Semiconductor equipment

Abstract

To provide a semiconductor device with a novel configuration. [Solution] The semiconductor device has either a source or a drain for reading data. A first transistor electrically connected to the wiring, and either the source or the drain of the first transistor It is electrically connected to the gate of the inverter, and the other side of the source or drain writes data. A second transistor is electrically connected to the second wiring, and one of its sources or drains is Electrically connected to the gate of the first transistor, with the source or drain (the other) corresponding to the data. It has a third transistor electrically connected to a capacitor for holding the charge, The third transistor has a metal oxide in the channel formation region.

Description

Technical Field

[0001] This specification describes a semiconductor device, its operation method, and the like.

[0002] In this specification, a semiconductor device is a device that utilizes semiconductor characteristics, and includes a circuit containing semiconductor elements ( transistors, diodes, photodiodes, etc.), a device having the same circuit, and the like. It also refers to all devices that can function by utilizing semiconductor characteristics. For example, an integrated circuit , a chip equipped with an integrated circuit, or an electronic component in which a chip is housed in a package is an example of a semiconductor device. In addition, a memory device, a display device, a light-emitting device, a lighting device, and an electronic device, etc., are themselves semiconductor devices and may have semiconductor devices.

Background Art

[0003] Metal oxides have been attracting attention as semiconductors applicable to transistors. Indium-gallium-zinc oxide, called "IGZO", "Igzo", etc., is a typical example of a multi-component metal oxide. In research on IGZO, a CAAC (c-axis aligned crystalline) structure and an nc (nanocrystalline) structure, which are neither single crystal nor amorphous, have been found (for example, Non-Patent Document 1). axis aligned crystalline) structure, and nc (nanocr ystalline) structure have been found (for example, Non-Patent Document 1).

[0004] A transistor having a metal oxide semiconductor in a channel formation region (hereinafter sometimes referred to as "oxide semiconductor transistor" [[ID=4o]]or "OS transistor".) has been reported to have an extremely small off-current (for example, Non-Patent Documents 1 and 2). Various semiconductor devices using OS transistors have been fabricated (for example, Non-Patent Documents 3 and 4). OS transistors have been fabricated (for example, Non-Patent Documents 3 and 4). The manufacturing process can be incorporated into a CMOS process with conventional Si transistors. The OS transistor can be stacked on the Si transistor (for example, Non-Patent Document 4).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Summary of the Invention

[0006] The object of one embodiment of the present invention is a semiconductor device that functions as a memory device utilizing an extremely small off-current. In this regard, the objective is to provide a semiconductor device with excellent reliability, such as the ability to retain data for extended periods, and The objective is to provide a semiconductor device that excels in reducing power consumption.

[0007] The description of multiple problems does not preclude the existence of each other. One embodiment of the present invention is, for example, It is not necessary to solve all the problems listed. Furthermore, if there are other problems not listed, this specification may not address them. Therefore, it becomes clear that such problems can also be addressed by one embodiment of the present invention. [Means for solving the problem]

[0008] One aspect of the present invention is that either the source or the drain is connected to a first wiring for reading data. An electrically connected first transistor, and one of its source or drain is the first transistor The gate of the zistor is electrically connected, and the other of the source or drain writes the data. A second transistor electrically connected to the second wiring for, and either the source or the drain , electrically connected to the gate of the first transistor, with the other of the source or drain being the A third transistor electrically connected to a capacitor for holding charge according to the data. The third transistor has a metal oxide in the channel formation region, and is a semiconductor It is a device.

[0009] In one embodiment of the present invention, the second transistor has a metal oxide in the channel formation region. A semiconductor device having this feature is preferred.

[0010] In one embodiment of the present invention, the first transistor has silicon in the channel formation region A semiconductor device is preferred.

[0011] In one embodiment of the present invention, the first wiring is the same wiring as the second wiring in a semiconductor device. It is preferable.

[0012] One aspect of the present invention is an electronic device having the above-described semiconductor device and a housing.

[0013] One aspect of the present invention is a method for operating the semiconductor device described above, wherein the second transistor and a data writing operation that puts the third transistor into a conductive state, and the third transistor A data holding operation that puts the second transistor into a non-conductive state, and A data readout operation that causes the third transistor to enter a conductive state, and a semiconductor device This is how it works.

[0014] Further aspects of the present invention will be described in the following embodiments, and It is shown in the drawing. [Effects of the Invention]

[0015] According to one embodiment of the present invention, a semiconductor device functions as a memory device utilizing a very small off-current. In this regard, the objective is to provide a semiconductor device with excellent reliability, such as the ability to retain data for extended periods, and This can provide a semiconductor device that excels in low power consumption.

[0016] The description of multiple effects does not preclude the existence of other effects. Furthermore, one embodiment of the present invention is It is not necessarily required to have all of the effects exemplified. Furthermore, with respect to one embodiment of the present invention, For issues, effects, and novel features other than those mentioned above, please refer to the description and drawings in this specification. It will become clear eventually. [Brief explanation of the drawing]

[0017] [Figure 1] Figures 1A and 1B are circuit diagrams and timing charts showing example configurations of semiconductor devices. [Figure 2] Figures 2A and 2B are circuit diagrams showing examples of semiconductor device configurations. [Figure 3] Figures 3A and 3B are circuit diagrams showing example configurations of semiconductor devices. [Figure 4] Figures 4A and 4B are circuit diagrams showing example configurations of semiconductor devices. [Figure 5] Figures 5A and 5B are circuit diagrams showing example configurations of semiconductor devices. [Figure 6] Figure 6 is a circuit diagram showing an example of a semiconductor device configuration. [Figure 7] Figures 7A and 7B are circuit diagrams showing example configurations of semiconductor devices. [Figure 8] Figures 8A and 8B are circuit diagrams showing example configurations of semiconductor devices. [Figure 9] Figures 9A, 9B, and 9C are circuit diagrams showing example configurations of semiconductor devices. [Figure 10] Figure 10 is a circuit diagram showing an example of a semiconductor device configuration. [Figure 11] Figure 11 is a timing chart showing an example of the operation of a semiconductor device. [Figure 12] Figure 12 is a circuit diagram showing an example of a semiconductor device configuration. [Figure 13] Figure 13 is a timing chart showing an example of the operation of a semiconductor device. [Figure 14] Figure 14 is a circuit diagram showing an example of the configuration of a semiconductor device. [Figure 15] Figure 15 is a schematic cross-sectional diagram illustrating an example of the configuration of a semiconductor device. [Figure 16] Figure 16 is a schematic cross-sectional diagram illustrating an example of the configuration of a semiconductor device. [Figure 17] Figures 17A, 17B, and 17C are schematic cross-sectional diagrams illustrating examples of transistor configurations. [Figure 18] Figures 18A and 18B are schematic cross-sectional diagrams illustrating an example of transistor configuration. [Figure 19] Figure 19 is a schematic cross-sectional diagram illustrating an example of the configuration of a semiconductor device. [Figure 20] Figure 20 is a block diagram showing an example of a storage device configuration. [Figure 21] Figure 21 is a block diagram showing an example of a memory cell array configuration. [Figure 22] Figures 22A and 22B illustrate an example of an electronic component. [Figure 23] Figure 23 shows an example of an electronic device. [Modes for carrying out the invention]

[0018] Embodiments of the present invention will be described below. However, one embodiment of the present invention is not limited to the following description. The invention is not defined, and its form and details may vary without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that this can be changed. Therefore, one embodiment of the present invention is The description of the embodiments shown below shall not be interpreted as being limited to the following.

[0019] In this specification, the ordinal numbers "1st," "2nd," and "3rd" refer to the constituent elements. This is added to avoid confusion. Therefore, it does not limit the number of constituent elements. Furthermore, this does not limit the order of the components. Also, for example, the embodiments described herein The component referred to as "first" in one is in another embodiment or in the claims. It may also be the component referred to in "Second" in [the relevant section]. Furthermore, for example, in this specification, etc. In one embodiment, the component referred to as "first" is used in other embodiments, or It may be omitted in the claims.

[0020] In the drawing, elements that are identical or have similar functions, elements made of the same material, or Elements formed simultaneously may be assigned the same reference numeral, and the explanation of this repetition is omitted. It may happen.

[0021] In this specification, for example, the power supply potential VDD may be abbreviated as potential VDD, VDD, etc. This can happen. This is due to other components (e.g., signals, voltages, circuits, elements, electrodes, wiring). The same applies to (etc.).

[0022] Furthermore, when using the same sign for multiple elements, especially when it is necessary to distinguish between them... The symbols are followed by identification codes such as "_1", "_2", "[n]", and "[m,n]". In some cases, it may be written as follows: For example, the second wiring GL may be written as wiring GL[2].

[0023] (Embodiment 1) A configuration example of a semiconductor device and an operating method of the semiconductor device according to one aspect of the present invention is shown in Figure This will be explained with reference to Figures 1 through 14.

[0024] Figure 1A shows an example of a circuit diagram of a semiconductor device. The semiconductor device 10 shown in Figure 1A is It has transistor 11, transistor 12, transistor 13, and capacitor 14. do.

[0025] The gate of transistor 11 is connected to the wiring WWL. The source of transistor 11 is One side of the drain is connected to the gate of transistor 13, and the source or of transistor 12. It is connected to one side of the drain. The other side of the source or drain of transistor 11 is connected to wiring B. It is connected to L. Note that in Figure 1A and in the description herein, the sole of transistor 11 The drain or the other side, the gate of transistor 13, and the source of transistor 12 Alternatively, the node to which one of the drains is connected is called node MN1.

[0026] The gate of transistor 12 is connected to the wiring RWL. The source of transistor 12 is The other end of the drain is connected to one electrode of capacitor 14. The electrodes are connected to wiring CL. Note that in Figure 1A and in the description herein, The source or drain of the converter 12 and one electrode of the capacitor 14 are connected. The node that is connected is called node MN2. Note that wiring CL is wiring to which a fixed potential is applied.

[0027] Note that the capacitance value of capacitor 14 (capacitance value of node MN2) is the same as that of transistor 13. It is preferable to have a configuration that is larger than the node capacity (capacity value of node MN1). Configuration shown in Figure 1A So, when reading data from semiconductor device 10, the data is sent from node MN2 to node MN1. The configuration involves writing back the data and then reading it. Therefore, the capacity value of node MN1 is read from node M By keeping the capacitance value of N2 lower, the amount of charge required when writing back data is reduced. It is possible.

[0028] Either the source or drain of transistor 13 is connected to wiring RL. The source or drain of terminal 13, the other of which is connected to wiring SL.

[0029] Transistor 12 controls the voltage at node MN1 according to the voltage applied to wiring RWL. It has a function to control whether or not to transmit to node MN2. Transistor 12 is connected to wiring R The voltage supplied to node MN2 is held in capacitor 14 according to the voltage supplied to WL. It has the function of conducting according to the voltage applied to the wiring RWL. Transistor 12 conducts according to the voltage applied to the wiring RWL. Alternatively, it can function as a switch that toggles between a non-conductive state (also called on or off). It is possible.

[0030] As transistor 12, a transistor having an oxide semiconductor in the channel formation region ( It is preferable that the configuration below is composed of an OS transistor. By using a memory element with an OS transistor, the source and drain are controlled when the device is off. By taking advantage of the extremely low leakage current (hereinafter referred to as off-current) flowing between the inputs, the desired voltage can be obtained. This can be stored in a memory element.

[0031] Transistor 12 is a transistor in which the channel formation region is an oxide semiconductor (hereinafter, It is preferable that it is composed of an OS transistor. In one embodiment of the present invention, O By using an S transistor as transistor 12, when in a non-conductive state (off) By utilizing the fact that the leakage current (hereinafter referred to as off-current) flowing between the source and drain is extremely low to hold an electric charge in the capacitor 14 corresponding to the data written to the semiconductor device 10. This can be done. In other words, a charge holding circuit 1 composed of transistor 12 and capacitor 14 In step 5, the data written to the semiconductor device 10 can be retained for a long period of time.

[0032] In addition, the charge retention circuit 15 using an OS transistor charges or discharges the charge. This allows for data rewriting and reading, effectively limiting the number of data rewrites and reads. It is possible to write to and read from it. The charge holding circuit 15 using an OS transistor is , unlike magnetic memory or resistive random-access memory, which do not involve structural changes at the atomic level. Therefore, it has excellent rewrite endurance. Also, the charge holding circuit 15 using an OS transistor is Even with repeated rewrite operations like flash memory, instability can occur due to an increase in electron trapping centers. That is not permitted.

[0033] Furthermore, the charge retention circuit 15 using an OS transistor has a channel formation region made of silicon. It can be freely placed on circuits using such transistors (hereinafter referred to as Si transistors). Therefore, integration can be easily performed. Also, OS transistors are Si transistors Since it can be manufactured using similar manufacturing equipment, it can be produced at a low cost.

[0034] Furthermore, in addition to the gate electrode, source electrode, and drain electrode, the OS transistor also has a battery Including a gate electrode allows for a 4-terminal semiconductor element. Depending on the voltage applied to the gate electrode, the input and output of the signal flowing between the source and drain are independent. It can be constructed using a controllable electrical circuit network. Therefore, the circuit design can be done using the same approach as with LSIs. It is possible to perform calculations. In addition, OS transistors can be used in high-temperature environments. It has superior electrical properties compared to standard. Specifically, it is suitable for high temperatures between 125°C and 150°C. Even at high temperatures, the ratio of on-current to off-current is large, resulting in good switching operation. It is possible.

[0035] The materials used in Si transistors include single-crystal silicon and non-single-crystal silicon. For example, polycrystalline silicon can be used. Single-crystal silicon can be used in Si transistors. When using this, the current flowing between the source and drain when it is turned on (also called the on-current) is increased. It can be heard. In addition to silicon, germanium (Ge) can also be used as a material for semiconductor layers. ) such semiconductors, GaAs, InP, SiC, ZnSe, GaN, SiGe, etc. Compound semiconductors can also be used.

[0036] Transistor 11 supplies a voltage to wiring WWL corresponding to the data supplied to wiring BL. It has a function to control whether or not to transmit the signal to node MN1 depending on the voltage. T11 is either conducting or non-conducting (on or off) depending on the voltage applied to the wiring WWL. It can function as a switch that can toggle between "off" and "off".

[0037] Furthermore, when using a Si transistor as a switch, the "conductivity state" of the transistor and This is a state where the source and drain electrodes of a transistor can be considered to be electrically short-circuited. This refers to the state in which a transistor is "non-conducting," where the source electrode and the drain electrode of the transistor are connected. This refers to a state in which the electrodes can be considered electrically disconnected.

[0038] The data provided to wiring BL shall be binary data, either data '1' or data '0'. It can be represented as follows. Data '1' or data '0' is written according to the level of the electric potential. This is a signal. The data '1' is held at node MN2 and then released from node MN2. The charge is distributed to MN1, which generates enough current in transistor 12 to allow data to be read. This is the potential for flowing. The data '0' is held in node MN2, and then in node MN2 The potential is set to prevent current from flowing through transistor 12 when charge is distributed from node MN1. be.

[0039] Transistor 13, depending on the potential of node MN1, between the source electrode and the drain electrode It has the function of controlling the amount of current flowing through it. Wiring RL is charged by the precharge circuit. After being given (pre-charged), the potential changes according to the amount of current flowing through transistor 13. This is a dynamic wiring. Wiring SL flows to transistor 13 in accordance with the potential of node MN1. This is wiring that provides a potential to control the amount of current being drawn.

[0040] By using the configuration shown in Figure 1A, data can be rewritten by charging or discharging electric charge. Because read / write operations become possible, there are virtually unlimited data write and read operations. It is possible. Discharging the retained charge during data retrieval, so-called destruction. Because data can be read without reading it, the power required for data refresh is reduced. This reduces the power consumption associated with charging and discharging the battery.

[0041] Furthermore, by using the configuration shown in Figure 1A, the capacity value of node MN1 is smaller than the capacity value of node MN2. Because of this, the amount of charge required when writing back data can be reduced. It is possible to read data without discharging the held charge into wiring with high capacitance. It is possible. Also, by increasing the capacity value of node MN2, it is possible to maintain data for long periods of time. This allows for the creation of highly reliable semiconductor devices.

[0042] Figure 1B shows a timing chart to illustrate an example of the operation of the semiconductor device shown in Figure 1A. In Figure 1B, wiring WWL, wiring RWL, wiring BL, wiring RL, wiring SL, node MN1 , and the potential fluctuations corresponding to data writing and reading in node MN2 are schematically represented. This is illustrated in detail. In Figure 1B, the period is divided into periods T1 to T9, and the period T1 to T3 is the data writing period, period T4 is the data retention period, and periods T5 through T9 are data This corresponds to the readout period. Also, in Figure 1B, the data is illustrated as signals of '1' and '0'. Furthermore, in the description of the operation example of the semiconductor device 10, the conduction state or non-conduction state of the transistor The potential of the wiring to which the state-controlling signal is applied can be described as a high-level or low-level potential. do.

[0043] Furthermore, Figures 2 to 6 simulate the operation of the semiconductor device 10 during the period T1 to T9 in Figure 1B. These are diagrams for formulaic explanation. In Figures 2 to 6, solid arrows indicate wiring or This schematically represents the flow of signals input and output between the codes. Also, in Figures 2 to 6, To facilitate understanding of the circuit diagram, non-conducting transistors are marked with an "X". .

[0044] Period T1 in Figure 1B is the period during which data writing operations are performed. As shown in Figure 2A With wiring WWL at a high level and wiring RWL at a high level, transistor 11 and transistor Station 12 is set to conduct. In wiring BL, potentials corresponding to data '1' and '0' are applied. The potential is then applied to nodes MN1 and MN2. Wiring RL and wiring SL are Assuming the same potential, no current flows through transistor 13.

[0045] The period T2 in Figure 1B is the period during which data writing operations are performed. As shown in Figure 2B... The potentials of nodes MN1 and MN2 will correspond to the data values ​​'1' and '0'. .

[0046] Period T3 in Figure 1B is the period during which data writing operations are performed. As shown in Figure 3A. Set wiring WWL to H level and wiring RWL to L level, and set transistor 11 to conduction. The transistor 12 is de-conducted. Node MN2 transmits electricity according to data '1' and '0'. The position is maintained. At node MN1, the potential corresponding to data '1' and '0' is discharged to the wiring BL. And eventually, the potential becomes L level.

[0047] Period T4 in Figure 1B is the period during which data is retained, as shown in Figure 3B. Wiring W Set WL to L level, wiring RWL to L level, and transistor 11 to a non-conductive state. Station 12 is de-conductive. Node MN2 maintains potentials corresponding to data '1' and '0'. It is maintained. At node MN1, the potential during period T3, i.e., the L level, is maintained. Node MN The potential of 2 is distributed by making both transistor 11 and transistor 12 non-conductive. This makes it less likely for discharge to occur in line BL.

[0048] Period T5 in Figure 1B is the period during which the data retrieval operation is performed. As shown in Figure 4A. Set wiring WWL to L level and wiring RWL to L level, and set transistor 11 to a non-conductive state. Transistor 12 is made non-conductive. Wiring RL is set to a predetermined potential, for example, a high potential. Precharge it (indicated as "precharge" in the diagram).

[0049] Period T6 in Figure 1B is the period during which the data retrieval operation is performed. As shown in Figure 4B. Set wiring WWL to L level and wiring RWL to H level, and set transistor 11 to a non-conductive state. Transistor 12 is made to conduct. The charge held at node MN2 is divided to node MN1. The nodes MN1 and MN2 are arranged so that their potentials correspond to data '1' and '0'. The capacitance value of node MN1 is smaller than that of node MN2, therefore, in relation to the distribution of charge... The potential fluctuations can be reduced. In transistor 13, the potential of node MN1, In other words, the current Iread depends on the data '1' and '0' held in the charge holding circuit 15. Current flows. Current Iread is when the potential of node MN1 is at the H level, i.e., data '1'. Larger, and smaller if the potential of node MN1 is at the L level, i.e., data '0'. Therefore, If the data is '1', the potential fluctuation of the pre-charged wiring RL is large, and the data is '0'. If so, the potential fluctuation of the pre-charged wiring RL will be small. Pre-charged during period T5 The potential of the charged wiring RL fluctuates depending on the magnitude of the current Iread.

[0050] Period T7 in Figure 1B is the period during which the data retrieval operation is performed. As shown in Figure 5A. In transistor 13, the current Iread flows depending on the potential of node MN1. If the data of MN1 is data '1', that is, if the potential is at the H level, then the current Iread is large. Therefore, the potential fluctuation of the pre-charged wiring RL is large. Conversely, node MN1 If the data is '0', that is, at an L level potential, then the current Iread is small (wiring (RL changes to L level). Therefore, the potential fluctuation of the pre-charged wiring RL is small. (The wiring RL remains at the H level). Therefore, the data written to the semiconductor device 10 The data can be read from the RL wiring.

[0051] Period T8 in Figure 1B is the period during which the data retrieval operation is performed. As shown in Figure 5B. Set wiring WWL to L level and wiring RWL to L level, and set transistor 11 to a non-conductive state. Transistor 12 is set to a non-conducting state. The potentials of nodes MN1 and MN2 are... The potential will be determined according to the values ​​of '1' and '0'.

[0052] Period T9 in Figure 1B is the period during which the data retrieval operation is performed, as illustrated in Figure 6. Set wiring WWL to high level and wiring RWL to low level, and transistor 11 to a conductive state. The inverter 12 is set to a non-conductive state. At node MN2, the potential corresponds to data '1' and '0'. This is maintained. At node MN1, a potential corresponding to data '1' or '0' is discharged to the wiring BL. At node MN1, the potential is the same as that of wiring BL, i.e., it is at the L level. The current Iread stops flowing.

[0053] In the configuration shown in Figure 1A, the operation method shown in Figures 1B, 2 to 6 allows for the charging of an electric charge or Because data can be rewritten and read by discharging, it is practically free A limited number of data write and read operations are possible. When reading data, By discharging the retained charge, it is possible to read data without destructive readout. Therefore, it reduces the power consumption required for charging and discharging the charge needed to refresh the data. It is possible.

[0054] Furthermore, in the configuration shown in Figure 1A, by using the operation methods shown in Figures 1B, 2 through 6, node M Because the capacitance value of N1 is smaller than the capacitance value of node MN2, the charge required to write the data back is The amount can be reduced. Therefore, the retained charge can be discharged into wiring with a large capacitance. Data can be read without any additional steps. Furthermore, the capacity value of node MN2 can be increased. This allows for the creation of a semiconductor device with excellent reliability, such as the ability to retain data for extended periods.

[0055] Furthermore, transistor 11, like transistor 12, can be an OS transistor. Yes, it is possible. OS transistors can be freely placed on circuits using Si transistors, etc. Therefore, integration can be easily performed. Also, OS transistors are Si transistors Since it can be manufactured using the same manufacturing equipment as T, it can be produced at low cost. In Figure 7A, transistors 11A and 12 of semiconductor device 10A are shown. To clearly indicate that A is an OS transistor, the sign for OS is included. Furthermore, to clearly indicate that transistor 13A is a Si transistor, the Si symbol is used. The numbers are assigned together.

[0056] Note that transistor 11, like transistor 13, can be a Si transistor. Yes, it is possible. In Figure 7B, the transistor 12B of the semiconductor device 10B is an OS transistor. To clearly indicate that it is a transistor, the OS designation is added. To make it clear that transistors 11B and 13B are Si transistors, S The sign of 'i' is aligned.

[0057] In Figure 7A, transistors 11A and 12A of semiconductor device 10A are The diagram shows a transistor with a top-gate or bottom-gate structure that lacks a gate electrode. However, the structure of transistors 11A and 12A is not limited to this. For example, Figure 8A shows... As shown in semiconductor device 10C, the back gate is connected to the back gate electrode wire BGL. Transistors 11C and 12C having electrodes may also be used. 13C is a Si transistor. By using the configuration shown in Figure 8A, transistor 11C is approximately Furthermore, it is possible to easily control the electrical characteristics of transistor 12C, such as the threshold voltage, from an external source. can.

[0058] Alternatively, as shown in the semiconductor device 10D in Figure 8B, a back gate is connected to the gate electrode. Transistors 11D and 12D may also be transistors having gate electrodes. Zista 13D is a Si transistor. By using the configuration shown in Figure 8B, transistor 11 This allows us to increase the amount of current flowing through D and transistor 12D.

[0059] In Figure 7A, the transistor 13A of the semiconductor device 10A is an n-channel type transistor. Although illustrated as a transistor, the conductivity type of transistor 13A is not limited to this. For example, As shown in Figure 9A, the semiconductor device 10E is a p-channel type transistor 13E. Transistors 11E and 12E are n-channel type OS transistors. He is a genista.

[0060] In Figure 7B, transistors 11B and 1 Although 3B is shown as an n-channel transistor, transistors 11B and 3B are also shown. The conductivity type of the converter 13B is not limited to this. For example, semiconductor device 10F shown in Figure 9B As shown above, p-channel type transistors 11F and 13F can be used. The ZISTA12F is an n-channel OS transistor.

[0061] In Figure 7B, transistors 11B and 1 Although 3B is shown as a transistor of the same conductivity type, transistors 11B and TRAN are shown separately. The conductivity types of ZISTA 13B can be different. For example, the semiconductor device 10G shown in Figure 9C Therefore, we will use an n-channel transistor 11G and a p-channel transistor 13G. It is possible. Transistor 12G is an n-channel OS transistor.

[0062] The semiconductor device 10 can be arranged in a matrix. Figure 10 shows the same configuration as in Figure 1A. Figure 1 illustrates an example configuration when the semiconductor device 10 is arranged in a 2x2 matrix. In figure 0, the semiconductor device 10 is shown as semiconductor device 10_1 to 10_4. Furthermore, in Figure 10, the wiring connected to each semiconductor device 10_1 to 10_4 is shown as wiring RW. L_1, RWL_2, Wiring WWL_1, WWL_2, Wiring RL_1, RL_2, Wiring BL _1, BL_2, and wiring SL_1, SL_2 are illustrated.

[0063] Figure 11 shows a timing chart illustrating an example of operation in the configuration shown in Figure 10. Figure T is shown. Note that details of the timing chart shown in Figure 11 overlap with Figure 1B. Therefore, the explanation will be omitted.

[0064] In the configuration shown in Figure 10, the functions of different wires are made common to reduce the number of wires. This can be achieved. As an example, in Figure 12, the wiring RL_1 and RL_2 in Figure 10 By operating in a way that combines the functions of wiring SL_1 and SL_2, wiring SL_1, The diagram shows an example configuration where SL_2 is omitted. In other words, wiring RL is the same wiring as wiring SL. By operating it in this manner, the number of wires can be reduced.

[0065] Figure 13 shows a timing chart illustrating an example of operation in the configuration shown in Figure 12. Figure T is shown. Note that the timing chart shown in Figure 13 is the same as the timing chart shown in Figure 11. The difference is that when writing data to the semiconductor device on the first line, the other lines, for example... The difference is that the wiring in the second row, WWL_2, is set to L level. By using this configuration, The current flowing through transistor 13 during data writing can be suppressed. Details of the timing chart for the period are omitted as they overlap with Figure 1B.

[0066] As another example from Figure 12, Figure 14 shows the wiring SL_1 and SL_2 in Figure 10 and The diagram illustrates a configuration example where wiring SL_2 is omitted by operating the system to combine the functions of the two. In other words, by sharing wiring SL among multiple semiconductor devices, the number of wires can be reduced. It is possible.

[0067] In the configuration described in the embodiments described above, by charging or discharging the charge, Since data can be rewritten and read, there is virtually no limit to the number of data writes. And it is readable. When reading data, the held charge is discharged. Therefore, since data can be read without so-called destructive reading, data refresh is possible. This reduces the power consumption required for charging and discharging the battery.

[0068] Furthermore, in the configuration described in the above-described embodiment, the capacity value of node MN1 is node MN Because its capacitance value is smaller than 2, the amount of charge required when writing data back can be reduced. Therefore, the data can be read without discharging the retained charge into wiring with high capacitance, etc. It is possible to output data. Also, by increasing the capacity value of node MN2, data can be stored for a long time. This allows for the creation of highly reliable semiconductor devices.

[0069] (Embodiment 2) In this embodiment, the cross-sectional configuration example of the semiconductor device described in the above embodiment is shown in the drawings. We will explain using this method.

[0070] The semiconductor device shown in Figure 15 consists of transistor 13, transistor 12, and capacitor 1 It has 4 and . Figure 17A is a cross-sectional view of transistor 12 in the channel length direction, and Figure Figure 17B is a cross-sectional view of transistor 12 in the channel width direction, and Figure 17C is a cross-sectional view of transistor 1 This is a cross-sectional view of channel 3 in the channel width direction.

[0071] Transistor 12 is an OS transistor. Transistor 12 has a small off-current. Therefore, the power consumption of semiconductor devices can be reduced.

[0072] The semiconductor device described in this embodiment, as shown in Figure 15, has a transistor 13, It has a transistor 12 and a capacitor 14. Transistor 12 is above transistor 13. The capacitor 14 is provided above the transistors 13 and 12. It is being done.

[0073] The transistor 13 is provided 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, a low-resistance region that functions as a source region or drain region. It has a resistance region 314a and a low resistance region 314b.

[0074] As shown in Figure 17C, transistor 13 is located on the upper surface of semiconductor region 313 and channel The sides in the width direction are covered by the conductor 316 via the insulator 315. In this way, By making ZISTA13 a Fin type, the effective channel width is increased. This allows, The on-characteristics of transistor 13 can be improved. Also, the contribution of the electric field of the gate electrode. This allows the value to be increased, thereby improving the off-mode characteristics of transistor 13.

[0075] Note that transistor 13 can be either a p-channel or n-channel type.

[0076] The region where the channel of the semiconductor region 313 is formed and the region near it, as well as the source region Alternatively, in the low-resistance region 314a and low-resistance region 314b, which are drain regions, It is preferable that it contains semiconductors such as silicon-based semiconductors, and it is preferable that it contains single-crystal silicon. These are Ge (germanium), SiGe (silicon germanium), and GaAs (gallium hydrogen). It may also be formed from a material containing (aluminum), GaAlAs (gallium aluminum arsenide), etc. This silicon uses a structure in which the effective mass is controlled by applying stress to the crystal lattice and changing the lattice spacing. This configuration may also be used. Alternatively, by using GaAs and GaAlAs, transistor 13 can be configured HEMT (High Electron Mobility Transistor) and You may do so.

[0077] 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, are used. Contains elements that confer properties.

[0078] 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, and gold Conductive materials such as metal alloys, alloy materials, or metal oxide materials can be used.

[0079] Furthermore, since the work function is determined by the material of the conductor, the material of the conductor must be selected accordingly. This allows you to adjust the threshold voltage of the transistor. Specifically, by using nitride in the conductor... It is preferable to use materials such as tan or tantalum nitride. Furthermore, it is desirable to achieve both conductivity and embedding properties. To achieve this, metal materials such as tungsten and aluminum are used in layers as conductive materials. Preferably, and especially preferably, tungsten is used in terms of heat resistance.

[0080] Note that the transistor 13 shown in Figure 15 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. For example, a semiconductor device can use an OS transistor. When using a unipolar circuit consisting only of transistors, the configuration of transistor 13 is as shown in Figure 16. Therefore, the same configuration as transistor 12, which is an OS transistor, should be used. Details about Sta12 will be explained later.

[0081] In this specification, a unipolar circuit is defined as, for example, a circuit in which all transistors are of the same polarity. This shows a standard circuit. For example, all transistors are n-channel transistors. The circuit can be described as a unipolar circuit.

[0082] The transistor 13 is covered by insulator 320, insulator 322, insulator 324, and insulator 326 is arranged in a sequential stack.

[0083] 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.

[0084] In this specification, silicon oxidnitride refers to a material whose composition contains more oxygen than nitrogen. It refers to materials with a high content of nitrogen, and silicon nitride, in terms of its composition, contains more nitrogen than oxygen. This indicates a material with a high concentration of [amount]. Furthermore, in this specification, aluminum oxide nitride is referred to as [component]. It refers to a material in which the oxygen content is higher than the nitrogen content, and aluminum nitride oxide is a combination of these materials. This refers to materials with a higher nitrogen content than oxygen content.

[0085] The insulator 322 smooths out the step created by the transistor 13 and the like located below it. It may also function as a planarizing film. For example, the upper surface of the insulator 322 is flat To improve performance, the surface is planarized using chemical mechanical polishing (CMP) or similar methods. That's fine.

[0086] Furthermore, the insulator 324 receives the substrate 311 or the transistor 13, etc. In the region where 2 is provided, a membrane with barrier properties that prevents the diffusion of hydrogen and impurities is used. This is preferable.

[0087] As an example of a film that has barrier properties against hydrogen, for example, silica nitride formed by CVD A semiconductor can be used. Here, a semiconductor having an oxide semiconductor such as transistor 12 can be used. Hydrogen diffusion into the device can degrade the properties of the semiconductor device. Therefore By using a film that suppresses hydrogen diffusion between transistor 12 and transistor 13... This is preferable. Specifically, a membrane that suppresses hydrogen diffusion is a membrane that has a low rate of hydrogen desorption. ru.

[0088] The amount of hydrogen desorbed can be analyzed, for example, using a thermal desorption gas analysis method (TDS). For example, the amount of hydrogen desorption from insulator 324 is determined in TDS analysis when the film surface temperature is 5 In the range of 0°C to 500°C, the amount of desorption converted to hydrogen atoms is per unit area of ​​insulator 324. Convert to units, 10 x 10 15 atoms / cm 2 The following is preferably 5 × 10 15 at oms / cm 2 The following is acceptable.

[0089] Furthermore, it is preferable that the dielectric constant of the insulator 326 is lower than that of the insulator 324. For example, The relative permittivity of the edge material 326 is preferably less than 4, and more preferably less than 3. Also, for example, an insulator... The relative permittivity of 326 is preferably 0.7 times or less, and preferably 0.6 times or less, than the relative permittivity of the insulator 324. This is 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.

[0090] Furthermore, capacitors are present in insulators 320, 322, 324, and 326. 14, or a conductor 328 and a conductor 330, etc., which are connected to the transistor 12 are embedded. Furthermore, conductors 328 and 330 have the function of a plug or wiring. Furthermore, a conductor that functions as a plug or wiring may combine multiple structures into the same Symbols may be assigned. Also, in this specification, etc., wiring and plugs connected to the wiring are used. The two may be a single unit. That is, a part of the conductor may function as wiring, and the conductor In some cases, a part of the electrical device may function as a plug.

[0091] The materials for each plug and wiring (conductor 328, conductor 330, etc.) are metal materials, composite materials, etc. Conductive materials such as gold materials, metal nitride materials, or metal oxide materials are used in a single layer or in a laminated form. This is possible. High-melting-point materials such as tungsten and molybdenum that offer both heat resistance and conductivity. It is preferable to use aluminum or copper. It is preferable to form it with a low-resistance conductive material such as the following. By using a low-resistance conductive material, wiring The resistance can be reduced.

[0092] A wiring layer may be provided on the insulator 326 and the conductor 330. For example, as shown in Figure 15 Insulators 350, 352, and 354 are arranged in a sequential stack. Furthermore, a conductor 356 is formed on insulators 350, 352, and 354. The conductor 356 functions as a plug or wiring to connect to the transistor 13. The conductor 356 is provided using the same material as the conductor 328 or the conductor 330. It is possible.

[0093] Furthermore, 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 to include a conductor. In particular, it is preferable to include a conductor in the insulator 350 which has barrier properties against hydrogen. A conductor having a barrier property against hydrogen is formed in the opening that is cut. Transistor 13 and transistor 12 can be separated by a barrier layer, This can suppress the diffusion of hydrogen from transistor 13 to transistor 12.

[0094] For example, tantalum nitride can be used as a conductor that has barrier properties against hydrogen. It would be good to do so. Also, by laminating tantalum nitride and highly conductive tungsten, the wiring can be made This allows for the suppression of hydrogen diffusion from transistor 13 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.

[0095] A wiring layer may be provided on the insulator 354 and the conductor 356. For example, as shown in Figure 15 Insulators 360, 362, and 364 are arranged in a sequential stack. Furthermore, a conductor 366 is formed on insulators 360, 362, and 364. Conductor 366 has the function of a plug or wiring. It can be provided using the same material as body 328 or conductor 330.

[0096] Furthermore, 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 to include a conductor. In particular, it is preferable to include a conductor in the insulator 360 which has barrier properties against hydrogen. A conductor having a barrier property against hydrogen is formed in the opening that is cut. Transistor 13 and transistor 12 can be separated by a barrier layer, This can suppress the diffusion of hydrogen from transistor 13 to transistor 12.

[0097] A wiring layer may be provided on the insulator 364 and the conductor 366. For example, as shown in Figure 15. Insulators 370, 372, and 374 are arranged in a sequential stack. Furthermore, a conductor 376 is formed on insulators 370, 372, and 374. The conductor 376 functions as a plug or wiring. It can be provided using the same material as body 328 or conductor 330.

[0098] Furthermore, for example, insulator 370, like insulator 324, has barrier properties against hydrogen. It is preferable to use an insulator. Furthermore, the conductor 376 has barrier properties against hydrogen. It is preferable to include a conductor. In particular, it is preferable to include a conductor in the insulator 370 which has barrier properties against hydrogen. A conductor having a barrier property against hydrogen is formed in the opening that is cut. Transistor 13 and transistor 12 can be separated by a barrier layer, This can suppress the diffusion of hydrogen from transistor 13 to transistor 12.

[0099] A wiring layer may be provided on the insulator 374 and the conductor 376. For example, as shown in Figure 15 Insulators 380, 382, ​​and 384 are arranged in a sequential stack. Furthermore, a conductor 386 is formed on insulators 380, 382, ​​and 384. Conductor 386 functions as a plug or wiring. It can be provided using the same material as body 328 or conductor 330.

[0100] For example, insulator 380, like insulator 324, has barrier properties against hydrogen. It is preferable to use an insulator. Furthermore, the conductor 386 has barrier properties against hydrogen. It is preferable to include a conductor. In particular, it is preferable to include a conductor in the insulator 380 which has barrier properties against hydrogen. A conductor having a barrier property against hydrogen is formed in the opening that is cut. Transistor 13 and transistor 12 can be separated by a barrier layer, This can suppress the diffusion of hydrogen from transistor 13 to transistor 12.

[0101] In the above, a wiring layer containing a conductor 356, a wiring layer containing a conductor 366, and a conductor 376 A wiring layer including and a wiring layer including the conductor 386 have been described, but 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.

[0102] Insulator 384 has insulators 510, 512, 514, and 516. They are arranged in a stack in order. Insulator 510, insulator 512, insulator 514, and insulation It is preferable that one of the components 516 is a material that has barrier properties against oxygen and hydrogen. .

[0103] For example, the insulators 510 and 514 are made from the substrate 311, or from the transistor 1 To prevent hydrogen and impurities from diffusing from the area where 3 is installed to the area where transistor 12 is installed. It is preferable to use a film with good barrier properties. Therefore, a material similar to that of insulator 324 is preferable. It is preferable to use [this].

[0104] As an example of a film with hydrogen barrier properties, silicon nitride formed by CVD is used. It is possible to do this. Here, water is added to a semiconductor device having an oxide semiconductor such as transistor 12. The diffusion of the element can degrade the properties of the semiconductor device. Therefore, It is preferable to use a film that suppresses hydrogen diffusion between the zista 12 and the transistor 13. Specifically, a membrane that suppresses hydrogen diffusion is a membrane that releases less hydrogen.

[0105] 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. This is preferable.

[0106] In particular, aluminum oxide reacts with oxygen and hydrogen, which are factors that cause variations in the electrical properties of transistors. It has a high barrier effect that prevents both moisture and other impurities from passing through the film. Therefore, oxidation Aluminum is subject to impurities such as hydrogen and water during and after the transistor manufacturing process. This prevents contamination of transistor 12. This can suppress the release of oxygen from the metal oxide. Therefore, transistor 12 It is suitable for use as a protective film against [unclear].

[0107] Furthermore, for example, the same material as the insulator 320 is used for insulators 512 and 516. It is possible to do so by applying materials with relatively low dielectric constants to these insulators. This can reduce parasitic capacitance between wirings. For example, insulator 512 and insulator For 516, silicon oxide films, silicon oxide nitride films, and the like can be used.

[0108] Furthermore, insulators 510, 512, 514, and 516 contain a conductive material 5 18, and a conductor (for example, conductor 503) that constitutes the transistor 12 are embedded. The conductor 518 is connected to the capacitor 14 or the transistor 13. It has the function of a wire or a conductor. Conductor 518 is conductor 328 or conductor 330 It can be provided using the same materials as above.

[0109] 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, The zista 13 and transistor 12 are connected by a layer that provides barrier properties against oxygen, hydrogen, and water. This allows for separation and suppresses the diffusion of hydrogen from transistor 13 to transistor 12. It is possible.

[0110] A transistor 12 is provided above the insulator 516.

[0111] As shown in Figures 17A and 17B, the transistor 12 has an insulator 514 and an insulator 51 A conductor 503 is positioned to be embedded in 6, and on 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 , oxide 530b placed on oxide 530a, and oxide 530b spaced apart from each other The arranged conductors 542a and 542b, and on conductors 542a and 542b An insulator 5 is placed and superimposed between the conductor 542a and the conductor 542b, with an opening formed therein. 80, oxide 530c arranged on the bottom and sides of the opening, and on the forming surface of the oxide 530c It comprises an arranged insulator 550 and a conductor 560 arranged on the forming surface of the insulator 550. ru.

[0112] Also, as shown in FIGS. 17A and 17B, it is preferable to dispose an insulator 544 between the oxides 530a, 530b, the conductors 5 42a, and 542b and the insulator 580. Also, as shown in FIGS. 17A and 17B, the conductor 560 preferably includes a conductor 560a provided inside the insulator 550 and a conductor 560b provided so as to be embedded inside the conductor 560a. Also, as shown in FIGS. 17A and 17B, it is preferable that an insulator 574 is disposed on the insulator 580, the conductor 560, and the insulator 550. In the following, the oxides 5, 30a, 530b, and 530c may be collectively referred to as an oxide 530.

[0113] In the transistor 12, a structure in which three layers of the oxides 530a, 530b, and 530c are laminated in a region where a channel is formed and in its vicinity is shown, but the present invention is not limited to this. For example, a single layer of the oxide 530b, a two-layer structure of the oxide 530b and the oxide 530a, a two-layer structure of the oxide 530b and the oxide 530c, or a laminated structure of four or more layers may be provided. Also, in the transistor 12, the conductor 560 is shown as a two-layer laminated structure, but the present invention is not limited to this. For example,

[0114] the conductor 560 may have a single-layer structure or a laminated structure of three or more layers. Also, the transistor 12 shown in FIGS. 15, 16, 17A, and 17B is an example, and the present invention is not limited to its structure. An appropriate transistor may be used according to the circuit configuration and driving method.

[0115] ​​​​​​​​​Here, conductor 560 functions as the gate electrode of transistor 12, and conductor 542 a and conductor 542b function as a source electrode or a drain electrode, respectively. Thus, 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. That is, In transistor 12, the gate electrode is self-aligned between the source electrode and the drain electrode. It can be positioned in this way. Therefore, the conductor 560 can be positioned with a margin. Since it can be formed without any issues, the occupied area of ​​the transistor 12 can be reduced. This makes it possible to miniaturize and highly integrate semiconductor devices.

[0116] Furthermore, the conductor 560 is self-aligned in the region between conductor 542a and conductor 542b. As a result, the conductor 560 has a region that overlaps with the conductor 542a or the conductor 542b. It does not have. As a result, between conductor 560 and conductors 542a and 542b, The parasitic capacitance that is formed can be reduced. Therefore, the switching of transistor 12 Speed ​​can be improved, and high frequency characteristics can be achieved.

[0117] 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. There are cases where this is the case. In that case, the potential applied to conductor 503 is the same as the potential applied to conductor 560. By changing them independently without linking them, the threshold voltage of transistor 12 can be controlled. This can be done. In particular, by applying a negative potential to the conductor 503, the transistor 12 By increasing the threshold voltage above 0V, it becomes possible to reduce the off-current. Therefore, Applying a negative potential to conductor 503 is more effective than not applying a negative potential to conductor 560. This allows us to reduce the drain current when the potential is 0V.

[0118] The conductor 503 is arranged to have a region that overlaps 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 The electric field generated from and the electric field generated from the conductor 503 connect and form in the oxide 530. It can cover the channel-forming region. In this specification, the first gate electrode, and The channel formation region of the transistor is electrically surrounded by the electric field of the second gate electrode. This structure is called a surrounded channel (s-channel) structure.

[0119] Furthermore, the conductor 503 has the same configuration as the conductor 518, and the insulators 514 and 5 A conductor 503a is formed in contact with the inner wall of the 16 openings, and a conductor 503b is formed further inside. This has been done. In addition, in transistor 12, conductors 503a and 503b are stacked. The present invention describes a configuration such as the above, but is not limited thereto. For example, a conductor 503 may be provided as a single layer or as a laminated structure of three or more layers.

[0120] Here, the conductor 503a allows for the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, and copper atoms. It is preferable to use a conductive material that has a suppressive function (i.e., the above-mentioned impurities are less likely to permeate it). i. Or, a function that suppresses the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.). It is preferable to use a conductive material having (the above oxygen is less permeable). In the present specification and the like, the function of suppressing the diffusion of impurities or oxygen means the function of suppressing the diffusion of any one or all of the above impurities or the above oxygen.

[0121] For example, since the conductor 503a has the function of suppressing the diffusion of oxygen, it is possible to suppress the oxidation of the conductor 50 3b and the decrease in conductivity.

[0122] Further, when the conductor 503 also serves as a wiring function, the conductor 503b is preferably made of a highly conductive material mainly composed of tungsten, copper or aluminum. In that case, the conductor 503a does not necessarily have to be provided. Although the conductor 503b is shown as a single layer it may also have a laminated structure. For example, it may be a laminate of titanium or titanium nitride and the above conductive material .

[0123] The insulators 520, 522, and 524 have the function as a second gate insulating film .

[0124] Here, the insulator 524 in contact with the oxide 530 is preferably an insulator containing more oxygen than oxygen having a stoichiometric composition. That is, it is preferable that an excess oxygen region is formed in the insulator 524. By providing such an insulator containing excess oxygen in contact with the oxide 530, the oxygen deficiency in the oxide 530 can be reduced, and the reliability of the transistor 12 can be improved.

[0125] Specific examples of the insulator having an excess oxygen region include an acid from which some oxygen is desorbed by heating It is preferable to use an oxide material. An oxide that desorbs oxygen upon heating is an oxide film in which the desorbed amount of oxygen, converted to oxygen atoms, is 1.0×10 atoms / cm or more, preferably 1.0 18 ×10 3 atoms / cm or more, more preferably 2.0×10 19 atoms / cm 3 or more, and even more preferably 3.0×10 19 atoms / c m 3 or more, as determined by TDS (Thermal Desorption Spectroscopy) analysis. Note that the surface temperature of the film during the above TDS analysis is preferably in the range of 100°C or higher and 700°C or lower, or 100 20 ℃ or higher and 400°C or lower.

[0126] <00009??5>

[0127] It is also possible to perform one or more of heat treatment, microwave treatment, or RF treatment by contacting the insulator having the above excess oxygen region with the oxide 530. By performing this treatment, water or hydrogen in the oxide 530 can be removed. For example, in the oxide 530, a reaction occurs in which the bond of VoH is broken, or in other words, a reaction of "V O H→V O +H" occurs, enabling dehydrogenation. A part of the hydrogen generated at this time may be removed as H2O by combining with oxygen from the oxide 530 or the insulator near the oxide 530. Also, a part of the hydrogen may be diffused or captured (also referred to as gettering) by the conductor 542. The above microwave treatment can be performed using, for example, a device having a power source for generating high-density plasma.​​​​​​​Alternatively, it is preferable to use a device that has a power supply that applies RF to the substrate side. For example, oxygen By using a gas containing and a high-density plasma, high-density oxygen radicals are generated. It is possible to generate by applying RF to the substrate side. The oxygen radicals are efficiently introduced into oxide 530 or the insulator near oxide 530. This can be done. Furthermore, the above microwave treatment is performed at a pressure of 133 Pa or higher, preferably 2 The pressure should be 00 Pa or higher, more preferably 400 Pa or higher. Furthermore, microwave processing is performed. For example, oxygen and argon are used as gases introduced into the apparatus, with an oxygen flow rate ratio (O2 The concentration of (O2+Ar) should be 50% or less, preferably between 10% and 30%.

[0128] Furthermore, during the manufacturing process of transistor 12, the surface of oxide 530 is exposed. Heat treatment is preferable. This heat treatment is, for example, 100°C to 450°C. Preferably, the heat treatment should be carried out at a temperature of 350°C to 400°C. Furthermore, the heat treatment should also be performed using nitrogen gas. Or an inert gas atmosphere, or an oxidizing gas at 10 ppm or more, 1% or more, or 10% The process is carried out in an atmosphere containing the above. For example, heat treatment is preferably carried out in an oxygen atmosphere. By supplying oxygen to oxide 530, oxygen deficiency (V O This can help reduce ) and The heat treatment may be carried out under reduced pressure. Alternatively, the heat treatment may be carried out using nitrogen gas or an inert gas. After heat treatment in this atmosphere, an oxidizing gas is added at a concentration of 10 ppm or more to replenish the desorbed oxygen. The procedure may be carried out in an atmosphere containing 1% or more, or 10% or more. Alternatively, an oxidizing gas at 10 ppm may be used. After heat treatment in an atmosphere containing 1% or more, or 10% or more, nitrogen gas is continuously applied. Alternatively, the heat treatment may be carried out in an inert gas atmosphere.

[0129] Furthermore, by performing an oxygenation treatment on oxide 530, the oxygen deficiencies in oxide 530 are supplied. It is repaired by the oxygen that is used, in other words, "V O This promotes the reaction "+O → null". Furthermore, the hydrogen remaining in the oxide 530 and the hydrogen supplied to the oxide 530 By reacting with oxygen, the hydrogen can be removed as H2O (dehydrated). This causes the hydrogen remaining in oxide 530 to recombine with the oxygen vacancy and V O H is It is possible to prevent it from happening.

[0130] Furthermore, if the insulator 524 has an excess oxygen region, the insulator 522 will have oxygen (for example, acid It has the function of suppressing the diffusion of elementary atoms, oxygen molecules, etc. (meaning that the above oxygen does not easily permeate). preferable.

[0131] The insulator 522 has the function of suppressing the diffusion of oxygen and impurities, so the oxide 530 The oxygen present does not diffuse to the insulator 520 side, which is preferable. Also, the conductor 503 is This can suppress the reaction between the insulator 524 and the oxide 530 and the oxygen present in them.

[0132] The 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 Insulators containing so-called high-k materials such as Sr)TiO3(BST) are used in single layers or multilayer configurations. It is preferable to use it in this way. As transistors become smaller and more integrated, the gate insulating film Thinning the film can sometimes lead to problems such as leakage current. By using a high-k material as the insulator, the physical film thickness is maintained during transistor operation. This allows for a reduction in the gate potential.

[0133] In particular, it has the function of suppressing the diffusion of impurities and oxygen (the above-mentioned oxygen is less permeable). Using an insulator containing an oxide of either aluminum or hafnium, or both, which are insulating materials. It is desirable to use an insulator containing an oxide of either aluminum or hafnium, or both. Aluminum, hafnium oxide, or oxides containing aluminum and hafnium (hafnium It is preferable to use materials such as aluminum aluminate. When formed, the insulator 522 prevents the release of oxygen from the oxide 530 and the transistor 12 It functions as a layer that suppresses the incorporation of impurities such as hydrogen from the surrounding area into the oxide 530.

[0134] Alternatively, these insulators may contain, for example, aluminum oxide, bismuth oxide, or 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 laminated onto the edge body.

[0135] Furthermore, it is preferable that the insulator 520 is thermally stable. For example, silicon oxide and Silicon oxide nitride is preferred because it is thermally stable. Also, the insulation properties of high-k materials By combining the edge material with silicon oxide or silicon oxide nitride, thermal stability and specific induction can be achieved. A laminated insulator 520 with a high power efficiency can be obtained.

[0136] Note that in the transistor 12 shown in Figures 17A and 17B, the second gate consists of a three-layer stacked structure. Insulators 520, 522, and 524 are shown as insulating films. The second gate insulating film may have a single layer, two layers, or a stacked structure of four or more layers. In this case, the laminated structure is not limited to that made of the same material, but may also be made of different materials. .

[0137] The transistor 12 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, etc. It is preferable to use one or more metal oxides selected from the above. In particular, oxide 530 and The In-M-Zn oxide that can be applied is CAAC-OS (C-Axls Aligne d Crystal Oxide Semiconductor), CAC-OS(Cl oud-Aligned Composite Oxide Semiconductor r) is preferable. Also, as oxide 530, In-Ga oxide, In-Zn Oxides may also be used. CAAC-OS and CAC-OS will be described later. If you want to increase the on-current of the transistor 12, replace oxide 530 with In-Zn oxide It is preferable to use the following. When using In-Zn oxide for oxide 530, for example, oxide In-Zn oxide is used for 530a, and In-M- A layered structure using Zn oxide, or using In-M-Zn oxide for oxide 530a, A laminated structure using either oxide 530b or oxide 530c as In-Zn oxide. Examples include construction.

[0138] Furthermore, it is preferable to use a metal oxide with a low carrier concentration for the transistor 12. When reducing the carrier concentration of the metal oxide, the impurity concentration 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 particle density is referred to as high-purity intrinsic or substantially high-purity intrinsic. Examples of pure substances include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, Silicone is one example.

[0139] In particular, the hydrogen contained in metal oxides reacts with the oxygen bonded to the metal atoms to form water. In some cases, oxygen vacancies may form in metal oxides. Also, water can form oxygen vacancies in oxide 530. When an element is present, the oxygen deficiency and hydrogen combine to form V O It may form H. O H is Donna It functions as a metal, and electrons, which are carriers, can be generated. Also, some of the hydrogen is metallic. It can combine with oxygen atoms to generate electrons, which act as carriers. Transistors using metal oxides with a high hydrogen content exhibit normally-on characteristics. It is easy to move. Also, hydrogen in metal oxides is easily moved by stress such as heat and electric fields. Furthermore, if metal oxides contain a large amount of hydrogen, the reliability of transistors may deteriorate. In one embodiment of the present invention, V in oxide 530 O Reduce H as much as possible, high purity genuine or It is preferable to make it substantially high-purity intrinsic. Thus, V O Metals with sufficiently reduced H To obtain oxides, impurities such as water and hydrogen must be removed from the metal oxide (dehydration, dehydrogenation). This is sometimes referred to as chemical treatment.) This involves supplying oxygen to the metal oxide to compensate for oxygen deficiencies. (Sometimes referred to as oxygenation treatment.) is important. V O Impurities such as H are sufficiently low By using the reduced metal oxide in the channel formation region of the transistor, stable electrical properties can be achieved. It is possible to assign gender to it.

[0140] Defects where hydrogen is present in an oxygen vacancy can function as donors for metal oxides. However, Therefore, it is difficult to quantitatively evaluate the defect. In metal oxides, - In some cases, evaluation is based on carrier concentration rather than concentration. Therefore, in this specification, etc., metal The parameter for the oxide is not the donor concentration, but rather the value assuming a state where no electric field is applied. Carrier concentration may be used. In other words, the "carrier concentration" described in this specification, etc., is "d It can sometimes be rephrased as "ener concentration."

[0141] Therefore, when using metal oxides in oxide 530, the amount of hydrogen in the metal oxide should be kept as low as possible. It is preferable that the amount is reduced. Specifically, in metal oxides, secondary ion mass spectrometry (SIMS: Secondary Ion Mass Spectrometry) The hydrogen concentration obtained is 1 × 10⁻⁶ 20 atoms / cm 3 Less than 1 × 10 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 Less than, further Preferably 1 × 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.

[0142] Furthermore, when a metal oxide is used for oxide 530, the channel formation region of the metal oxide The rear concentration is 1 x 10 18 cm -3 The following is preferable: 1 × 10 17 cm -3 Not yet It is more preferable that it be full, 1 × 10 16 cm -3 It is even more preferable that it be less than, 1 x 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 concentration of the metal oxide in the channel-forming region There are no particular limitations regarding this, but for example, 1 x 10 -9 cm -3 It can be done this way.

[0143] 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.

[0144] 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 oxide A different layer may be formed between material 530b and the conductor 542. This different layer is more oxygen-rich than the conductor 542. Because it contains a large amount of, the heterogeneous layer is presumed to have insulating properties. At this time, the conductor 542 and, 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 as MIS (Metal-Insulator-Semiconduct It is sometimes referred to as an or structure, or a diode junction structure mainly consisting of an MIS structure.

[0145] Furthermore, the above-mentioned heterogeneous layer is not limited to being formed between the conductor 542 and the oxide 530b. For example, a different layer may be formed between the conductor 542 and the oxide 530c. This is between the conductor 542 and the oxide 530b, and between the conductor 542 and the oxide 530c. It may form.

[0146] Furthermore, the metal oxide that functions as a channel-forming region in oxide 530 is bandg It is preferable to use a cap with a voltage of 2 eV or more, preferably 2.5 eV or more. By using metal oxides with a large band gap, the off-current of the transistor can be reduced. It can be reduced.

[0147] Oxide 530 has oxide 530a beneath oxide 530b, so oxide 530a This suppresses the diffusion of impurities from structures formed below to oxide 530b. This is possible. Also, by having oxide 530c on oxide 530b, oxide 530 The diffusion of impurities from the structure formed above c to oxide 530b is suppressed. It is possible.

[0148] Furthermore, oxide 530 has a layered structure of multiple oxide layers with different atomic ratios of each metal atom. It is preferable to do so. Specifically, in the metal oxide used in oxide 530a, the constituent elements The atomic ratio of element M in the elementary oxide is the ratio of constituent elements in the metal oxide used in oxide 530b. It is preferable that the atomic ratio is greater than that 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 the case of oxide 530a or oxide 530b. You can use it.

[0149] Specifically, for oxide 530a, In:Ga:Zn = 1:3:4 [atomic ratio], Alternatively, a metal oxide in an atomic ratio of 1:1:0.5 may be used. Also, oxide 530b and Then, gold in an atomic ratio of In:Ga:Zn = 4:2:3 or 1:1:1. A group oxide can be used. Also, for oxide 530c, In:Ga:Zn = 1:3:4 [Atomic ratio], Ga:Zn=2:1 [Atomic ratio], or Ga:Zn=2:5 [Atomic ratio] You can use the metal oxide of ]. Also, a specific example of when oxide 530c is used in a layered structure and For example, In:Ga:Zn=4:2:3 [atomic ratio] and In:Ga:Zn=1:3:4 Layered structures with [atomic ratio] Ga:Zn=2:1 [atomic ratio] and In:Ga:Zn=4 Stacked structure with :2:3 [atomic ratio], Ga:Zn=2:5 [atomic ratio], and In:Ga: Layered structure of Zn=4:2:3 [atomic ratio], gallium oxide, and In:Ga:Zn=4: Examples include layered structures with an atomic ratio of 2:3.

[0150] 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 oxide 530a and oxide 530c is smaller than the electron affinity of oxide 530b. This is preferable.

[0151] 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 changes or becomes a continuous bond. In order to do this, oxide 530 At the interface between a and oxide 530b, and at the interface between oxide 530b and oxide 530c, the shape It is desirable to lower the defect level density of the resulting mixed layer.

[0152] Specifically, oxide 530a and oxide 530b, and oxide 530b and oxide 530c However, by having a common element other than oxygen (as the main component), the mixed layer has a low defect level density. It is possible to form an acid. For example, if oxide 530b is an In-Ga-Zn oxide, As the oxide 530a and oxide 530c, In-Ga-Zn oxide, Ga-Zn oxide, Gallium oxide or similar materials are recommended.

[0153] In this case, the main carrier pathway is oxide 530b. Oxide 530a, and oxidation By configuring material 530c as described above, the interface between oxide 530a and oxide 530b, and The defect level density at the interface between oxide 530b and oxide 530c can be reduced. Therefore, the influence of interfacial scattering on carrier conduction is reduced, and transistor 12 is high An ionic current can be obtained.

[0154] Furthermore, the 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, layers that function as semiconductors It is preferable to use such a material as a semiconductor material.

[0155] Here, in this specification, etc., "layered material" is a general term for a group of materials having a layered crystalline structure. Yes, it exists. Layered crystal structures are formed by layers created by covalent or ionic bonds, such as van der Wa. It is a structure in which layers are attached via weaker bonds than covalent or ionic bonds, such as the Ruhls force. Layered materials have high electrical conductivity within a single layer, meaning they have high two-dimensional electrical conductivity. A material that functions as a semiconductor and has high two-dimensional electrical conductivity is used in the channel formation region. This makes it possible to provide transistors with a large on-current.

[0156] Examples of 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 chalcogenides include transition metal chalcogenides and group 13 chalcogenides. .

[0157] For example, a transition metal chalcogenide that functions as a semiconductor can be used as oxide 530. Preferably, a transition metal chalcogenide applicable as oxide 530 is specified. These include molybdenum sulfide (typically MoS2) and molybdenum selenide (typically MoS2) e2), molybdenum tellurium (typically MoTe2), tungsten sulfide (typically W S2), tungsten selenide (typically WSe2), tungsten tellurium (typically (WTe2), hafnium sulfide (typically HfS2), hafnium selenide (typically (HfSe2), zirconium sulfide (typically ZrS2), zirconium selenide (alternative) Examples include ZrSe2).

[0158] On the oxide 530b, there is a conductor 542a that functions as a source electrode and a drain electrode. , and a conductor 542b are provided. The conductors 542a and 542b are, Aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum, tar ngsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium Choose from beryllium, indium, ruthenium, iridium, strontium, and lanthanum. The identified metal element, or an alloy containing the above-mentioned metal element, or a combination of the above-mentioned metal elements It is preferable to use a blended alloy, such as tantalum nitride, titanium nitride, or tungsten. Titanium nitrides containing titanium and aluminum, tantalum nitrides containing tantalum and aluminum, oxides Thenium, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel It is preferable to use oxides containing Kel. Also, tantalum nitride, titanium nitride, and 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 after absorbing oxygen. Therefore, it is preferable. Furthermore, metal nitride films such as tantalum nitride have barrier properties against hydrogen or oxygen. This is preferable because it has the following advantages.

[0159] Furthermore, although conductors 542a and 542b are shown as single-layer structures in Figure 17, A laminated structure of two or more layers is also possible. For example, a tantalum nitride film and a tungsten film may be laminated. This is good. Alternatively, a titanium film and an aluminum film may be laminated. Also, on a tungsten film A two-layer structure with stacked aluminum films, and a copper film on top of a copper-magnesium-aluminum alloy film. Laminated two-layer structure, two-layer structure with copper film laminated on titanium film, copper film laminated on tungsten film It may also be a two-layered structure.

[0160] Furthermore, a titanium film or titanium nitride film, and aluminum layered on top of the titanium film or titanium nitride film. A three-layer structure consisting of a laminated titanium film or copper film, with a titanium film or titanium nitride film formed on top of it. A molybdenum film or molybdenum nitride film, and on the molybdenum film or molybdenum nitride film An aluminum film or copper film is laminated on top of it, and then a molybdenum film or molybdenum nitride film is placed on top of that. There are three-layer structures that form a film. Furthermore, there are permeable films containing indium oxide, tin oxide, or zinc oxide. A brightly conductive material may be used.

[0161] Furthermore, as shown in Figure 17A, the oxide 530 has conductor 542a (conductor 542b) and Regions 543a and 543b are formed as low-resistance regions at and near the interface. In some cases, 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.

[0162] By providing the conductor 542a (conductor 542b) in contact with the oxide 530, The oxygen concentration in region 543a (region 543b) may decrease. Also, region 543a ( In region 543b), the metal contained in conductor 542a (conductor 542b) and oxide 530 A metal compound layer containing the component may be formed. In such cases, region 543a (region The carrier concentration in region 543b) increases, and region 543a (region 543b) becomes a low-resistance region. Yes.

[0163] The insulator 544 is provided so as to cover the conductors 542a and 542b, and the conductor The oxidation of 542a and conductor 542b is suppressed. At this time, the insulator 544 is oxide 5 It may be provided to cover the side of 30 and to be in contact with the insulator 524.

[0164] Insulator 544 includes hafnium, aluminum, gallium, yttrium, and zirconium. Umium, tungsten, titanium, tantalum, nickel, germanium, neodymium, lanthanum This involves using a metal oxide containing one or more metals selected from magnesium, etc. Yes, it is possible. Furthermore, silicon nitride or silicon nitride, etc., can also be used as the insulator 544. It is possible.

[0165] In particular, as the insulator 544, an oxide of either aluminum or hafnium, or both. The insulators include aluminum oxide, hafnium oxide, or aluminum and hafnium It is preferable to use an oxide containing um (hafnium aluminate), etc. In particular, hafnium Mualuminate has higher heat resistance than hafnium oxide film. Therefore, in subsequent heat treatment processes... In principle, it is preferable because it is less likely to crystallize. Note that conductor 542a and conductor 542b If the material is oxidation-resistant, or if its conductivity does not significantly decrease even when it absorbs oxygen, then it is an insulator. The 544 is not a mandatory component. The design should be tailored to the desired transistor characteristics.

[0166] The presence of the insulator 544 allows water and other impurities such as hydrogen contained in the insulator 580 to act as an acid. The diffusion of oxide 530b via oxide 530c and insulator 550 is suppressed. Yes, it is possible. In addition, the excess oxygen in the insulator 580 suppresses the oxidation of the conductor 560. It can be controlled.

[0167] The insulator 550 functions as the first gate insulating film. The insulator 550 is made of oxide 530 It is preferable to position it so as to be in contact with the inside (top and side) of c. The insulator 550 is Similar to the insulator 524 described above, it contains an excess of oxygen and releases oxygen upon heating. It is preferable to form it using a rim body.

[0168] Specifically, silicon oxide, silicon oxide nitride, silicon nitride oxide, silicon oxide containing excess oxygen silicon nitride, silicon oxide with added fluorine, silicon oxide with added carbon, carbon, and Silicon oxide with added nitrogen and silicon oxide with voids can be used. Silicon oxide and silicon oxide-nitride are preferred because they are stable to heat.

[0169] An insulator that releases oxygen upon heating is brought into contact with the upper surface of oxide 530c as insulator 550. By providing this, the oxide 530c allows the oxide 530b to pass from the insulator 550 to the oxide 530b. Oxygen can be effectively supplied to the channel-forming region. Also, similar to insulator 524, It is preferable that the concentration of impurities such as water or hydrogen in the insulator 550 is reduced. The film thickness of 50 is preferably between 1 nm and 20 nm.

[0170] 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 have a function that suppresses oxygen diffusion from 550 to the conductor 560. By providing a metal oxide that has the function of suppressing dispersion, the insulator 550 becomes a conductor 560. The diffusion of excess oxygen is suppressed. In other words, the reduction in the amount of excess oxygen supplied to oxide 530 is suppressed. It can be controlled. Furthermore, it can suppress the oxidation of the conductor 560 due to excess oxygen. As the metal oxide in question, any material suitable for use in insulator 544 may be used.

[0171] Furthermore, the insulator 550 may have a multilayer structure, similar to the second gate insulating film. As DISTRAs become smaller and more highly integrated, the gate insulating film becomes thinner, leading to leakage current and other issues. Problems may occur. For this reason, the insulator that functions as a gate insulating film is high- By creating a laminated structure of material k and a thermally stable material, the physical film thickness can be maintained. This makes it possible to reduce the gate potential during transistor operation. Furthermore, it is thermally stable and has a relative strength. A laminated structure with a high dielectric constant can be created.

[0172] The conductor 560, which functions as the first gate electrode, has a two-layer structure in Figures 17A and 17B. As shown, it may be a single-layer structure or a laminated structure of three or more layers.

[0173] Conductor 560a contains hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and nitrogen oxide molecules. A conductive material that has the function of suppressing the diffusion of impurities such as N2O, NO, NO2, and copper atoms. It is preferable to use an oxygen agent. Alternatively, oxygen (for example, at least one oxygen atom, oxygen molecule, etc.) It is preferable to use a conductive material that has the function of suppressing the diffusion of ) conductor 560a By having the function of suppressing the diffusion of oxygen, the oxygen contained in the insulator 550 causes the conductor 5 This can suppress the oxidation of 60b, which reduces its conductivity. It also suppresses the diffusion of oxygen. Examples of functional conductive materials include tantalum, tantalum nitride, ruthenium, or It is preferable to use ruthenium oxide or the like. Also, as the conductor 560a, oxide 530 An oxide semiconductor applicable to this can be used. In that case, the conductor 560b is sputtered. By depositing a film using the ring method, the electrical resistance of the conductor 560a is reduced, making it a conductor. This can be done. This can be called an OC (Oxide Conductor) electrode.

[0174] 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 mainly composed of um can be used. In addition, the conductor 560b has a laminated structure. This may also be done, for example, by forming a laminated structure of titanium or titanium nitride and the above-mentioned conductive material. .

[0175] The insulator 580 is provided on the conductors 542a and 542b via the insulator 544. It is possible. The insulator 580 preferably has an excess oxygen region. For example, insulator 58 As 0, silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, fluorine silicon oxide with added carbon, silicon oxide with added carbon, and silicon oxide with added nitrogen. It is preferable that the material contains silicon, porous silicon oxide, or resin, etc. In particular, oxidative silicon Silicon and silicon oxide nitride are preferred because they are thermally stable. In particular, silicon oxide Silicon oxide having pores and other structures can easily form an excess oxygen region in a later process. This is preferable because it allows for this.

[0176] The insulator 580 preferably has an excess oxygen region. Oxygen is released upon heating. The insulator 580 is provided such that it has a region in contact with the oxide 530c, The oxygen in 0 is efficiently converted to oxides 530a and 530b via oxide 530c. It can be supplied in a low volume. Furthermore, the concentration of impurities such as water or hydrogen in the insulator 580 is reduced. It is preferable that this is the case.

[0177] The opening in the insulator 580 is formed superimposed on the region between the conductor 542a and the conductor 542b. This allows the conductor 560 to pass through the opening of the insulator 580, and the conductor 542a and the conductor. It is formed so as to be embedded in the region sandwiched between 542b.

[0178] When miniaturizing semiconductor devices, it is necessary to shorten the gate length, but the conductor 5 It is necessary to prevent the conductivity of 60 from decreasing. To that end, the film thickness of conductor 560 is increased. As a result, the conductor 560 can have a shape with a high aspect ratio. In this embodiment, In order to embed the body 560 into the opening of the insulator 580, the conductor 560 is aspect ratio Even when forming a shape with a high ratio, the conductive material 560 is formed without collapsing during the process. It is possible.

[0179] 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 insulator 550 and the insulator 580. Oxygen can be supplied to the oxide 530 from the excess oxygen region.

[0180] For example, as insulator 574, hafnium, aluminum, gallium, yttrium, Zirconium, tungsten, titanium, tantalum, nickel, germanium, or magnesium A metal oxide containing one or more elements selected from elements such as cilium can be used.

[0181] In particular, aluminum oxide has high barrier properties and is suitable for 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 by this method serves as both an oxygen source and a barrier film against impurities such as hydrogen. It can also function as such.

[0182] Furthermore, it is preferable to provide an insulator 581 that functions as an interlayer film on top of the insulator 574. i. Insulator 581, like insulator 524, reduces the concentration of impurities such as water or hydrogen in the film. It is preferable that this be done.

[0183] Furthermore, openings formed in insulators 581, 574, 580, and 544 Conductors 540a and 540b are placed in the opening. 0b is provided opposite the conductor 560. Conductors 540a and 540b are, The configuration is the same as that of conductors 546 and 548, which will be described later.

[0184] An insulator 582 is provided on the insulator 581. The insulator 582 is designed to absorb oxygen and hydrogen. In contrast, it is preferable to use a barrier material. Therefore, the insulator 582 is an insulating material. The same material as the edge 514 can be used. For example, aluminum oxide can be used for the insulator 582. It is preferable to use metal oxides such as nium, hafnium oxide, and tantalum oxide.

[0185] 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 moisture and other impurities from passing through the film. Therefore, oxidation Aluminum is subject to impurities such as hydrogen and water during and after the transistor manufacturing process. This prevents contamination of transistor 12. This can suppress the release of oxygen from the oxide. Therefore, for transistor 12 It is suitable for use as a protective film.

[0186] Furthermore, an insulator 586 is provided on the insulator 582. The insulator 586 is an insulator Similar materials to 320 can be used. In addition, these insulators have a relatively low dielectric constant. By applying a suitable material, parasitic capacitance between wires can be reduced. For example, As the edge 586, a silicon oxide film or a silicon oxide-nitride film can be used.

[0187] Also, insulator 520, insulator 522, insulator 524, insulator 544, insulator 580, The edge 574, insulator 581, insulator 582, and insulator 586 contain a conductor 546, and Conductors such as 548 are embedded within.

[0188] Conductors 546 and 548 are connected to capacitor 14, transistor 12, or transistor It functions as a plug or wiring to connect to Zista 13. Conductor 546, and conductive Body 548 can be provided using the same material as the conductor 328 or the conductor 330. .

[0189] Furthermore, after the formation of the transistor 12, an opening is formed to surround the transistor 12. An insulator with high barrier properties against hydrogen or water may be formed to cover the opening. By encasing the transistor 12 in a highly barrier insulator, moisture and hydrogen are prevented from entering from the outside. This can prevent water from entering. Alternatively, multiple transistors 12 can be grouped together to prevent water from entering. It may be wrapped in an insulating material with high barrier properties against water or other materials. Note that transistor 12 When forming an opening to surround the insulator, for example, an opening that reaches the insulator 514 or the insulator 522. Forming a barrier, the above-mentioned highly barrier insulator is brought into contact with the insulator 514 or the insulator 522. Forming it is preferable because it can also serve as part of the manufacturing process for transistor 12. Examples of insulators with high barrier properties against elements or water include materials similar to insulator 522. You can use it.

[0190] Next, a capacitor 14 is provided above the transistor 12. 14 has a conductor 610, a conductor 620, and an insulator 630.

[0191] Furthermore, a conductor 612 may be provided on the conductor 546 and the conductor 548. Conductor 6 12 functions as a plug or wire for connecting to transistor 12. Conductor 6 10 functions as an electrode of the capacitor 14. Note that the conductor 612 and the conductor 610 can be formed simultaneously.

[0192] Conductors 612 and 610 contain molybdenum, titanium, tantalum, and tungsten. A metal film containing elements selected from aluminum, copper, chromium, neodymium, and scandium. or metal nitride films containing the above-mentioned elements (tantalum nitride film, titanium nitride film, molybdenum nitride film) Butene film, tungsten nitride film, etc. can be used. Alternatively, indium tin oxide, Indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide Indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium By applying conductive materials such as zinc oxide and indium tin oxide with added silicon dioxide, It can also be done this way.

[0193] In Figure 15, the conductors 612 and 610 are shown as having a single-layer structure, but the configuration is not limited to this. It is not limited to a single layer, and a laminated structure of two or more layers is also acceptable. For example, a conductor with barrier properties and a highly conductive material. A conductor with barrier properties between it and the conductor, and a conductor with high conductivity that has high adhesion to the conductor. A conductive material may be formed.

[0194] The conductor 620 is provided so as to be superimposed on the conductor 610 via the insulator 630. The conductor 620 uses a conductive material such as a metal material, an alloy material, or a metal oxide material. This is possible. High-melting-point materials such as tungsten and molybdenum, which offer both heat resistance and conductivity, are used. It is preferable to use tungsten, and it is particularly preferable to use other structures such as conductors. When forming at the same time, low-resistance metal materials such as Cu (copper) and Al (aluminum) are used. Use it.

[0195] An insulator 640 is provided on the conductor 620 and the insulator 630. 0 can be provided using the same material as insulator 320. Also, insulator 640 is It may also function as a flattening film that covers the uneven surface below it.

[0196] By using this structure, semiconductor devices using transistors having oxide semiconductors This allows for miniaturization or high integration.

[0197] Figures 18A and 18B show modified versions of transistor 12 shown in Figures 17A and 17B. Figure 17A is a cross-sectional view of transistor 12 in the channel length direction, and Figure 17B is a transistor This is a cross-sectional view of channel 12 in the channel width direction. Note that the configuration shown in Figures 18A and 18B is a transistor This invention can also be applied to other transistors in semiconductor devices according to one aspect of the present invention, such as ZISTA 13. It is possible.

[0198] Figure 18A is a cross-sectional view of transistor 12 in the channel length direction, and Figure 18B is a cross-sectional view of transistor 12. This is a cross-sectional view of transistor 12 in the channel width direction. Transistor 1 shown in Figures 18A and 18B. 2 has insulators 402 and 404, which is the transition shown in Figures 17A and 17B. It is different from sta 12. Also, an insulator 552 is provided in contact with the side surface of the conductor 540a, and the conductive The insulator 552 is provided in contact with the side surface of body 540b, as shown in Figures 17A and 17B. It differs from the transistor 12. Furthermore, it does not have an insulator 520, as shown in Figures 17A and 17B. This is different from the transistor 12 shown.

[0199] The transistor 12 shown in Figures 18A and 18B has an insulator 402 provided on an insulator 512. Furthermore, an insulator 404 is provided on the insulator 574 and on the insulator 402.

[0200] In the transistor 12 shown in Figures 18A and 18B, insulator 514, insulator 516, insulation Body 522, insulator 524, insulator 544, insulator 580, and insulator 574 are patterned It is constructed so that the insulator 404 covers them. In other words, the insulator 404 is , the top surface of insulator 574, the side surface of insulator 574, the side surface of insulator 580, the side surface of insulator 544 , side of insulator 524, side of insulator 522, side of insulator 516, side of insulator 514 , and they come into contact with the upper surface of the insulator 402. As a result, the oxide 530 etc. comes into contact with the insulator 404 It is isolated from the outside by the insulator 402.

[0201] Insulators 402 and 404 contain hydrogen (for example, hydrogen atoms, hydrogen molecules, etc.) It is preferable that the insulator 402 and have a high function of suppressing the diffusion of water molecules. As the insulator 404, a material with high hydrogen barrier properties is silicon nitride or silicon nitride oxide. It is preferable to use a condenser. This suppresses the diffusion of hydrogen and other elements into oxide 530. This allows us to suppress the deterioration of the characteristics of transistor 12. Therefore, the reliability of a semiconductor device according to one embodiment of the present invention can be improved.

[0202] Insulator 552 is insulator 581, insulator 404, insulator 574, insulator 580, and insulator It is provided in contact with the edge 544. The insulator 552 has the function of suppressing the diffusion of hydrogen or water molecules. It is preferable to have the following. For example, as the insulator 552, a material with high hydrogen barrier properties is Insulators such as silicon nitride, aluminum oxide, or silicon nitride oxide can be used. Preferred. In particular, since silicon nitride is a material with high hydrogen barrier properties, it is used as an insulator 552. It is preferable to use it in this way. By using a material with high hydrogen barrier properties as the insulator 552, Impurities such as water or hydrogen pass through the insulator 580, etc., to the conductors 540a and 540b. This suppresses diffusion into the oxide 530. Also, it is contained in the insulator 580. This makes it possible to suppress the absorption of oxygen by the conductors 540a and 540b. As described above, the reliability of a semiconductor device according to one aspect of the present invention can be improved.

[0203] Figure 19 shows the configuration of transistors 12 and 13 as shown in Figures 18A and 18B. This is a cross-sectional view showing an example of the configuration of a semiconductor device in the case of [the above]. On the side surface of the conductor 546, A rim 552 is provided.

[0204] This embodiment can be implemented in appropriate combination with the configurations described in other embodiments, etc. It is possible.

[0205] (Embodiment 3) In this embodiment, it can be used in the OS transistor described in the above embodiment. The composition of the metal oxides CAC-OS and CAAC-OS will be described. In this specification, CAC represents an example of a function or material composition, and CAAC represents a crystal structure. This is an example.

[0206] <Composition of metal oxides> CAC-OS or CAC-metal oxide refers to materials that have a conductive function 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 active layer of the transistor. When used, the conductive function is the function of allowing electrons (or holes) that act as carriers to flow, and is an insulating material. The function of a material is to prevent the flow of electrons, which act as carriers. This is the function of both conductivity and insulation. By making the two functions work complementaryly, it enables a switching function (On / Off). This function can be imparted to CAC-OS or CAC-metal oxide. In CAC-OS or CAC-metal oxide, the respective functions are separated. By doing so, the functions of both can be maximized.

[0207] 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.

[0208] 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.

[0209] Furthermore, CAC-OS or CAC-metal oxide have different band gaps. It is composed of the following components. For example, CAC-OS or CAC-metal oxid e consists of a component with a wide gap due to the insulating region and a narrow gap due to the conductive region. - It consists of a component having a gap. In this configuration, when the carrier is flowed, In components with a narrow gap, mainly carriers flow. Also, the narrow gap The components possessed act complementaryly with components having a wide gap, and have a narrow gap. Carriers also flow to components with a wide gap in conjunction with the components. Therefore, the above CA C-OS or CAC-metal oxide is used in the channel formation region of the transistor. In this case, the transistor has a high current driving force in the ON state, that is, a large ON current, and High field-effect mobility can be obtained.

[0210] In other words, CAC-OS or CAC-metal oxide is a matrix composite material. (matrix composite), or metal matrix composite (metal m It can also be called an atrix composite.

[0211] <Structure of metal oxides> Oxide semiconductors are divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include CAAC-OS and polycrystalline oxide semiconductors. , nc-OS(nanocrystalline oxide semiconductor or), pseudo-amorphous oxide semiconductor (a-like OS: amorphous-like) Examples include oxide semiconductors and amorphous oxide semiconductors.

[0212] CAAC-OS has c-axis orientation and multiple nanocrystals are linked in the ab-plane direction. It has a crystalline structure that is linked and distorted. Note that distortion refers to the linkage between multiple nanocrystals. Within a region, between a region with a aligned grid arrangement and another region with a aligned grid arrangement, the grid arrangement This refers to the point where the orientation has changed.

[0213] Nanocrystals are based on a hexagonal shape, but they are not necessarily regular hexagons; they can also be non-regular hexagonal. There are also cases where the distortion has a grid arrangement of pentagons, heptagons, etc. Oh, in CAAC-OS, even near strain, there are clear grain boundaries. It is not possible to confirm the grain boundaries (also known as Lie). In other words, due to the distortion of the lattice arrangement, the grain boundaries It can be seen that the formation is suppressed. This is because CAAC-OS is suppressed in the ab plane direction. The arrangement of oxygen atoms is not dense, and the substitution of metal elements changes the bond distance between atoms. This is thought to be because distortion can be tolerated by doing so.

[0214] 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 layered structure). Note that indium and element M are mutually substituted. It is possible, and if element M in the (M,Zn) layer is replaced with indium, the (In,M,Zn) layer It can also be expressed as follows. Furthermore, if the indium in the In layer is substituted with element M, then (In,M) It can also be described as a layer.

[0215] CAAC-OS is a highly crystalline oxide semiconductor. On the other hand, CAAC-OS has a clear Since grain boundaries cannot be identified, a decrease in electron mobility caused by grain boundaries occurs. It can be said that it is difficult. Also, 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 semiconductor with few impurities or defects (such as oxygen deficiencies). It can also be called a conductor. Therefore, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat-resistant and highly reliable. Furthermore, CAAC-OS is designed to withstand high temperatures (so-called 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.

[0216] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially regions larger than 1 nm). It has periodicity in the atomic arrangement in the region of 3 nm or less. Also, nc-OS has different na No regularity is observed in the crystal orientation between the crystals. Therefore, no orientation is observed throughout the entire film. Therefore, depending on the analytical method, nc-OS may be a-like OS or amorphous oxide semiconductor. It can sometimes be indistinguishable from the body.

[0217] a-like OS is an oxide having a structure between nc-OS and amorphous oxide semiconductors. It is a semiconductor. an a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS.

[0218] 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 n It may have two or more types of c-OS and CAAC-OS.

[0219] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0220] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility is obtained. This can be achieved. Furthermore, highly reliable transistors can be realized.

[0221] Furthermore, it is preferable to use an oxide semiconductor with a low carrier concentration for the transistor. When lowering the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film is reduced. The degree should be lowered, and the defect level density should be lowered. In this specification, the impurity concentration is low, A low defect level density is referred to as high-purity intrinsic or substantially high-purity intrinsic.

[0222] Furthermore, oxide semiconductor films that are high-purity intrinsic or substantially high-purity intrinsic have a low defect level density. Therefore, the trap level density may also be low.

[0223] Furthermore, the time required for charges trapped in the trap levels of an oxide semiconductor to disappear is... It can behave for a long time, almost like a fixed charge. Therefore, the trap level density is high. Transistors in which a channel formation region is formed in an oxide semiconductor have unstable electrical properties. There are cases where this occurs.

[0224] Therefore, in order to stabilize the electrical characteristics of a transistor, impurities in oxide semiconductors must be removed. Reducing the concentration is effective. Also, to reduce the impurity concentration in oxide semiconductors It is preferable to also reduce the concentration of impurities in the adjacent membrane. Examples of impurities include hydrogen and nitrogen. These include alkali metals, alkaline earth metals, iron, nickel, silicon, etc.

[0225] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0226] In oxide semiconductors, if silicon or carbon, which are among the Group 14 elements, are present, oxidation occurs. Defect levels are formed in silicon semiconductors. Therefore, in oxide semiconductors, silicon and carbon The concentration of the element and the concentrations of silicon and carbon near the interface with the oxide semiconductor (secondary ion mass spectrometry) (SIMS: Secondary Ion Mass Spectrometry) The concentration obtained is 2 × 10 18 atoms / cm 3 The following is preferably 2 × 10 17 a toms / cm 3 The following applies:

[0227] 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, alkali metals or aluminum in oxide semiconductors obtained by SIMS. The concentration of potassium earth metals is 1 × 10⁻⁶ 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0228] Furthermore, in oxide semiconductors, when nitrogen is present, electrons, which are carriers, are generated. As the nitrogen concentration increases, it becomes easier to convert to n-type semiconductors. As a result, oxide semiconductors containing nitrogen become semiconductors. The transistor used tends to exhibit normally-on characteristics. Therefore, the oxide semiconductor In this context, it is preferable that nitrogen is reduced as much as possible, for example, in oxide semiconductors. The nitrogen concentration in SIMS is 5 × 10⁻⁶. 19 atoms / cm 3 Less than 5x 10 18 atoms / cm 3 More preferably 1 × 10 18 atoms / cm 3 below More preferably 5 × 10 17 atoms / cm 3 The following applies:

[0229] Furthermore, the hydrogen contained in oxide semiconductors reacts with the oxygen bonded to the metal atoms to form water. Therefore, an oxygen deficiency may form. When hydrogen enters this oxygen deficiency, the carrier electrons In some cases, a child may be produced. Also, some of the hydrogen combines with the metal atom and oxygen, resulting in a crystal. It can generate electrons, which are carriers. Therefore, oxide semiconductors containing hydrogen. Transistors using this material tend to exhibit normally-on characteristics. Therefore, in oxide semiconductors It is preferable that hydrogen content be reduced as much as possible. Specifically, in oxide semiconductors, The hydrogen concentration obtained by SIMS is 1 × 10⁻⁶ 20 atoms / cm 3 Less than, preferably 1 x 10 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 Less than 1 × 10 18 atoms / cm 3 Less than.

[0230] Using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor. This allows for the provision of stable electrical characteristics.

[0231] This embodiment can be implemented in appropriate combination with the configurations described in other embodiments, etc. It is possible.

[0232] (Embodiment 4) This embodiment describes a storage device using the semiconductor device 10 described in Embodiment 1. I will reveal it.

[0233] <Storage device> Figure 20 is a block diagram showing an example of a storage device configuration. The storage device 30 is connected to the peripheral circuit 31. , and a cell array 51. Peripheral circuit 31 includes a low decoder 32, a word line dry Circuit 33, bit line driver circuit 34, output circuit 35, control logic circuit 36 It has.

[0234] The word line driver circuit 33 has the function of supplying potential to the wiring WL. The IBA circuit 34 includes a column decoder 41, a precharge circuit 42, an amplification circuit 43, and a writing circuit. It has a power supply circuit 44. The precharge circuit 42 is a device that precharges wiring RL, etc. It has the ability. The amplification circuit 43 has the function of amplifying the data signal read from wiring RL. The wiring WWL, RWL, SL, BL, and RL are as described above. As described in the first embodiment of the method, the semiconductor that functions as a memory cell in the cell array 51 This is the wiring connected to device 10. The amplified data signal is transmitted via output circuit 35. The data signal RDATA is then output to the outside of the storage device 30.

[0235] The storage device 30 receives a low power supply voltage (VSS) from an external source as the power supply voltage, and the peripheral circuit 31 A high power supply voltage (VDD) and a high power supply voltage (VIL) for the cell array 51 are supplied.

[0236] Furthermore, the storage device 30 contains control signals (CE, WE, RE), address signals ADDR, and The data signal WDATA is input from an external source. The address signal ADDR is input to the low decoder 32 The WDATA is input to the column decoder 41 and then to the writing circuit 44.

[0237] The control logic circuit 36 ​​processes the external input signals (CE, WE, RE). Then, control signals for the low decoder 32 and column decoder 41 are generated. CE is chip rice These are write signals, WE is the write enable signal, and RE is the read enable signal. This is a signal. The signals processed by the control logic circuit 36 ​​are not limited to this. Instead, you can input other control signals as needed.

[0238] Furthermore, the aforementioned circuits and signals can be selected or omitted as needed.

[0239] OS transistors can be applied to the transistors that make up the cell array 51. Furthermore, OS transistors can be applied to the transistors that make up the peripheral circuit 31. The cell array 51 and peripheral circuit 31 are formed using OS transistors, Ray 51 and peripheral circuit 31 can be manufactured using the same manufacturing process, reducing manufacturing costs. It can be kept low.

[0240] [Example of cell array configuration] Figure 21 shows the details of the cell array 51. The cell array 51 has m cells in each row (where m is 1 or greater). It is an integer. ) items, n (n is an integer greater than or equal to 1) items per row, for a total of m × n memory cells. The semiconductor device 10 functions as a module, and the semiconductor device 10 is shown in Figures 10, 12, and 1 As illustrated in 4, they are arranged in a matrix. In Figure 21, the address of semiconductor device 10 The following are also included in the notation: [1,1], [m,1], [i,j], [1,n], [m,n] At the address where (i is an integer between 1 and m, and j is an integer between 1 and n, from 1 to n) The semiconductor device 10 is shown in its position. Note that the cell array 51 and word line driver are also shown. The number of wires connecting to circuit 33 is the configuration of semiconductor device 10, and the number of semiconductors included in one row. It is determined by the number of devices 10, etc. Also, the cell array 51 and the bit line driver circuit 34 The number of wires connecting them is the configuration of the semiconductor device 10, and the number of semiconductor device 10 included in one row. It is determined by factors such as the number.

[0241] By configuring the semiconductor device 10, data can be written by charging or discharging an electric charge. Because it allows for replacement and reading, it is possible to write and read data virtually an unlimited number of times. Data can be read. When reading data, the held charge is discharged, Because data can be read without damaging the data, data refresh is not required. This reduces the power consumption associated with charging and discharging the electric charge.

[0242] Furthermore, by configuring the semiconductor device 10, the amount of charge required when writing back data can be reduced. Therefore, the retained charge can be discharged to wiring with a large capacitance without needing to be discharged. It can read data. It also offers excellent reliability for long-term data retention. It can be used as a conductive device.

[0243] (Embodiment 5) This embodiment is an electronic component and electrical device incorporating the storage device shown in the above embodiment. An example of a sub-device is shown.

[0244] <Electronic Components> First, an example of an electronic component incorporating the memory device 300 will be explained using Figures 22A and 22B. To perform a clearing.

[0245] Figure 22A shows the electronic component 700 and the circuit board (mounted circuit board 704) on which the electronic component 700 is mounted. A perspective view is shown. The electronic component 700 shown in Figure 22A is an IC chip, and has leads and circuitry. It has a part. The electronic component 700 is mounted on a printed circuit board 702, for example. Multiple C chips are combined and each is electrically connected on the printed circuit board 702. This completes the mounting board 704.

[0246] The electronic component 700 is provided with the storage device 30 shown in the above embodiment as the circuit section. Figure 22A shows that the package of electronic component 700 is QFP (Quad Flat Pack). The kage (framework) is applied, but the package configuration is not limited to this. The memory device is Si A layer 61 on which transistors are provided and a layer 62 on which OS transistors are provided are stacked. Yes, they are.

[0247] Figure 22B shows a perspective view of electronic component 730. Electronic component 730 is a SiP (System Integrity Packaging). An example of an in-package (or MCM - Multi-Chip Module) The electronic component 730 is an interposer on the package substrate 732 (printed circuit board). A 731 is provided, and a semiconductor device 735 and multiple storage devices are mounted on the interposer 731. 30 is provided.

[0248] In electronic component 730, the storage device 30 is a high-bandwidth memory (HBM). An example of its use as dth Memory is shown. Also, semiconductor device 735 has C PU (Central Processing Unit), GPU (Graphic Processing Unit), FPGA (Field Programmable Integrated circuits (semiconductor devices) such as gate arrays can be used.

[0249] The package substrate 732 is a ceramic substrate, a plastic substrate, or a glass epoxy substrate. A substrate can be used. The interposer 731 is a silicon interposer. Resin interposers and the like can be used.

[0250] The interposer 731 has multiple wirings and powers multiple integrated circuits with different terminal pitches. It has the function of connecting electrically. Multiple wires are provided in single layer or multi-layer configuration. Also, The interposer 731 packages the integrated circuit provided on the interposer 731 to the package substrate 7 It has the function of electrically connecting to the electrode provided at 32. Interposer is sometimes called a "redistribution board" or "intermediate board." Also, interposer 73 A through electrode is provided in 1, and the integrated circuit and the package substrate 732 are electrically connected using the through electrode. In some cases, it may be connected to a silicon interposer. Also, in silicon interposers, TSVs are used as through electrodes. It is also possible to use (through silicon vias).

[0251] It is preferable to use a silicon interposer as the interposer 731. Because interposers do not require active elements, they can be manufactured at a lower cost than integrated circuits. This is possible. On the other hand, the wiring of the silicon interposer is formed using a semiconductor process. Because this allows for the formation of fine wiring, which is difficult with resin interposers, it is easy.

[0252] In HBM, many wires need to be connected to achieve a wide memory bandwidth. Therefore, interposers that implement HBM require the formation of fine and high-density wiring. Therefore, a silicon interposer is used for the interposer that implements HBM. This is preferable.

[0253] Furthermore, in SiP and MCM using silicon interposers, integrated circuits and interposers are used. Reliability degradation due to differences in expansion coefficients between posers is less likely to occur. Also, silicon interpolation Because the silicon interposer has high surface flatness, integrated circuits and silicon are placed on the silicon interposer. Connection failures between interposers are less likely to occur. In particular, when multiple integrated circuits are placed on the interposer... In 2.5D packages (2.5-dimensional packaging) where components are arranged side by side, silicon interpolation It is preferable to use "za".

[0254] Alternatively, a heat sink (heat dissipation plate) may be provided in conjunction with the electronic component 730. If a configuration is provided, it is preferable to align the heights of the integrated circuits provided on the interposer 731. For example, in the electronic component 730 shown in this embodiment, the storage device 30 and the semiconductor device 735 It is preferable to make the heights the same.

[0255] To mount the electronic component 730 onto another substrate, an electrode 733 is placed at the bottom of the package substrate 732. It may be provided. Figure 22B shows an example in which electrode 733 is formed with solder balls. By arranging solder balls in a matrix pattern at the bottom of the package substrate 732, BGA (Bal This enables the implementation of a grid array. Furthermore, electrodes 733 are formed with conductive pins. This may be done by providing conductive pins in a matrix pattern on the bottom of the package substrate 732. This enables the implementation of PGA (Pin Grid Array).

[0256] The electronic component 730 can be mounted on other boards using various mounting methods, not limited to BGA and PGA. It can be installed. For example, SPGA (Staggered Pin Grid Ar ray), LGA (Land Grid Array), QFP (Quad Flat Package), QFJ(Quad Flat J-leaded package) , or QFN (Quad Flat Non-leaded package), etc. Implementation methods can be used.

[0257] <Electronic equipment> Next, an example of an electronic device equipped with the above-mentioned electronic components will be explained using Figure 23.

[0258] The robot 7100 includes an illuminance sensor, microphone, camera, speaker, and display. , various sensors (infrared sensors, ultrasonic sensors, acceleration sensors, piezoelectric sensors, optical sensors, It includes a gyro sensor, etc., and a movement mechanism, etc. Electronic component 730 is a processor, etc. It has the ability to control these peripheral devices. For example, the electronic component 700 is detected by a sensor. It has the function of storing acquired data.

[0259] The microphone has the function of detecting acoustic signals such as the user's voice and ambient sounds. Furthermore, the speaker has the function of emitting audio signals such as voice and warning sounds. The Bot 7100 analyzes the audio signal input via the microphone and performs the necessary actions. Audio signals can be emitted from the speaker. In robot 7100, It is possible to communicate with the user using an microphone and speaker. That is the case.

[0260] The camera has the function of imaging the area around robot 7100. It has the function of moving using a moving mechanism. Robot 7100 uses a camera to survey its surroundings. By capturing images and analyzing them, it is possible to detect the presence or absence of obstacles while moving. .

[0261] The aircraft 7120 has propellers, cameras, and batteries, and flies autonomously. It has a function. Electronic component 730 has the function of controlling these peripheral devices.

[0262] For example, image data captured by the camera is stored in electronic component 700. Electronic component 73 0 can analyze image data and detect the presence or absence of obstacles during movement. Furthermore, the remaining battery level is estimated from the change in the battery's storage capacity using electronic component 730. It is possible.

[0263] The 7140 cleaning robot has a display located on the top and multiple cameras located on the sides. It has a camera, brush, control buttons, various sensors, etc. Although not shown in the illustration, it is a cleaning robot. The To7140 is equipped with tires, a suction nozzle, etc. The cleaning robot 7140 is self-propelled. It can detect dust and suck it up through a suction port located on the bottom.

[0264] For example, electronic component 730 analyzes the image captured by the camera and identifies walls, furniture, steps, etc. It can determine the presence or absence of obstacles. Furthermore, image analysis can detect if wires or other objects are entangled in the brush. If an object that appears likely to be present is detected, the brush rotation can be stopped.

[0265] Automobile 7160 has an engine, tires, brakes, steering system, camera, etc. For example, electronic component 730 displays navigation information, speed, engine status, and gear selection status. Based on data such as brake usage frequency, the driving conditions of the vehicle 7160 are optimized. Control is performed for this purpose. For example, image data captured by the camera is stored in electronic component 700. .

[0266] Electronic component 700 and / or electronic component 730 are TV device 7200 (television receiver Image device), smartphone 7210, PC (personal computer) 7220, 723 It can be incorporated into game consoles such as the 7240 and 7260.

[0267] For example, the electronic component 730 built into the TV device 7200 functions as an image engine. For example, electronic component 730 can perform noise reduction and resolution upconversion. This involves image processing such as the following.

[0268] The Smartphone 7210 is an example of a mobile information terminal. The Smartphone 7210 is, It has a microphone, camera, speaker, various sensors, and display unit. Electronic component 73 These peripheral devices are controlled by the value 0.

[0269] PC7220 and PC7230 are examples of notebook PCs and desktop PCs, respectively. The C7230 includes a keyboard 7232 and a monitor device 7233, which can be connected wirelessly or via wired connection. It is connectable. Game console 7240 is an example of a portable game console. Game console 7260 is This is an example of a home console. The 7260 console has wireless or wired controllers. 7262 is connected. The controller 7262 is connected to the electronic components 700 and / or electric Sub-component 730 can also be incorporated.

[0270] This embodiment may be implemented in appropriate combination with the configurations described in other embodiments. This is possible.

[0271] (Notes regarding the descriptions in this specification, etc.) The above embodiments and a description of each component in those embodiments are provided below.

[0272] The configurations shown in each embodiment can be appropriately combined with the configurations shown in other embodiments or examples. This can be one embodiment of the present invention. Furthermore, multiple configurations can be included in one embodiment. When examples are provided, it is possible to combine the example configurations as appropriate.

[0273] Furthermore, the content described in one embodiment (even a part of it) may be subject to change in implementation. Other content (even partial content) described in form, and / or one or more other facts The content described in the form of implementation (even if only a part of it) may be applied, combined, or replaced. It is possible to perform tasks such as drawing.

[0274] Furthermore, the content described in each embodiment refers to the use of various figures in each embodiment. This refers to the content described or the content described using the text included in the specification.

[0275] Note that a diagram (even a part of it) described in one embodiment may be a part of that diagram. , other figures (even partial ones) described in the embodiment, and / or one or more In the diagram (or even just a part of it) described in another embodiment of the number, by combining them... This allows for the creation of even more diagrams.

[0276] Furthermore, in this specification, etc., block diagrams classify components according to their function and treat them as independent of each other. It is shown as a block. However, in actual circuits, the components are divided by function. It is difficult to separate the functions, and when multiple functions are involved in a single circuit, or when multiple circuits are involved... In some cases, one function may be involved. Therefore, the blocks in the block diagram are specified in the specification. The components described are not limited to those explained, and can be appropriately rephrased depending on the situation.

[0277] Furthermore, in the drawings, the size, layer thickness, or area are shown at arbitrary sizes for the sake of explanation. Therefore, it is not necessarily limited to that scale. Furthermore, the drawings are made with clarity in mind. This is a schematic representation and is not limited to the shapes or values ​​shown in the drawings. For example... , variations in signals, voltages, or currents due to noise, or signals due to timing discrepancies This can include variations in voltage, current, and other parameters.

[0278] Furthermore, the positional relationships of the components shown in drawings are relative. Therefore, drawings When referring to and explaining the components, terms such as "above" and "below" that indicate positional relationships are for convenience. It may be used in this way. The positional relationship of the components is not limited to what is described herein, and may vary. It can be rephrased appropriately depending on the situation.

[0279] In this specification, when describing the connection relationships of transistors, the term "source or drain" is used. One side (or first electrode, or first terminal), the other side of source and drain is "source or drain The notation "the other side of the input" (or second electrode, or second terminal) is used. The source and drain of a transistor vary depending on its structure or operating conditions. Regarding the terminology for the source and drain of a transistor, please refer to the source (drain) terminals, The term can be appropriately rephrased depending on the context, such as "source (drain) electrode," etc.

[0280] 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. Furthermore, the terms "electrode" and "wiring" can refer to multiple "electrodes" and This includes cases where the wiring is formed as an integrated unit.

[0281] Furthermore, in this specification, voltage and potential may be used interchangeably as appropriate. Voltage is a base This refers to the potential difference from a reference potential. For example, the reference potential is the ground voltage (earth). If we consider voltage as a unit of measurement, then voltage can be rephrased as potential. Ground potential is not necessarily 0V. This does not necessarily mean that. Furthermore, electric potential is relative, and depending on the reference potential, This may change the potential supplied to wiring, etc.

[0282] Furthermore, in this specification, a node is defined as having terminals and wiring, depending on the circuit configuration and device structure. These can be rephrased as electrodes, conductive layers, conductors, impurity regions, etc. Also, terminals, distribution Lines and other elements can be rephrased as nodes.

[0283] In this specification, etc., "A and B are connected" means that A and B are electrically connected. This refers to things that are electrically connected. Here, A and B are said to be electrically connected to each other. The object (a switch, transistor element, or diode or other element, or said element and A connection (referring to a circuit including wiring, etc.) that allows electrical signals to be transmitted between A and B is possible when such a connection exists. This refers to a continuation. Furthermore, if A and B are electrically connected, then A and B are directly connected. This includes cases where A and B are directly connected. Here, A and B are said to be directly connected via the above-mentioned object. However, it is possible to transmit electrical signals between A and B via wiring (or electrodes), etc. It refers to a certain type of connection. In other words, a direct connection is a connection that, when represented in an equivalent circuit, looks like the same circuit diagram. It refers to a connection that can be made.

[0284] In this specification, a switch means a conductive state (on state) or a non-conductive state (off state). It refers to a device that enters a state (F) and has the function of controlling whether or not to allow current to flow. Or, A switch is a device that has the function of selecting and switching the path through which electric current flows.

[0285] In this specification, channel length refers, for example, to the length of a semiconductor in a top view of a transistor. The body (or the part of the semiconductor through which current flows when the transistor is ON) and the gate The distance between the source and drain in the region where they overlap, or in the region where a channel is formed. It means separation.

[0286] In this specification, channel width refers to, for example, the state in which a semiconductor (or transistor) is ON. The region where the part of the semiconductor through which current flows (when in a certain state) and the gate electrode overlap, or channel This refers to the length of the portion where the source and drain face each other in the region where the drain is formed. .

[0287] In this specification, the terms "membrane," "layer," etc. may be used in some cases, or in a manner. Depending on the situation, they can be interchanged. For example, the term "conductive layer" can be replaced with " In some cases, the term can be changed to "conductive film." Or, for example, "insulating film." In some cases, it is possible to change the term "insulating layer" to "insulating layer." [Explanation of symbols]

[0288] BL_1: Wiring, MN1: Node, MN2: Node, RL_1: Wiring, RWL_1: Distribution Line, SL_1: wiring, SL_2: wiring, T1: period, T2: period, T3: period, T4: period Interval, T5: Period, T6: Period, T7: Period, T8: Period, T9: Period, WWL_1: Wiring WWL_2: Wiring, 10: Semiconductor equipment, 10_1: Semiconductor equipment, 10_4: Semiconductor equipment 10A: Semiconductor equipment, 10B: Semiconductor equipment, 10C: Semiconductor equipment, 10D: Semiconductor equipment 10E: Semiconductor device, 10F: Semiconductor device, 10G: Semiconductor device, 11: Transistor 11A: Transistor, 11B: Transistor, 11C: Transistor, 11D: Transistor Transistor, 11E: Transistor, 11F: Transistor, 11G: Transistor, 12 : Transistor, 12A: Transistor, 12B: Transistor, 12C: Transistor , 12D: transistor, 12E: transistor, 12F: transistor, 12G: transistor Transistor, 13: Transistor, 13A: Transistor, 13B: Transistor, 13C : Transistor, 13D: Transistor, 13E: Transistor, 13G: Transistor , 14: Capacitor, 15: Charge retention circuit, 30: Memory device, 31: Peripheral circuit, 32: - Decoder, 33: Word line driver circuit, 34: Bit line driver circuit, 35: Output circuit Path 36: Control logic circuit, 41: Column decoder, 42: Precharge circuit 43: Amplifier circuit, 44: Circuit, 51: Cell array, 61: Layer, 62: Layer, 300: Memory Device, 311: Substrate, 313: Semiconductor region, 314a: Low-resistance region, 314b: Low-resistance region 315: Insulator, 316: Conductor, 320: Insulator, 322: Insulator, 324: Insulator Body, 326: Insulator, 328: Conductor, 330: Conductor, 350: Insulator, 352: Insulator Body, 354: insulator, 356: conductor, 360: insulator, 362: insulator, 364: insulator Body, 366: Conductive, 370: Insulator, 372: Insulator, 374: Insulator, 376: Conductive Body, 380: insulator, 382: insulator, 384: insulator, 386: conductor, 402: insulator Body, 404: insulator, 503: conductor, 503a: conductor, 503b: conductor, 510: Insulator, 512: Insulator, 514: Insulator, 516: Insulator, 518: Conductor, 520: Insulator, 522: Insulator, 524: Insulator, 530: Oxide, 530a: Oxide, 530 b: oxide, 530c: oxide, 540a: conductor, 540b: conductor, 542: conductor 542a: Conductor, 542b: Conductor, 543a: Region, 543b: Region, 544: Insulator Edge material, 546: Conductor, 548: Conductor, 550: Insulator, 552: Insulator, 560: Conductor Electrical material, 560a: Conductor, 560b: Conductor, 574: Insulator, 580: Insulator, 581 : insulator, 582: insulator, 586: insulator, 610: conductor, 612: conductor, 620 : Conductors, 630: Insulators, 640: Insulators, 700: Electronic components, 702: Printed circuit boards 704: Mounting board, 730: Electronic component, 731: Interposer, 732: Package Substrate, 733: Electrode, 735: Semiconductor device, 7100: Robot, 7120: Aircraft, 7 140: Cleaning robot, 7160: Automobile, 7200: TV device, 7210: Smartphone 0: phon, 7220: PC, 7230: PC, 7232: keyboard, 7233: monitor device 7240: Game console, 7260: Game console, 7262: Controller

Claims

1. A first transistor, a second transistor, a capacitor, A first insulator and a second insulator, It comprises a first conductor, a second conductor, and a third conductor. The first transistor has silicon in the channel formation region, The second transistor has a metal oxide in the channel formation region. The first transistor has the first insulator, The second transistor is provided on the first insulator, The second transistor has the second insulator, The capacitor is provided on the second insulator, The first conductor is formed in the first insulator, The second conductor is formed in the second insulator, The third conductor is formed in the second insulator, The gate electrode of the first transistor is electrically connected to the first electrode of the capacitor via the first conductor and the second conductor. The first electrode of the capacitor is electrically connected to one of the source electrode and drain electrode of the second transistor via the third conductor. Semiconductor equipment.

2. A first transistor, a second transistor, a capacitor, A first insulator and a second insulator, It comprises a first conductor, a second conductor, and a third conductor. The first transistor has a metal oxide in the channel formation region. The second transistor has a metal oxide in the channel formation region. The first transistor has the first insulator, The second transistor is provided on the first insulator, The second transistor has the second insulator, The capacitor is provided on the second insulator, The first conductor is formed in the first insulator, The second conductor is formed in the second insulator, The third conductor is formed in the second insulator, The gate electrode of the first transistor is electrically connected to the first electrode of the capacitor via the first conductor and the second conductor. The first electrode of the capacitor is electrically connected to one of the source electrode and drain electrode of the second transistor via the third conductor. Semiconductor equipment.

3. In claim 1 or claim 2, The second transistor further has a back gate electrode. Semiconductor equipment.

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