 540b is shown in Figures 14A and 1. It differs from transistor 500 shown in 4B. Furthermore, it does not have an insulator 520, as shown in Figure 14. A is different from transistor 500 shown in Figure 14B.

[0382] The transistor 510G shown in Figures 21A and 21B has an insulator 402 provided on an insulator 512. It can be kicked. In addition, an insulator 404 is provided on the insulator 574 and on the insulator 402.

[0383] In the transistor 510G shown in Figures 21A and 21B, insulator 514, insulator 516, Edge 522, insulator 524, insulator 544, insulator 580, and insulator 574 are patani The structure is such that the insulator 404 covers these layers. This includes the top surface of insulator 574, the side surface of insulator 574, the side surface of insulator 580, and the side of insulator 544. Surface, side of insulator 524, side of insulator 522, side of insulator 516, side of insulator 514 The surface and the upper surface of the insulator 402 are in contact with each other. As a result, the oxide 530 etc. are in contact with the insulator 40 It is isolated from the outside by 4 and the insulator 402.

[0384] Insulators 402 and 404 contain hydrogen (e.g., hydrogen atoms, hydrogen molecules, etc.) It is preferable that one) or has a high function of suppressing the diffusion of water molecules. For example, insulator 402 and As the insulator 404, a material with high hydrogen barrier properties is silicon nitride or silicon nitride oxide. It is preferable to use a cone. This suppresses the diffusion of hydrogen and other substances into oxide 530. This allows us to suppress the degradation of the characteristics of transistor 510G. Therefore, the reliability of one embodiment of the present invention can be improved.

[0385] Insulator 551 is an insulator, an insulator 404, an insulator 574, an insulator 580, and an insulator It is provided in contact with body 544. The insulator 551 has a function to suppress the diffusion of hydrogen or water molecules. It is preferable to have such a material. For example, the insulator 551 is a material with high hydrogen barrier properties. It is preferable to use an insulator such as silicon nitride, aluminum oxide, or silicon nitride oxide. It is indeed. In particular, silicon nitride is a material with high hydrogen barrier properties, so as an insulator 551 It is preferable to use it. By using a material with high hydrogen barrier properties as the insulator 551, Impurities such as water or hydrogen enter through the insulator 580 and conductors 540a and 540b. This can suppress diffusion into oxide 530. Also, the insulator 580 contains This can suppress the absorption of oxygen by conductors 540a and 540b. As a result, the reliability of a semiconductor device according to one embodiment of the present invention can be improved.

[0386] Figure 22 shows the configuration of transistors 500 and 300 as shown in Figures 21A and 21B. This is a cross-sectional view showing an example of the configuration of a semiconductor device when it is made as is. On the side surface of the conductor 546 An insulator 551 is provided.

[0387] Figures 23A and 23B are modified versions of the transistor shown in Figures 21A and 21B. Figure A is a cross-sectional view of the transistor in the direction of the channel length, and Figure 23B is the channel of the transistor. This is a cross-sectional view in the width direction. The transistors shown in Figures 23A and 23B are made of oxide 530c, which is acidic. As shown in Figures 21A and 21B, it has a two-layer structure consisting of oxide 530c1 and oxide 530c2. It is different from a transistor.

[0388] Oxide 530c1 is on the top surface of insulator 524, the side surface of oxide 530a, and the top surface of oxide 530b. Surface and side, side of conductor 542a and conductor 542b, side of insulator 544, and insulation The oxide 530c2 is in contact with the side surface of body 580. The oxide 530c2 is in contact with the insulator 550.

[0389] For example, In-Zn oxide can be used as oxide 530c1. When the oxide 530c has a single-layer structure, the substance 530c2 is used for the oxide 530c. Materials similar to those that can be used can be used. For example, as oxide 530c2, In:Ga:Zn = 1:3:4 [atomic ratio], Ga:Zn = 2:1 [atomic ratio], or Metal oxides with a Ga:Zn ratio of 2:5 [atomic ratio] can be used.

[0390] By making oxide 530c a two-layer structure of oxide 530c1 and oxide 530c2, This allows for a higher on-current of the transistor compared to a single-layer structure of oxide 530c. Therefore, the transistor can be, for example, a power MOS transistor. Furthermore, the oxide 530c present in the transistors shown in Figures 14A and 14B is also oxide 530 A two-layer structure consisting of c1 and oxide 530c2 can be achieved.

[0391] The transistors shown in Figures 23A and 23B are, for example, transistor 500, transistor It can be applied to 300, or both.

[0392] This embodiment may be implemented in appropriate combination with other embodiments described herein. It is possible.

[0393] (Embodiment 4) In this embodiment, the gold that can be used in the OS transistor described in the above embodiment is The composition of the group oxides will be explained.

[0394] <Composition of metal oxides> In this specification, CAAC (c-axis aligned crystal), and It may also be written as CAC (Cloud-Aligned Composite). Note that CAAC represents an example of a crystal structure, and CAC represents an example of a function or material composition. .

[0395] CAC-OS or CAC-metal oxide is a material that has conductive properties in some parts. In addition, a portion of the material has insulating properties, while the material as a whole has semiconductor properties. Furthermore, CAC-OS or CAC-metal oxide is used in the transistor channels. When used in a region where a hole is formed, the conductive function is to allow electrons (or holes) that act as carriers to flow. The function of insulation is the function of preventing the flow of electrons, which act as carriers. The function of conductivity is... By having the insulating function and the other function work complementaryly, a switching function is achieved. The function to switch CAC-OS or CAC-metal oxide on / off is added to the CAC-OS or CAC-metal oxide. It is possible. In CAC-OS or CAC-metal oxide, By separating these functions, it is possible to maximize the performance of both.

[0396] Furthermore, CAC-OS or CAC-metal oxide has conductive and insulating properties. It has regions. The conductive region has the conductive function described above, and the insulating region has the insulating function described above. It has the function of [this]. Furthermore, within the material, the conductive region and the insulating region are at the nanoparticle level. In some cases, they are separated by a rib. Also, conductive regions and insulating regions are located within the material. They may be unevenly distributed. Furthermore, the conductive regions appear blurred around the edges and connected in a cloud-like pattern. There are cases where this occurs.

[0397] Furthermore, in CAC-OS or CAC-metal oxide, the conductive region and the insulating region The marginal region is defined as being between 0.5 nm and 10 nm, preferably between 0.5 nm and 3 nm. These particles may be dispersed in the material at the following sizes.

[0398] Furthermore, CAC-OS or CAC-metal oxide has different band gaps. It is composed of the following components. For example, CAC-OS or CAC-metal oxi de consists of a component with a wide gap due to the insulating region and a component with a wide gap due to the conductive region. It consists of a component having a low gap. In this configuration, when the carrier is flowing... In components with a narrow gap, the carrier mainly flows. A component having a wide gap acts complementaryly with a component having a narrow gap. In conjunction with the components, carriers also flow to components with a wide gap. Therefore, the above C AC-OS or CAC-metal oxide is applied to the channel formation region of the transistor. When used, a high current driving force is required in the transistor's ON state, i.e., a large ON current. Furthermore, a high field-effect mobility can be obtained.

[0399] In other words, CAC-OS or CAC-metal oxide is a matrix composite material. (matrix composite), or metal matrix composite (metal It can also be called a matrix composite.

[0400] <Structure of metal oxides> Oxide semiconductors are divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. As a non-single-crystal oxide semiconductor, for example, CAAC-OS (c-axis ali gned crystalline oxide semiconductor), polycrystalline crystalline oxide semiconductor, nc-OS (nanocrystalline oxide semiconductor) conductor), pseudo-amorphous oxide semiconductor (a-like OS: amorphous (us-like oxide semiconductor) and amorphous oxide semiconductor These are some examples.

[0401] For the oxide semiconductor used in transistors, it is preferable to use a highly crystalline thin film. It seems that using this thin film can improve the stability or reliability of transistors. Yes, it is possible. The thin film can be, for example, a thin film of a single-crystal oxide semiconductor or a thin film of a polycrystalline oxide semiconductor. Thin films are an example. However, thin films of single-crystal oxide semiconductors or polycrystalline oxide semiconductors are examples. Forming such a thin film on a substrate requires a high-temperature or laser heating process. This increases manufacturing costs and also reduces throughput.

[0402] CAAC-OS has c-axis orientation and multiple nanocrystals are linked in the ab-plane direction. Furthermore, it has a distorted crystal structure. Note that distortion refers to the region where multiple nanocrystals are connected. Within the region, between a region with aligned lattice arrangements and another region with aligned lattice arrangements, This refers to the part where the direction has changed.

[0403] Nanocrystals are based on a hexagonal structure, but they are not necessarily regular hexagons; they can also be non-regular hexagonal. Yes, it exists. Furthermore, the distortion may have lattice arrangements such as pentagons and heptagons. Furthermore, in CAAC-OS, even near strain, clear grain boundaries (grain bounds) are present. It is not possible to confirm the dally (also called dally). In other words, due to the distortion of the lattice arrangement, the crystal grain It can be seen that the formation of the boundary is suppressed. This is because CAAC-OS is in the ab-plane direction. The oxygen atoms are not densely arranged, and the substitution of metal elements reduces the bond distance between atoms. This is thought to be because the distortion can be tolerated through changes and other processes.

[0404] Furthermore, CAAC-OS consists of a layer containing indium and oxygen (hereinafter referred to as the In layer), and elements A layered crystalline structure in which layers containing M, zinc, and oxygen (hereinafter referred to as (M,Zn) layers) are stacked. It tends to have a layered structure (also called a structure). Note that indium and element M are relative to each other. It is interchangeable, and if element M in the (M,Zn) layer is replaced with indium, then (In,M,Zn It can also be represented as a layer. Furthermore, if the indium in the In layer is replaced by element M, (In, It can also be represented as layer M.

[0405] CAAC-OS is a highly crystalline oxide semiconductor. On the other hand, CAAC-OS has a clear bond. Since grain boundaries cannot be identified, a decrease in electron mobility caused by grain boundaries does not occur. It can be said that the crystallinity of oxide semiconductors is reduced due to the inclusion of impurities and the generation of defects. Because it may cause problems, CAAC-OS is an oxide with few impurities and defects (such as oxygen deficiencies). It can also be called a semiconductor. Therefore, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat-resistant and highly reliable. CAAC-OS is designed to withstand high temperatures (or thermal budgets) in the manufacturing process. It is also stable. Therefore, when using CAAC-OS in OS transistors, the manufacturing process This will allow for greater flexibility.

[0406] 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. Furthermore, nc-OS has different nanometers. No regularity in crystal orientation is observed between crystals. Therefore, no orientation is observed throughout the entire film. Therefore, depending on the analysis method, nc-OS can be classified as a-like OS or amorphous oxide semiconductor. It can sometimes be difficult to distinguish between them.

[0407] 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.

[0408] 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 nc -OS and CAAC-OS may have two or more types.

[0409] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0410] 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.

[0411] It is preferable to use an oxide semiconductor with a low carrier density for the transistor. When lowering the carrier density of the conductive film, the impurity concentration in the oxide semiconductor film is reduced. Therefore, the defect level density should be lowered. In this specification, the impurity concentration is low and the defect level Low density is referred to as high-purity intrinsic or substantially high-purity intrinsic.

[0412] 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 decrease. The carrier density of the oxide semiconductor can be within the range described in Embodiment 3. .

[0413] 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.

[0414] 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.

[0415] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0416] In oxide semiconductors, if silicon or carbon, which are among the Group 14 elements, are present, the oxide Defect levels are formed in semiconductors. Therefore, silicon and carbon in oxide semiconductors. The concentration of silicon and carbon near the interface with the oxide semiconductor (by secondary ion mass spectrometry) SIMS (Secondary Ion Mass Spectrometry) The resulting concentration is 2 × 10 18 atoms / cm 3 The following is preferably 2 × 10 17 at oms / cm 3 The following applies:

[0417] Furthermore, if alkali metals or alkaline earth metals are present in the oxide semiconductor, defect levels are formed. This can result in the generation of carriers. Therefore, alkali metals or alkaline earth metals Transistors using oxide semiconductors containing this material tend to exhibit normally-on characteristics. Therefore, reducing the concentration of alkali metals or alkaline earth metals in oxide semiconductors is possible. Preferably. Specifically, alkali metals or a in oxide semiconductor obtained by SIMS The concentration of rutile earth metals is 1 × 10⁻⁶ 18 atoms / cm 3 The following is preferably 2 × 10 1 6 atoms / cm 3 Do the following:

[0418] Furthermore, in oxide semiconductors, when nitrogen is present, electrons, which are carriers, are generated. The density increases, making it easier to convert to n-type. As a result, nitrogen-containing oxide semiconductors become channeled. The transistor used in the formation region tends to exhibit normally-on characteristics. Therefore, the oxide semiconductor In conductors, it is preferable to reduce nitrogen content as much as possible. For example, in oxide semiconductors. The nitrogen concentration inside is 5 × 10⁻⁶ in SIMS. 19 atoms / cm 3 Less than, preferably 5 x 10 18 atoms / cm 3 More preferably 1 × 10 18 atoms / cm 3 More preferably 5 × 10 17 atoms / cm 3 The following applies:

[0419] 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. Therefore, 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 Less than.

[0420] Using oxide semiconductors with sufficiently reduced impurities in the channel formation region of transistors. This allows for the provision of stable electrical characteristics.

[0421] The discovery of CAAC and nc structures led to the development of oxide semiconductors having CAAC or nc structures. Improvement of the electrical characteristics and reliability of transistors using a body, and reduction of manufacturing costs. It contributes to improved performance and throughput. Furthermore, the transistor has low leakage current. Research is underway to apply this characteristic of the transistor to semiconductor devices.

[0422] This embodiment may be implemented in appropriate combination with other embodiments described herein. It is possible. [Explanation of Symbols]

[0423] C11: Capacitive element, C12: Capacitive element, C21: Capacitive element, C22: Capacitive element, C41: Capacitive element, C42: Capacitive element, C43: Capacitive element, C51: Capacitive element, C52: Capacitive element C53: Capacitive element, N11: Node, N21: Node, N41: Node, N51: No D, SI1: signal, SI1_IN: input terminal, SI1B: signal, SI1B_IN: input terminal Child, SI2: signal, SI2_IN: input terminal, SI2B: signal, SI2B_IN: input terminal Child, SO1: signal, SO1_OUT: output terminal, SO1B: signal, SO2: signal, SO2 _OUT: Output terminal, SO2B: Signal, 10: Semiconductor device, 10_1: Semiconductor device, 10 _2: Semiconductor device, 11: Transistor, 12: Transistor, 13: Transistor, 1 4: Transistor, 20: Semiconductor device, 21: Transistor, 22: Transistor, 23 : Transistor, 30: Semiconductor device, 31: Transistor, 32: Transistor, 40: Semiconductor device, 41: transistor, 42: transistor, 43: transistor, 44: Ranjista, 45: Transistor, 46: Transistor, 47: Transistor, 50: Semiconductor Conductor device, 51: transistor, 52: transistor, 53: transistor, 54: tra 55: transistor, 56: transistor, 57: transistor, 60: semiconductor Body device, 70: Semiconductor device, 300: Transistor, 311: Substrate, 313: Semiconductor area , 314a: low resistance region, 314b: low resistance region, 315: insulator, 316: conductor, 3 20: Insulator, 322: Insulator, 324: Insulator, 326: Insulator, 328: Conductor, 3 30: Conductor, 350: Insulator, 352: Insulator, 354: Insulator, 356: Conductor, 3 60: Insulator, 362: Insulator, 364: Insulator, 366: Conductor, 370: Insulator, 3 72: Insulator, 374: Insulator, 376: Conductor, 380: Insulator, 382: Insulator, 3 84: Insulator, 386: Conductor, 402: Insulator, 404: Insulator, 500: Transistor T, 503: Conductor, 503a: Conductor, 503b: Conductor, 505: Conductor, 505a : Conductor, 505b: Conductor, 510: Insulator, 510A: Transistor, 510B: Transistor Ranjista, 510C: Transistor, 510D: Transistor, 510E: Transistor T, 510F: Transistor, 510G: Transistor, 511: Insulator, 512: Insulator Body, 514: Insulator, 516: Insulator, 518: Conductor, 520: Insulator, 521: Insulator Body, 522: Insulator, 524: Insulator, 530: Oxide, 530a: Oxide, 530b: Oxide, 530c: Oxide, 530c1: Oxide, 530c2: Oxide, 531: Region, 531a: area, 531b: area, 540a: conductor, 540b: conductor, 542: conductor body, 542a: conductor, 542b: conductor, 543: region, 543a: region, 543b: Region, 544: insulator, 545: insulator, 546: conductor, 546a: conductor, 546b : Conductor, 547: Conductor, 547a: Conductor, 547b: Conductor, 548: Conductor, 5 50: Insulator, 551: Insulator, 552: Metal oxide, 560: Conductor, 560a: Conductor Body, 560b: Conductor, 570: Insulator, 571: Insulator, 573: Insulator, 574: Insulator Edge body, 575: insulator, 576: insulator, 576a: insulator, 576b: insulator, 580 :Insulator, 581:Insulator, 582:Insulator, 584:Insulator, 586:Insulator, 600 : Capacitive element, 610: Conductor, 612: Conductor, 620: Conductor, 630: Insulator, 65 0: Insulator

Claims

[Claim 1] First to fourth transistors, First and second capacitance elements, First and second wiring, First and second input terminals, It has an output terminal, Either the source or drain of the fourth transistor is electrically connected to the first wiring, The source or drain of the fourth transistor is electrically connected to one of the source or drain of the second transistor, one terminal of the second capacitive element, and the gate of the third transistor. The source or drain of the second transistor, the other of which is electrically connected to the second wiring, The gate of the fourth transistor is electrically connected to the first input terminal, one terminal of the first capacitive element, and the gate of the first transistor. The gate of the second transistor is electrically connected to the second input terminal. Either the source or the drain of the first transistor is electrically connected to the first wiring, The source or drain of the first transistor is electrically connected to the other terminal of the first capacitance element, the other terminal of the second capacitance element, the source or drain of the third transistor, and the output terminal. A semiconductor device in which the source or drain of the third transistor, the other of which is electrically connected to the second wiring.

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