Semiconductor device

Abstract

To provide a semiconductor device that can be embedded in an organism.SOLUTION: A semiconductor device that can be embedded in an organism includes a communication unit, a control unit, a storage unit, a calculation unit, and a sensor unit. The control unit has a function of controlling the communication unit, the calculation unit, and the storage unit. The storage unit has a function of keeping identification information. The calculation unit has a function of generating third information using first information and second information that is supplied from the sensor unit. The control unit has a function of causing the calculation unit to perform a calculation process in accordance with a signal input through the communication unit. The control unit has a function of outputting one of or both the identification information and the third information to the outside through the communication unit in accordance with the signal input through the communication unit. The calculation unit includes a transistor including an oxide semiconductor in a channel formation region. The semiconductor device is preferably covered with a covering material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field relates to an article, a method, or a manufacturing method. , process, machine, manufacture, or composition of matter (This is related to the above.)

[0003] In this specification and the like, a semiconductor device is a device that can function by utilizing semiconductor characteristics. It refers to semiconductor elements such as transistors and diodes, as well as semiconductor devices. The circuit is a semiconductor device. It is also applicable to display devices, light-emitting devices, lighting devices, electro-optical devices, and communication devices. Devices and electronic devices may include semiconductor elements and semiconductor circuits. , light-emitting devices, lighting devices, electro-optical devices, imaging devices, communication devices, and electronic devices are also made of semiconductors. It may be called the body apparatus. [Background technology]

[0004] In recent years, biometric features such as fingerprints, palm prints, vein patterns, voice prints, iris patterns, and retinal patterns have become increasingly common. The development of authentication devices that use biometric information such as face shape, body shape, etc. is underway. Vein authentication devices that use vein patterns are now in practical use at bank ATMs and other places. Patent Document 1 discloses an electronic device such as a smartphone that can perform fingerprint authentication. are. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-79415 Summary of the Invention [Problem to be solved by the invention]

[0006] Since biometric information is difficult to forge, authentication devices that use biometric information can achieve highly accurate identification. On the other hand, when biometric information changes due to injury, illness, aging, etc., it becomes difficult to identify individuals. There is a risk.

[0007] An object of one embodiment of the present invention is to provide a semiconductor device that can be implanted in a living body. Another object is to provide a semiconductor device capable of highly accurate individual identification. Another object of the present invention is to provide a semiconductor device with high reliability. Another object of the present invention is to provide a semiconductor device having a high resistance to light. This is one of the challenges.

[0008] The description of these problems does not preclude the existence of other problems. The embodiment does not necessarily solve all of these problems. Problems other than these may be solved by the description. The above is self-evident from the description, drawings, claims, etc. From the above descriptions, it is possible to extract other issues. [Means for solving the problem]

[0009] One aspect of the present invention is a semiconductor device that can be implanted in a living body, the semiconductor device comprising: a communication unit; a control unit; and a recording unit. The storage unit has a function of storing identification information, and the operation unit has a function of storing identification information. The calculation unit has a function of storing the first information and a function of converting the first information and the second information supplied from the sensor unit. and a function of generating third information using the signal input via the communication unit. In response, one or both of the identification information and the third information are output to the outside via the communication unit. the operation unit has a semiconductor transistor including an oxide semiconductor in a channel formation region. It is a body device.

[0010] The oxide semiconductor preferably contains at least one of indium and zinc. stomach.

[0011] The calculation unit may have a function of performing a product-sum calculation. For example, the first information is weight information. The semiconductor device according to an aspect of the present invention is preferably covered with a covering material. [Effects of the Invention]

[0012] According to one aspect of the present invention, a semiconductor device that can be implanted in a living body can be provided. It is possible to provide a semiconductor device that allows highly reliable individual identification. Alternatively, a semiconductor device with low power consumption can be provided. Alternatively, a novel semiconductor device can be provided. We can provide placement.

[0013] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have all of these effects. Effects other than these may be included in the description, This becomes clear from the description, drawings, claims, etc. From any description, it is possible to extract effects other than these. [Brief explanation of the drawings]

[0014] [Figure 1] Fig. 1A is a perspective view of a semiconductor device 100. Fig. 1B and Fig. 1C are diagrams illustrating an example of how the semiconductor device 100 is used. [Figure 2] 2A, 2B, 2C, 2D, and 2E are diagrams illustrating examples of use of the semiconductor device 100. FIG. [Figure 3] FIG. 3 is a block diagram illustrating the configuration of the communication unit. [Figure 4] FIG. 4 is a block diagram illustrating an example of the configuration of a semiconductor device. [Figure 5] 5A and 5B are diagrams illustrating an example of the configuration of a semiconductor device. [Figure 6] 6A and 6B are diagrams illustrating configuration examples of a memory circuit. [Figure 7] FIG. 7 is a diagram illustrating an example of the configuration of an arithmetic circuit. [Figure 8] FIG. 8 is a diagram illustrating an example of the operation of the semiconductor device. [Figure 9] FIG. 9 is a diagram illustrating an example of the configuration of a CPU. [Figure 10] 10A and 10B are diagrams illustrating an example of the configuration of a CPU. [Figure 11] FIG. 11 is a diagram illustrating an example of the configuration of a CPU. [Figure 12] FIG. 12 is a diagram illustrating an example of the structure of a semiconductor device. [Figure 13] 13A and 13B are diagrams illustrating examples of the structure of a transistor. DETAILED DESCRIPTION OF THE INVENTION

[0015] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention may be modified in various forms and details without departing from the spirit and scope of the present invention. Therefore, the present invention is based on the following embodiments. It should be noted that the following description of the invention is not intended to be limiting. In this case, the same parts or parts having similar functions are designated by the same reference numerals in different drawings. The explanation will be omitted here.

[0016] In addition, the position, size, range, etc. of each component shown in the drawings are for the purpose of facilitating understanding of the invention. Therefore, the actual location, size, range, etc. may not be shown. The invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings. In the actual manufacturing process, resist masks, etc., may be unintentionally damaged by etching or other processes. However, this may not be reflected in the diagram to make it easier to understand.

[0017] (Embodiment 1) A semiconductor device 100 according to one embodiment of the present invention will be described. 1 is a perspective view of a semiconductor device 100. The semiconductor device 100 includes a communication unit 110, a calculation unit 120, a control unit 130, a memory unit 140, and a sensor unit 150. The device 100 is covered with a covering material 190 .

[0018] The communication unit 110 receives signals sent from an external device (not shown) via wireless communication; The communication unit 110 also has the function of transmitting signals to external devices. It has the function of receiving power supplied contactlessly from the

[0019] The semiconductor device 100 may be provided with a battery. The battery has the function of storing the power required for the operation and the function of supplying the power required for the operation. As the battery, a primary battery or a secondary battery can be used. For example, a lithium ion secondary battery may be used.

[0020] The calculation unit 120 includes a calculation circuit 121 and a memory circuit 122. The memory circuit 122 has a function of performing arithmetic processing using information stored in the memory circuit 122. 1 performs arithmetic processing using information contained in the memory circuit 122 and information acquired by the sensor unit 150. The arithmetic circuit 121 also performs calculations using information stored in the storage unit 140. The calculation results are stored in the storage unit 140.

[0021] The storage unit 140 has a function of storing identification information of the semiconductor device 100. 40 has a function of storing programs and parameters related to the operation of the semiconductor device 100. The storage unit 140 is a DRAM (Dynamic Random Access Memory). Memory), SRAM (Static Random Access Memory), SRAM (Static Random Access Memory) RAM (Random Access Memory) and ROM (Read Only Memory) The storage unit 140 may be a non-volatile memory such as a memory-only memory. At least a part of the memory is preferably rewritable.

[0022] The control unit 130 controls the communication unit 110, the calculation unit 120, the storage unit 140, and the sensor unit 150. The control unit 130 has a function of controlling the operation of the sensor unit 150. The control unit 130 has a function of converting a log signal into a digital signal. In response to a signal supplied via 110, the identification information and / or the calculation result are transmitted to an external device. It has the function of transmitting to the device.

[0023] The sensor unit 150 may be a sensor capable of detecting various types of information. The sensor unit 150 measures temperature, vibration, pressure, gradient, acceleration, oxygen concentration, chemical substances, etc. The sensor unit 150 may have a function to detect at least one of the above. The signal processing unit 10 may have a function of converting the signal into a digital signal.

[0024] The semiconductor device 100 is preferably covered with a covering material 190. By using the covering material 190, After implantation in the living body, it is possible to make it difficult for inflammatory reactions, allergic reactions, etc. to occur. Furthermore, by covering the semiconductor device 100 with the covering material 190, blood vessels adjacent to the implanted site can be prevented from The covering material 190 can prevent damage to the living body such as nerve tissue. These include polymeric materials such as body-compatible glass, silicone resin, and fluororesin.

[0025] 1B and 1C are schematic diagrams showing a state in which the semiconductor device 100 is embedded in a living body 10. FIG. 1B shows a state in which the semiconductor device 100 is subcutaneously implanted between the thumb and index finger of a living body 10. FIG. 1C shows a state in which the semiconductor device 100 is embedded subcutaneously in the neck of a living body 10. This shows:

[0026] The semiconductor device 100 implanted in the living body 10 measures biological information such as the body temperature and heart rate of the living body 10. Furthermore, by providing the semiconductor device 100 with identification information specific to the living body 10, The semiconductor device 100 is attached to a personal identification card (for example, a personal number card (My Number Card)) driver's license, health insurance card, passport, cash card, credit card, etc. It can function as such.

[0027] For example, as shown in FIG. 2A, the semiconductor device 100 implanted in the living body 10 is connected to an external device 900. By placing the external device 900 on the semiconductor device, information on the living body 10 can be read out. a function of transmitting a signal to the semiconductor device 100 and a function of receiving a signal transmitted from the semiconductor device 100; The external device 900 functions as a reader / writer.

[0028] The semiconductor device 100 can be implanted in various living organisms. For example, the semiconductor device 100 shown in FIGS. As shown in E, the device can be embedded in a living body 21, a living body 22, a living body 23, a living body 24, or the like. By using the semiconductor device 100, it is possible to prevent theft of the living body 21 to the living body 24, grasp the behavior, and monitor the health condition of the living body 21 to the living body 24. It is possible to manage the status of the system.

[0029] <<Communication Unit 110>> 3 is a block diagram illustrating the configuration of the communication unit 110. The communication unit 110 includes an RF circuit 111. and an information processing circuit 117. The RF circuit 111 also includes a resonant circuit 112, a power supply The circuit 113 includes a clock generating circuit 114, a demodulating circuit 115, and a modulating circuit .

[0030] The resonant circuit 112 includes a power supply circuit 113, a clock generating circuit 114, a demodulation circuit 115, a modulation circuit 116, and a The resonant circuit 112 converts electromagnetic waves emitted from an external device into an AC signal. The signal contains information such as an operation command. The clock has a function of generating power from the signal to be used for the operation of the semiconductor device 100. The generating circuit 114 has a function of generating a synchronization signal necessary for the operation of the semiconductor device 100 from the signal. The demodulation circuit 115 has a function of extracting information such as operation commands from the signal. do.

[0031] The information processing circuit 117 extracts instructions from the information extracted from the demodulation circuit 115 and transmits them to the control unit 13. 0. The information processing circuit 117 also has a function of transmitting the information supplied from the control unit 130. The modulation circuit 116 has a function of supplying a signal to the modulation circuit 116. The modulation circuit 116 receives the signal from the control unit 130. The resonant circuit 112 functions to mix the modulated signal with a carrier wave. The mixed signal is then sent to the outside.

[0032] <<Arithmetic unit 120>> A semiconductor device 300 that can be used in the arithmetic unit 120 will be described. The arithmetic circuit 360 corresponds to the arithmetic circuit 121 of the arithmetic unit 120. corresponds to the memory circuit 122 of the calculation unit 120.

[0033] The semiconductor device 300 described in this embodiment has excellent computational efficiency and operates with extremely low power consumption. In other words, it is a computer that has the potential to mimic the functions of the human brain. It functions as a Brain Morphic Computer (BMC) This is a semiconductor device.

[0034] <Block diagram> FIG. 4 shows a block diagram illustrating the configuration of the semiconductor device 300. The semiconductor device 300 is The CPU 310 includes a PU 310, a bus 320, and an accelerator 330. The accelerator 330 includes a U-core 311 and a backup circuit 312. In addition to the operation block 331, a control circuit for controlling input and output of data between the operation blocks 331 It has a section 332.

[0035] The CPU 310 runs the operating system, controls data, and performs various calculations and programs. The CPU 310 has a function of performing general-purpose processing such as executing a program. The CPU core 311 corresponds to one or more CPU cores.

[0036] Furthermore, the CPU 310 can retain data in the CPU core 311 even if the supply of power supply voltage is stopped. The power supply voltage is supplied from the power supply domain (power domain). This can be controlled by electrically disconnecting the power supply from the power supply using a power switch or the like. The power supply voltage is sometimes called the drive voltage.

[0037] The backup circuit 312 is preferably an OS memory having an OS transistor, for example. Note that OS memory is a memory that uses an oxide semiconductor in the channel formation region, such as NOSRAM. This refers to memory that has an OS transistor. "AM (registered trademark)" means "Nonvolatile Oxide Semiconductor It is an abbreviation for "ctor RAM".

[0038] Metal oxides used in OS transistors include Zn oxide, Zn-Sn oxide, and Ga-S n-oxide, In-Ga oxide, In-Zn oxide, In-M-Zn oxide (M is Ti, Ga, Y, Zr, La, Ce, Nd, Sn or Hf). When using metal oxides in OS transistors, the ratio of elements can be adjusted to This is preferable because it allows a transistor to have excellent electrical characteristics such as effective mobility. , oxides containing indium and zinc, aluminum, gallium, yttrium, copper, Vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, Zr, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tantalum The alloy may contain one or more elements selected from the group consisting of tin, tungsten, magnesium, and the like.

[0039] To improve the reliability and electrical properties of OS transistors, metal oxides are used in the semiconductor layer. , CAAC-OS, CAC-OS, nc-OS, and other metal oxides having crystalline parts. CAAC-OS is a c-axis-aligned crystal CAC-OS is an abbreviation for Cine Oxide Semiconductor. loud-aligned composite oxide semiconductor nc-OS is an abbreviation of nanocrystalline oxide s It is an abbreviation for emissive.

[0040] In the off state, an OS transistor has a leakage current, which is a current that flows between the source and drain. NOSRAM has extremely low leakage current characteristics, allowing it to operate according to data. By storing the charge in the memory circuit, it can be used as a non-volatile memory. NOSRAM is capable of reading data without destroying it (non-destructive read). Since it is possible to read data multiple times, the neural network It is suitable for parallel processing of multiply-and-accumulate operations.

[0041] The band gap of metal oxides that function as oxide semiconductors is 2.5 eV or more. S transistors have extremely small off-state currents. For example, when the voltage between the source and drain is 3. At 5V and room temperature (25°C), the off-state current per 1µm of channel width is 1×10 -20 Less than A, 1 x 10 -22 Less than A or 1 x 10 -24 It can be less than A. Therefore, in OS memory, the amount of charge leaking from the storage node through the OS transistor is Therefore, the OS memory can function as a non-volatile memory circuit, so the CP This enables power gating of the U310.

[0042] The backup circuit 312, which is made up of an OS transistor, has a silicon a CPU core 311 that can be configured with a transistor (Si transistor) having The area of ​​the backup circuit 312 is the same as the area of ​​the CPU core 311. Since it is smaller, the backup circuit can be placed on the CPU core 311 without increasing the circuit area. The backup circuit 312 can be arranged in the CPU core 311. The backup circuit 312 has a function of holding the data in the register. The semiconductor layer including the channel formation region of a Si transistor is a single-crystal semiconductor. The semiconductor may be a solid or a polycrystalline semiconductor.

[0043] The control unit 332 has a memory circuit such as an SRAM inside. The output data obtained in block 331 is stored in the memory circuit. The output data is output to a plurality of semiconductor devices. Parallel calculations with an increased degree of parallelism can be performed using semiconductor devices.

[0044] The bus 320 electrically connects the CPU 310 and the accelerator 330. The U 310 and the accelerator 330 can transmit data via a bus 320. do.

[0045] <Operation block> The accelerator 330 described above executes a program (cursor) called from the host program. The accelerator 330 executes the kernel program. For example, parallel processing of matrix operations in graphics processing, multiplication in neural networks It is possible to perform parallel processing of sum operations and parallel processing of floating-point operations in scientific and technological calculations. Here, the accelerator 330 performs parallel arithmetic processing on multiple pieces of data ( An example of the configuration of the parallel processing operation block 331 will be described.

[0046] The arithmetic block 331 includes a plurality of arithmetic units 340 as shown in FIG. 5A. The arithmetic unit 340 includes a memory circuit 350 and an arithmetic circuit 360. 5A and 5B, the calculation circuit 360 calculates the following with respect to the XY plane in the figure: The memory circuits 350 are provided in different layers in a substantially perpendicular direction (Z direction in FIG. 5A). and the arithmetic circuit 360 are provided in a stacked configuration.

[0047] "Approximately perpendicular" refers to a state in which the angle is between 85 degrees and 95 degrees. In this specification, the X direction, Y direction, and Z direction shown in FIG. 5B etc. are mutually exclusive. The X and Y directions are parallel or perpendicular to the substrate surface. are approximately parallel, and the Z direction is perpendicular or approximately perpendicular to the substrate surface.

[0048] The memory circuit 350 has a plurality of memory cells. The readout is controlled by a drive circuit 341 and a drive circuit 342. The circuit 342 is also called a data control circuit.

[0049] The information (data) stored in the memory cells of the memory circuit 350 is used by the neural network. Weight is data (weight data) corresponding to the weight parameters used in the sum-of-products operation of the block. By converting data into digital data, the semiconductor device becomes noise-resistant and capable of high-speed calculations. The weight data may be analog data.

[0050] The memory circuit 350 is connected to the arithmetic circuit 360 via a wiring. The memory cell includes an OS transistor. The wiring is used to transmit the weight data from the storage circuit 350 to the arithmetic circuit 360. In order to read out weight data from the memory circuit 350 to the wiring at high speed, or to reduce the load caused by charging and discharging, To reduce energy consumption, it is preferable to shorten the wiring. As shown by the arrow 351 in FIG. 5B, the structure can be such that it extends in the z direction. By reducing the physical distance between the arithmetic circuit 360 and the memory circuit 350, for example, by stacking, This allows for shorter wiring distances, reducing the parasitic capacitance that occurs in signal lines, resulting in lower power consumption. It is possible to strengthen the system.

[0051] The arithmetic circuit 360 has a function of executing arithmetic processing such as a product-sum operation. The input and output of data is controlled by control circuits 343 and 344. The control circuit 343 and the control circuit 344 are also called data input / output circuits.

[0052] The arithmetic circuit 360 receives input data from the control circuit 343 and stores the data from the memory circuit 350. The input data is the biological information detected by the sensor unit 150. The resulting multiply-and-accumulate data is output to the control circuit 344. The data and weight data may be analog data or digital data. The input data and weight data are preferably digital data. Therefore, digital data is suitable for calculations that require highly accurate results. Suitable for processing.

[0053] By configuring the arithmetic circuit 360 with Si transistors, it is possible to stack the Si transistors and the OS transistors. That is, the memory circuit 350 formed of OS transistors can be It can be stacked with the arithmetic circuit 360 which can be configured with a resistor. Therefore, the area in which the memory circuit 350 can be arranged can be increased without increasing the circuit area. By arranging the memory circuit 350 in a region on the substrate where the arithmetic circuit 360 is provided, , the access is faster than when the memory circuit 350 and the arithmetic circuit 360 are arranged on the same layer. The memory capacity required for the calculation process in the calculator 330 can be increased. This reduces the number of times data used for arithmetic processing is transferred from an external storage device to the semiconductor device. This reduces power consumption.

[0054] <Memory circuit> An example of the configuration of a NOSRAM, which is a memory cell included in the memory circuit 350, will be described. In 6A, the write word is arranged in a matrix of M rows and N columns (M and N are natural numbers greater than or equal to 2). word lines WWL_1 to WWL_M, read word lines RWL_1 to RWL_M, write word lines Bit lines WBL_1 to WBL_N and wiring lines LBL_1 to LBL_N are shown. Also shown are memory cells 352 connected to each word line and bit line.

[0055] 6B is a diagram illustrating an example of a circuit configuration applicable to the memory cell 352. The cell 352 includes a transistor 353, a transistor 354, a transistor 355, and a capacitor. The transistor 356 (also called a capacitor) is also included.

[0056] One of the source and drain of the transistor 353 is connected to the write bit line WBL. The gate of the transistor 353 is connected to the write word line WWL. The other of the source and drain of the capacitor 353 is connected to one electrode of the capacitor element 356 and the transistor. The source or drain of the transistor 354 and the The other electrode of the capacitance element 356 is connected to a wiring that provides a fixed potential, for example, a ground potential. The other of the source and drain of the transistor 354 is connected to the source of the transistor 355. The gate of transistor 355 is connected to either the source or drain of the read word line. The other of the source and drain of the transistor 355 is connected to the line LB The wiring LBL is connected to the substrate surface on which the Si transistors of the arithmetic circuit 360 are provided. A calculation circuit 360 (not shown) is connected to the calculation circuit 360 via wiring extending in a direction substantially perpendicular to the surface. ) is connected.

[0057] As an example, the circuit configuration of the memory cell 352 shown in FIG. 6B is a three-transistor (3T) gate. Transistors 353 to 355 correspond to the NOSRAM of the OS In the off state, an OS transistor allows current to flow between the source and drain. NOSRAM has the characteristic of having extremely low leakage current. By using this to store the charge corresponding to the data in the memory circuit, it can be used as a non-volatile memory. You can be there.

[0058] <Arithmetic circuit> 7 shows a specific example of the configuration of the arithmetic circuit 360. In FIG. 7, weight data W and input data 7 shows an example of the configuration of an arithmetic circuit 360 that can perform a product-sum operation on data A. In the figure, a multiplication circuit 361, an addition circuit 362, and a register 363 are shown. The data multiplied by 361 is input to an adder circuit 362. The output of the adder circuit 362 is The data held in the register 363 and multiplied by the multiplication circuit 361 is added by the addition circuit 362. The register 363 is connected to the clock signal CLK and the reset This configuration allows the weight data W and the input data A data MAC equivalent to a multiply-and-accumulate operation with data A can be obtained.

[0059] <Example of operation> Then, part of the calculations of the program executed by the CPU 310 is executed by the accelerator 330. An example of the operation of the semiconductor device in this case will be described.

[0060] Figure 8 shows the case where part of the program calculations executed by the CPU are executed by the accelerator. FIG. 10 is a diagram illustrating an example of an operation.

[0061] The host program is executed by the CPU (host program execution; step S1).

[0062] The CPU allocates the data area required for calculations using the accelerator in the memory circuit. When an instruction to allocate a path (memory) is confirmed (memory allocation instruction; step S2), A data area is reserved in the storage circuit (memory) (memory reservation; step S3).

[0063] Next, the CPU transfers the input from the main memory or external storage device to the memory circuit (memory). The weight data is transmitted (data transmission; step S4). (i) receives the weight data and stores the weight data in the area secured in step S2. (data reception; step S5).

[0064] When the CPU confirms the instruction to start the kernel program (kernel program Step S6), the accelerator starts executing the kernel program (execution Calculation begins (step S7).

[0065] Immediately after the accelerator starts executing the kernel program, the CPU is put into a state where it performs calculations. to the PG (power gating) state (PG state transition; step S 8). In this case, just before the accelerator finishes executing the kernel program, the CPU The state is switched from the PG state to a state in which calculation is performed (PG state stop step S9). During the period from step S8 to step S9, the CPU is in the PG state, and the calculation processing system This allows the entire system to reduce power consumption and heat generation.

[0066] When the accelerator finishes executing the kernel program, the output data is sent to the accelerator. The calculation results are stored in a storage unit that holds the calculation results (calculation completed; step S10).

[0067] After the execution of the kernel program is completed, the CPU writes the output data stored in the memory to the memory. When a command to send data to in-memory or external storage device is confirmed (data transmission request Step S11), the output data is sent to the main memory or an external storage device. and stored in the main memory or an external storage device (data transmission; step S12). .

[0068] By repeating the above steps S1 to S12, the CPU and The accelerator reduces power consumption and heat generation while shifting some of the calculations performed by the CPU to the accelerator. The semiconductor device according to one embodiment of the present invention can be implemented as a non-Von Neumann type arc rectifier. Non-von Neumann architectures tend to disappear as processing speeds increase. Compared to the von Neumann architecture, which consumes more power, this architecture consumes significantly less power. Processing can be performed.

[0069] <CPUコア> Next, an example of a CPU 310 having a CPU core 311 capable of power gating will be described. I will explain.

[0070] 9 shows an example of the configuration of the CPU 310. The CPU 310 includes a CPU core ( ) 311, L1 (Level 1) cache memory device (L1 Cache) 371, L2 cache Cache memory device (L2 Cache) 372, bus interface unit (Bus I The power supply 314 includes a power switch (315) 316, a power filter (317), a level shifter (LS) 318, and a power supply 319. The CPU core 311 includes a flip-flop 314 .

[0071] The bus interface unit 373 connects the CPU core 311 and the L1 cache memory device 371 and L2 cache memory device 372 are interconnected.

[0072] Interrupt signals input from the outside, signals issued by the CPU 310 In response to signals such as SLEEP1, PMU313 outputs clock signal GCLK1 and various PG (Power gating) Control signals are generated. The clock signal GCLK1 and the PG control signal are input to the CPU 310. controls the power switches 315 to 317 and the flip-flop 314.

[0073] The power switches 315 and 316 are connected to a virtual power line V_VDD (hereinafter referred to as the V_VDD line). The power switch 317 controls the supply of voltages VDDD and VDD1 to the It controls the supply of voltage VDDH to the shifter (LS) 318. The voltage VSSS is input to the PMU 313 without going through a power switch. The voltage VDDD is input without going through a power switch.

[0074] Voltages VDDD and VDD1 are drive voltages for the CMOS circuit. Voltage VDD1 is voltage VDD The voltage VDDH is the drive voltage for the OS transistors. This is the drive voltage and is higher than the voltage VDDD.

[0075] L1 cache memory device 371, L2 cache memory device 372, bus interface Each of the base units 373 has at least one power domain that can be power gated. A power-gating capable power domain has one or more power switches. These power switches are controlled by a PG control signal.

[0076] The flip-flop 314 is used as a register. A backup circuit is provided. The flip-flop 314 will now be described.

[0077] FIG. 10A shows an example of the circuit configuration of the flip-flop 314. Flip-flop 314 is a scan flip-flop 319 , and a backup circuit 312.

[0078] The scan flip-flop 319 is connected to nodes D1, Q1, SD, SE, RT, CK, and The clock buffer circuit 319A is included.

[0079] Node D1 is a data input node, and node Q1 is a data output node. The node SD is an input node for scan test data. The node SE is a signal SCE The node CK is the input node for the clock signal GCLK1. The clock signal GCLK1 is input to the clock buffer circuit 319A. The analog switch of the chip 319 is connected to the nodes CK1 and CK2 of the clock buffer circuit 319A. B1. Node RT is the input node for the reset signal. It is Do.

[0080] The signal SCE is a scan enable signal and is generated by the PMU 313. The level shifter 318 level-shifts the signals BK and RC. , signals BKH and RCH are generated. Signal BK is a backup signal, and signal RC is a recovery signal. This is the number.

[0081] The circuit configuration of the scan flip-flop 319 is not limited to that shown in FIG. Flip-flops available in the library can be applied.

[0082] The backup circuit 312 includes nodes SD_IN, SN11, and transistors M11 to M13. , and a capacitive element C11.

[0083] The node SD_IN is the input node for scan test data and is connected to the scan flip-flop. Node SN11 is connected to node Q1 of backup circuit 319. The capacitance element C11 is a storage capacitance for holding the voltage of the node SN11. do.

[0084] The transistor M11 controls the conduction state between the node Q1 and the node SN11. The transistor M12 controls the conduction state between the node SN11 and the node SD. The conduction state between the node SD_IN and the node SD is controlled by the transistors M11 and M13. The on / off of the transistor M11 is controlled by the signal BKH, and the on / off of the transistor M12 is controlled by the signal RCH. can be.

[0085] The transistors M11 to M13 correspond to the transistors 352 included in the memory cell 352. Transistors M11 to M13 are OS transistors, as are transistors M3 to M5. The back gates of the transistors M11 to M13 are It is connected to the power supply line that supplies the voltage VBG1.

[0086] At least the transistors M11 and M12 are preferably OS transistors. The extremely low current characteristic of the OS transistor allows the voltage at node SN11 to drop. It can suppress the power consumption and consumes almost no power to store data, so it is The backup circuit 312 has nonvolatile characteristics. Data is written by charging and discharging the capacitance element C11. Therefore, the backup circuit 312 is theoretically not limited in the number of times it can be rewritten. Data can be written and read using electrical power.

[0087] It is highly preferred that all transistors in the backup circuit 312 are OS transistors. As shown in FIG. 10B, a scan flip-flop consisting of a silicon CMOS circuit is A backup circuit 312 can be stacked on top of the flip 319 .

[0088] The backup circuit 312 has a much smaller number of elements than the scan flip-flop 319. Since the number of scan flip-flops 319 is small, the backup circuit 312 is stacked. In other words, the backup circuit 312 is a general-purpose It is a highly versatile backup circuit. Also, it is equipped with scan flip-flops 319. Since the backup circuit 312 can be provided in the area where the backup Even if the circuit 312 is incorporated, the increase in the area occupied by the flip-flop 314 can be made zero. Therefore, providing the backup circuit 312 in the flip-flop 314 This enables power gating of the CPU core 311. Because of the low power consumption, it is possible to power-gate the CPU core 311 with high efficiency. do.

[0089] By providing the backup circuit 312, the parasitic capacitance of the transistor M11 is reduced. This is due to the parasitic capacitance of the logic circuit connected to node Q1. Since it is relatively small, it does not affect the operation of the scan flip-flop 319. The backup circuit 312 does not substantially degrade the performance of the flip-flop 314. .

[0090] The low power consumption state of the CPU core 311 may be, for example, a clock gating state, a power The PMU313 can set the gating state and the pause state. Based on the signal SLEEP1, etc., the low power consumption mode of the CPU core 311 is selected. For example, When transitioning from normal operation to clock gating, the PMU313 The generation of the signal GCLK1 is stopped.

[0091] For example, when going from normal operation to hibernation, the PMU313 adjusts the voltage and / or For example, when performing voltage scaling, the PMU313 , the power switch 315 is turned off to input the voltage VDD1 to the CPU core 311, The power switch 316 is turned on. The voltage VDD1 is applied to the scan flip-flop 319. When frequency scaling is performed, the PMU313 The frequency of clock signal GCLK1 is reduced.

[0092] When the CPU core 311 is shifted from the normal operation state to the power gating state, An operation of backing up the data of the flip-flop 319 to the backup circuit 312 When the CPU core 311 is returned from the power gating state to the normal operation state, In order to recover the data in the backup circuit 312 to the scan flip-flop 319, The following action is taken.

[0093] FIG. 11 shows an example of a power gating sequence for the CPU core 311. In FIG. 1, t1 to t7 represent time. Signals PSE0 to PSE2 are This is a control signal for the switches 315 to 317 and is generated by the PMU 313. When the signal PSE1 and PSE2 are at "L", the power switch 315 is on / off. The same applies to

[0094] Before time t1, the power supply is in a normal operation state. The switch 315 is on, and the voltage VDDD is input to the CPU core 311. The flip-flop 319 operates normally. At this time, the level shifter 318 operates. Since there is no need for this, the power switch 317 is off and the signals SCE, BK, and RC are low. Since the node SE is at "L", the scan flip-flop 319 reads the signal at the node D1 In the example of FIG. 11, at time t1, the backup circuit 31 The node SN11 of 2 is at "L".

[0095] The operation during backup is explained below. At time t1, the PMU313 The clock signal GCLK1 is stopped, and the signals PSE2 and BK are set to "H". It becomes active and outputs a signal BKH of “H” to the backup circuit 312 .

[0096] The transistor M11 of the backup circuit 312 is turned on, and the scan flip-flop The data at node Q1 of 319 is written to node SN11 of backup circuit 312. If the node Q1 of the scan flip-flop 319 is at "L", the node SN11 is at " If the node Q1 remains at "L" and the node Q2 is at "H", the node SN11 goes to "H".

[0097] At time t2, the PMU313 sets the signals PSE2 and BK to "L" and at time t3, the PMU313 sets the signal PSE0 At time t3, the state of the CPU core 311 transitions to the power gating state. The signal PSE0 may fall at the same timing as the signal BK falls.

[0098] The operation during power gating will be explained. "When it goes low, the voltage on the V_VDD line drops, and the data on node Q1 is lost. Node SN11 continues to hold the data of node Q1 at time t3.

[0099] The operation during recovery will be explained. At time t4, the PMU 313 outputs the signal P By setting SE0 to "H", the device transitions from the power gating state to the recovery state. Charging of the _VDD line begins, and the voltage of the V_VDD line reaches VDDD (time t5). Then, PMU313 sets signals PSE2, RC, and SCE to "H".

[0100] The transistor M12 is turned on, and the charge of the capacitor C11 is transferred to the nodes SN11 and SD If node SN11 is "H", the voltage of node SD rises. Since the node SE is "H", the node is not input to the input side latch circuit of the scan flip-flop 319. At time t6, the clock signal GCLK1 is input to the node CK. Then, the data in the input latch circuit is written to node Q1. This means that 11 data items have been written to node Q1.

[0101] At time t7, the PMU313 sets the signals PSE2, SCE, and RC to "L" and the recovery operation begins. Finish.

[0102] The backup circuit 312 using OS transistors has both dynamic and static low power consumption. Its small size makes it ideal for normally-off computing. The CPU 310 includes a CPU core 311 having a backup circuit 312 using a resistor. The NoffCPU is a nonvolatile memory It has a memory, and when operation is not required, the power supply can be stopped. Even with the CPU 314 installed, there is almost no performance degradation or increase in dynamic power consumption compared to the CPU core 311. We can prevent this from happening.

[0103] The CPU core 311 may have multiple power domains that can be power gated. Multiple power domains may have one or more power switches to control the voltage input. The CPU core 311 is provided with one or more power gating switches. For example, power gating may not be performed. The power domain controls the flip-flop 314 and the power switches 315 to 317. A power gating control circuit may be provided to achieve this.

[0104] The application of the flip-flop 314 is not limited to the CPU 310. In this case, a flip-flop is provided in a register provided in a power domain that can be power gated. Tip 314 can be applied.

[0105] The configurations, structures, methods, and the like shown in this embodiment may be different from the configurations, structures, methods, and the like shown in other embodiments. It can be used in combination with other methods as appropriate.

[0106] (Embodiment 2) In this embodiment mode, a transistor structure applicable to the semiconductor device described in the above embodiment mode will be described. As an example, a structure in which transistors having different electrical characteristics are stacked will be described. This configuration will be described. By adopting this configuration, the degree of freedom in designing a semiconductor device can be increased. Furthermore, by stacking transistors with different electrical characteristics, The integration of the device can be increased.

[0107] A part of the cross-sectional structure of the semiconductor device is shown in FIG. 550, a transistor 500, and a capacitance element 600. 13A is a cross-sectional view of the channel length of transistor 500, and FIG. 13B is a cross-sectional view of the channel length of transistor 500. For example, the transistor 500 may be the same as the memory circuit shown in the above embodiment. The OS transistor included in the transistor 350, that is, a transistor having an oxide semiconductor in a channel formation region, The transistor 550 corresponds to the arithmetic circuit 3 shown in the above embodiment. 60 has a Si transistor, that is, a transistor having silicon in the channel forming region The capacitor 600 corresponds to the capacitor included in the memory circuit 350.

[0108] The transistor 500 is an OS transistor. Therefore, the data voltage written to the storage node via the transistor 500 is In other words, the frequency of refresh operations of the storage nodes can be reduced. Since the frequency is reduced or refresh operation is not required, the power consumption of the semiconductor device is reduced. It can be reduced.

[0109] In FIG. 12, the transistor 500 is provided above the transistor 550, and the capacitive element 60 0 is provided above transistor 550 and transistor 500.

[0110] The transistor 550 is provided on a substrate 411. The substrate 411 is, for example, a p-type silicon The substrate 411 may be an n-type silicon substrate. The oxide layer 414 is 11 is an insulating layer (BOX) formed by buried oxide. The transistor 550 is preferably a silicon oxide layer. 411 via an oxide layer 414, a single crystal silicon, so-called SOI (Silicon on Insulator) Therefore, in this embodiment, In this case, the transistor 550 is a Si transistor.

[0111] The substrate 411 in the SOI substrate is provided with an insulator 413 that functions as an element isolation layer. The substrate 411 also has a well region 412. The well region 412 is a region where the transistor 5 The region is given n-type or p-type conductivity depending on the conductivity type of the SOI substrate. The single crystal silicon in the semiconductor region 415, which functions as a source region or a drain region, A low resistance region 416a and a low resistance region 416b are provided on the well region 412. has a low resistance region 416c.

[0112] The transistor 550 is formed on a well region 412 to which an impurity element is added to give conductivity. The well region 412 can be provided with an independent potential via the low resistance region 416c. By changing the gate electrode of the transistor 550, Therefore, the threshold voltage of the transistor 550 can be controlled. Applying a negative potential to well region 412 reduces the threshold voltage of transistor 550. Therefore, the off-current can be reduced by increasing the current density of the well region 412. By applying a negative potential to the gate electrode of the Si transistor, the potential applied to the gate electrode of the Si transistor becomes 0V. As a result, the drain current of the semiconductor device having the transistor 550 can be reduced. The power consumption of the semiconductor device can be reduced, and the calculation efficiency can be improved.

[0113] The transistor 550 has a top surface of a semiconductor layer and a side surface in a channel width direction, which are formed with an insulator 417 interposed therebetween. It is preferable that the transistor is a so-called fin type, which is covered with a conductor 418. By making the transistor 550 a fin type, the effective channel width is increased, The on-state characteristics of the transistor 550 can be improved. Since the voltage Vcc can be reduced, the off-state characteristics of the transistor 550 can be improved.

[0114] The transistor 550 may be a p-channel transistor or an n-channel transistor. Either a transistor or a gate driver may be used.

[0115] The conductor 418 may function as a first gate (also called a top gate) electrode. The well region 412 may also function as a second gate (also called a bottom gate) electrode. In this case, the potential applied to the well region 412 is applied via the low resistance region 416c. It can be controlled.

[0116] The region where the channel of the semiconductor region 415 is formed, the region nearby, the source region, or the drain region The low resistance region 416a and the low resistance region 416b, which are to be the drain region, and the well region 412 In the low resistance region 416c connected to the electrode for controlling the potential, a silicon-based semiconductor It is preferable that the semiconductor contains a material selected from the group consisting of silicon and silicon dioxide, and it is preferable that the semiconductor contains a material selected from the group consisting of silicon dioxide and silicon dioxide. (germanium), SiGe (silicon germanium), GaAs (gallium arsenide), G It may also be formed from a material having a crystal lattice such as gallium aluminum arsenide (AlAs). The structure is made of silicon, in which the effective mass is controlled by applying stress to the silicon and changing the lattice spacing. Alternatively, the transistor 550 may be made of H by using GaAs and GaAlAs. EMT (High Electron Mobility Transistor) That's fine.

[0117] Well region 412, low resistance region 416a, low resistance region 416b, and low resistance region 416 c is a semiconductor material applied to the semiconductor region 415, as well as an n-type conductive material such as arsenic or phosphorus. It contains an element that imparts p-type conductivity, or an element that imparts p-type conductivity, such as boron.

[0118] The conductor 418 that functions as the gate electrode is made of an element that gives n-type conductivity, such as arsenic or phosphorus. Semiconductor materials such as silicon that contain elements that impart p-type conductivity, such as silicon or boron A conductive material such as a metal material, an alloy material, or a metal oxide material can be used. The conductor 418 may also be made of a silicide such as nickel silicide.

[0119] In addition, since the work function is determined by the conductor material, by selecting the conductor material, Specifically, the threshold voltage of the transistor can be adjusted by using titanium nitride as the conductor. It is preferable to use materials such as tantalum nitride or tantalum nitride. To achieve this, metal materials such as tungsten and aluminum are used as layers for the conductor. is preferable, and tungsten is particularly preferable in terms of heat resistance.

[0120] The low resistance region 416a, the low resistance region 416b, and the low resistance region 416c are formed of another conductive material, For example, a structure in which silicide such as nickel silicide is stacked may be used. By doing so, the conductivity of the region that functions as an electrode can be increased. The side of the conductor 418 functions as a gate electrode, and the insulating layer functions as a gate insulating layer. The side surfaces of the body 417 are provided with insulating layers that function as sidewall spacers (also called sidewall insulating layers). By using such a structure, the conductor 418 and the low resistance region 4 This can prevent the conductive state between the low-resistance region 16a and the low-resistance region 416b.

[0121] Over the transistor 550, an insulator 420, an insulator 422, an insulator 424, and an insulator The bodies 426 are stacked one on top of the other.

[0122] The insulators 420, 422, 424, and 426 may be, for example, oxide. Silicon, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, oxide Aluminum oxynitride, aluminum nitride oxide, aluminum nitride, etc. may be used.

[0123] In this specification, silicon oxynitride refers to a material containing more oxygen than nitrogen as its composition. Silicon nitride oxide refers to a material that contains more nitrogen than oxygen. In this specification, aluminum oxynitride refers to a material with a large amount of aluminum. It refers to a material that contains more oxygen than nitrogen, and aluminum oxide nitride is a material with a indicates a material that contains more nitrogen than oxygen.

[0124] The insulator 422 smooths out the steps caused by the transistor 550 and other components provided below it. For example, the top surface of the insulator 422 may have a function as a planarizing film. To improve flatness, the surface is flattened by a planarization process such as chemical mechanical polishing (CMP). It's fine.

[0125] The insulator 424 also includes a substrate 411 or a transistor 550. A film having a barrier property that prevents hydrogen and impurities from diffusing is used in the area where the capacitor 500 is provided. It is preferable that

[0126] An example of a film having a barrier property against hydrogen is silicon nitride formed by a CVD method. Here, a semiconductor having an oxide semiconductor such as the transistor 500 can be used. When hydrogen diffuses into the element, the characteristics of the semiconductor element may be deteriorated. A film that suppresses hydrogen diffusion is used between the transistor 500 and the transistor 550. Specifically, the film that suppresses hydrogen diffusion is a film that has a small amount of hydrogen desorption. The membrane.

[0127] The amount of desorbed hydrogen can be analyzed using, for example, thermal desorption spectroscopy (TDS). For example, the amount of hydrogen desorption from the insulator 424 can be measured by TDS analysis when the surface temperature of the film is 5 In the range of 0 to 500°C, the amount of desorption converted to hydrogen atoms is Converted to 10 x 10 15 atoms / cm 2 Less than or equal to 5 x 10 15 at oms / cm 2 The following is fine.

[0128] It is preferable that the insulator 426 has a lower dielectric constant than the insulator 424. For example, The dielectric constant of the insulator 426 is preferably less than 4, more preferably less than 3. The relative dielectric constant of the insulating material 26 is preferably 0.7 times or less, and more preferably 0.6 times or less, of the relative dielectric constant of the insulating material 424. It is more preferable to use a material with a low dielectric constant as the interlayer film to reduce the parasitic capacitance that occurs between wiring. It is possible.

[0129] The insulators 420, 422, 424, and 426 are connected to the capacitor element 6. 00, or the conductor 428 and the conductor 430 connected to the transistor 500 are filled in. The conductors 428 and 430 are plugs or wiring. In addition, the conductor having the function of a plug or wiring may have a plurality of configurations. In addition, in this specification and the like, a wiring and a wiring-connected The conductive material may be an integral part of the plug that connects to the conductive material. In some cases, a part of the conductor functions as a plug.

[0130] The materials for each plug and wiring (conductor 428, conductor 430, etc.) include metal materials, alloys, and the like. Conductive materials such as gold, metal nitride, or metal oxide materials are used as single or multilayered layers. High-melting materials such as tungsten and molybdenum, which have both heat resistance and electrical conductivity, can be used. It is preferable to use a point material, and it is preferable to use tungsten. It is preferable to form the wiring layer from a low-resistance conductive material such as aluminum or copper. This can reduce the wiring resistance.

[0131] A wiring layer may be provided over the insulator 426 and the conductor 430. For example, in FIG. An insulator 450, an insulator 452, and an insulator 454 are stacked in this order. A conductor 456 is formed in the insulators 450, 452, and 454. The conductor 456 functions as a plug or wiring that connects to the transistor 550. Note that the conductor 456 is made of a material similar to that of the conductors 428 and 430. It can be established.

[0132] For example, the insulator 450 has a barrier property against hydrogen, similar to the insulator 424. It is preferable to use an insulator. In addition, the conductor 456 has a barrier property against hydrogen. It is preferable that the insulating material 450 contains a conductor. In particular, the insulating material 450 has a barrier property against hydrogen. In the opening, a conductor having a barrier property against hydrogen is formed. The transistor 550 and the transistor 500 may be separated by a barrier layer. This can suppress the diffusion of hydrogen from the resistor 550 to the transistor 500.

[0133] As a conductor having a barrier property against hydrogen, for example, tantalum nitride or the like is used. In addition, by laminating tantalum nitride and highly conductive tungsten, The diffusion of hydrogen from the transistor 550 can be suppressed while maintaining the conductivity of the transistor 550. In this case, the tantalum nitride layer having a barrier property against hydrogen has a barrier property against hydrogen. It is preferable that the insulating material 450 is in contact with the insulating material 450 .

[0134] A wiring layer may be provided over the insulator 454 and the conductor 456. For example, in FIG. An insulator 460, an insulator 462, and an insulator 464 are stacked in this order. A conductor 466 is formed in the insulators 460, 462, and 464. The conductor 466 functions as a plug or wiring. The conductive material 428 and the conductive material 430 can be formed using similar materials.

[0135] For example, the insulator 460 has a barrier property against hydrogen, similar to the insulator 424. It is preferable to use an insulator. In addition, the conductor 466 has a barrier property against hydrogen. It is preferable that the insulator 460 contains a conductor. In particular, the insulator 460 has a barrier property against hydrogen. In the opening, a conductor having a barrier property against hydrogen is formed. The transistor 550 and the transistor 500 may be separated by a barrier layer. This can suppress the diffusion of hydrogen from the resistor 550 to the transistor 500.

[0136] A wiring layer may be provided over the insulator 464 and the conductor 466. For example, in FIG. An insulator 470, an insulator 472, and an insulator 474 are stacked in this order. A conductor 476 is formed on the insulators 470, 472, and 474. The conductor 476 functions as a plug or wiring. The conductive material 428 and the conductive material 430 can be formed using similar materials.

[0137] For example, the insulator 470 has a barrier property against hydrogen, similar to the insulator 424. It is preferable to use an insulator. In addition, the conductor 476 has a barrier property against hydrogen. It is preferable that the insulating material 470 contains a conductor. In particular, the insulating material 470 has a barrier property against hydrogen. In the opening, a conductor having a barrier property against hydrogen is formed. The transistor 550 and the transistor 500 may be separated by a barrier layer. This can suppress the diffusion of hydrogen from the resistor 550 to the transistor 500.

[0138] A wiring layer may be provided over the insulator 474 and the conductor 476. For example, in FIG. An insulator 480, an insulator 482, and an insulator 484 are stacked in this order. A conductor 486 is formed on the insulators 480, 482, and 484. The conductor 486 functions as a plug or wiring. The conductive material 428 and the conductive material 430 can be formed using similar materials.

[0139] For example, the insulator 480 has a barrier property against hydrogen, similar to the insulator 424. It is preferable to use an insulator. In addition, the conductor 486 has a barrier property against hydrogen. It is preferable that the insulating material 480 contains a conductor. In particular, the insulating material 480 has a barrier property against hydrogen. In the opening, a conductor having a barrier property against hydrogen is formed. The transistor 550 and the transistor 500 may be separated by a barrier layer. This can suppress the diffusion of hydrogen from the resistor 550 to the transistor 500.

[0140] In the above, the wiring layer including the conductor 456, the wiring layer including the conductor 466, and the conductor 476 The wiring layer including the conductor 486 has been described above. The semiconductor device is not limited to this. Alternatively, the number of wiring layers may be three or less, or five or more wiring layers similar to the wiring layer including the conductor 456 may be used. Good too.

[0141] On the insulator 484, an insulator 510, an insulator 512, an insulator 514, and an insulator 516 are formed. , and are stacked in this order. It is preferable that either of the insulating layers 516 is made of a material that has a barrier property against oxygen or hydrogen. stomach.

[0142] For example, the insulator 510 and the insulator 514 may include, for example, the substrate 411 or the transistor. The region where the transistor 500 is provided is filled with hydrogen and impurities. Therefore, it is preferable to use a film having a barrier property against the insulator 424. Materials can be used.

[0143] As an example of a film with barrier properties against hydrogen, silicon nitride formed by CVD is used. Here, a semiconductor element including an oxide semiconductor such as the transistor 500 can be The diffusion of hydrogen may deteriorate the characteristics of the semiconductor device. A film that suppresses hydrogen diffusion is used between the transistor 500 and the transistor 550. is preferred.

[0144] In addition, as a film having a barrier property against hydrogen, for example, an insulator 510 and an insulator 5 14 uses metal oxides such as aluminum oxide, hafnium oxide, and tantalum oxide. It is preferable.

[0145] In particular, aluminum oxide is a material that can absorb oxygen and hydrogen, which can cause fluctuations in the electrical characteristics of transistors. Therefore, it has a high blocking effect that prevents impurities such as acid and moisture from passing through the membrane. Aluminum oxide is resistant to hydrogen, moisture, etc. during and after the transistor manufacturing process. It is possible to prevent impurities from being mixed into the transistor 500. This can suppress the release of oxygen from the oxide that makes up the transistor. Suitable for use as a protective film against 500.

[0146] For example, the insulators 512 and 516 may be made of the same material as the insulator 420. In addition, by using materials with a relatively low dielectric constant for these insulators, , the parasitic capacitance occurring between the wirings can be reduced. The body 516 may be a silicon oxide film, a silicon oxynitride film, or the like.

[0147] In addition, the insulators 510, 512, 514, and 516 are provided with conductors 5 18, and conductors (for example, conductor 503) that constitute the transistor 500 are embedded. The conductor 518 is connected to the capacitor 600 or the transistor 550. The conductor 518 functions as a plug or wiring. The conductor 430 can be formed using a material similar to that of the conductor 430 .

[0148] In particular, the insulator 510 and the conductor 518 in the area in contact with the insulator 514 are free of oxygen, hydrogen, It is preferable that the conductive material has a barrier property against water. The transistor 550 and the transistor 500 have a barrier property against oxygen, hydrogen, and water. The layer separating the transistor 550 from the transistor 500 can separate the hydrogen Diffusion can be suppressed.

[0149] Above the insulator 516 is the transistor 500 .

[0150] As shown in FIGS. 13A and 13B, transistor 500 includes an insulator 514 and an insulator The conductor 503 is disposed so as to be embedded in the insulator 516, and the insulator 516 and the conductor 5 an insulator 522 disposed on the insulating layer 523; and an insulator 524 disposed on the insulating layer 522. An oxide 530a disposed on the insulator 524 and an oxide 530b disposed on the oxide 530a. The oxide 530b is a conductive material 542a and a conductive material 542b that are spaced apart from each other on the oxide 530b. 542b, and the conductor 542a and the conductor 542b are disposed on the conductor 542a and the conductor 542b. The insulating body 580 has an opening formed therein and overlaps the insulating body 542b. and a conductor 560 disposed on the surface of the insulator 545. .

[0151] 13A and 13B, the oxide 530a, the oxide 530b, the conductor 542a, and an insulator 544 is disposed between the conductor 542b and the insulator 580. 13A and 13B, the conductor 560 is preferably formed between the insulator 54 5, and a conductor 560a provided inside the conductor 560a. 13A and 13B, the conductor 560b is preferably formed on the substrate 500. As shown, insulator 574 is disposed over insulator 580, conductor 560, and insulator 545. It is preferable that the

[0152] In this specification and the like, the oxide 530a and the oxide 530b are collectively referred to as oxides. Sometimes it's 530.

[0153] In the transistor 500, the region where the channel is formed and the vicinity thereof are oxidized. 5 shows a structure in which two layers of a metal 530a and an oxide 530b are stacked. For example, a single layer of oxide 530b or a stack of three or more layers may be used. A configuration may be provided.

[0154] In addition, although the conductor 560 in the transistor 500 has a two-layer structure, The invention is not limited to this. For example, the conductor 560 may have a single layer structure. However, it may have a laminated structure of three or more layers. The transistor 500 is an example, and is not limited to this configuration. The circuit configuration, driving method, etc. Appropriate transistors may be used accordingly.

[0155] Here, the conductor 560 functions as the gate electrode of the transistor, and the conductors 542a and The conductor 542b functions as a source electrode and a drain electrode, respectively. As shown, the conductor 560 is inserted through the opening in the insulator 580 and the conductors 542a and 542b. The conductor 560, the conductor 542a, and the conductor 542b are formed so as to be embedded in the sandwiched region. The placement of the conductive material 542b is selected to be self-aligned with the opening of the insulator 580. In the transistor 500, the gate electrode is connected between the source electrode and the drain electrode. Therefore, the conductor 560 can be positioned with a margin for alignment. Since the transistor 500 can be formed without any additional steps, the area occupied by the transistor 500 can be reduced. This allows for miniaturization and high integration of semiconductor devices.

[0156] Furthermore, a conductor 560 is formed in a self-aligned manner in the region between the conductors 542a and 542b. Therefore, the conductor 560 has an overlapping area with the conductor 542a or the conductor 542b. This prevents the formation of a gap between the conductor 560 and the conductors 542a and 542b. Therefore, the parasitic capacitance of the transistor 500 can be reduced. It is possible to improve the speed and have high frequency characteristics.

[0157] The conductor 560 may function as a first gate (also called a top gate) electrode. The conductor 503 may function as a second gate (also called a bottom gate) electrode. In this case, the potential applied to the conductor 503 is linked to the potential applied to the conductor 560. The threshold voltage of the transistor 500 can be controlled by changing it independently. In particular, applying a negative potential to the conductor 503 It is possible to increase the threshold voltage and reduce the off-current. Applying a negative potential to the conductor 503 increases the potential applied to the conductor 560 compared to not applying a negative potential. The drain current when the potential is 0V can be reduced.

[0158] The conductor 503 is arranged to overlap the oxide 530 and the conductor 560. Therefore, when a potential is applied to the conductor 560 and the conductor 503, The electric field generated by the conductor 503 is connected to the electric field generated by the conductor 503, and the chalcogenide formed in the oxide 530 The chel forming area can be covered.

[0159] In this specification, a pair of gate electrodes (a first gate electrode and a second gate electrode) The structure of a transistor in which the channel formation region is electrically surrounded by the electric field of This is called a surrounded channel (S-channel) configuration. The disclosed S-channel configuration is different from the Fin type and planar type configurations. By adopting a -channel structure, the resistance to short channel effects is increased. This makes it possible to provide a transistor in which the short channel effect is less likely to occur.

[0160] The conductor 503 has the same structure as the conductor 518, and the insulators 514 and 5 Conductor 503a is formed in contact with the inner wall of opening 16, and conductor 503b is formed further inside. In the transistor 500, the conductor 503a and the conductor 503b are Although a stacked structure is shown, the present invention is not limited to this. The electric conductor 503 may be provided as a single layer or as a laminated structure of three or more layers.

[0161] Here, the conductor 503a prevents 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 the function of suppressing the impurities (i.e., the impurities are less likely to permeate). Alternatively, the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.) is suppressed. It is preferable to use a conductive material that has the above-mentioned function (i.e., that is difficult for oxygen to permeate). In this specification, the function of suppressing the diffusion of impurities or oxygen means the function of suppressing the diffusion of the above impurities or oxygen. The function is to suppress the diffusion of any one or all of the above oxygen.

[0162] For example, the conductor 503a has a function of suppressing the diffusion of oxygen, so that the conductor 503b This can prevent the conductivity from decreasing due to oxidation.

[0163] When the conductor 503 also functions as a wiring, the conductor 503b is made of tungsten, copper, Alternatively, it is preferable to use a highly conductive material containing aluminum as a main component. In this embodiment, the conductor 503 is illustrated as a stack of conductors 503a and 503b. However, the conductor 503 may have a single layer structure.

[0164] The insulator 522 and the insulator 524 function as a second gate insulating film.

[0165] Here, the insulator 524 in contact with the oxide 530 has more oxygen than the stoichiometric composition. It is preferable to use an insulator containing oxygen. The oxygen is released from the film by heating. In this specification and elsewhere, the oxygen released by heating may be referred to as "excess oxygen." That is, a region containing excess oxygen (also called an "excess oxygen region") is formed in the insulator 524. It is preferable that the insulator containing such excess oxygen is in contact with the oxide 530. By providing the oxide 530, oxygen vacancies (V O :oxygen vacancy and This can reduce the oxidation (also referred to as oxidation) and improve the reliability of the transistor 500. When hydrogen enters the oxygen vacancy in the substance 530, the defect (hereinafter referred to as V O It may be called H. ) can act as a donor, generating electrons as carriers. The oxygen atom may bond with the metal atom to generate electrons, which act as carriers. Therefore, a transistor using an oxide semiconductor containing a large amount of hydrogen has a normally-on characteristic. In addition, hydrogen in oxide semiconductors tends to move due to stresses such as heat and electric fields. Therefore, if an oxide semiconductor contains a large amount of hydrogen, the reliability of the transistor will decrease. In one embodiment of the present invention, V in the oxide 530 O Reduce H as much as possible and It is preferable to make it pure or substantially pure with high purity. O H is low enough To obtain a reduced oxide semiconductor, impurities such as moisture and hydrogen are removed from the oxide semiconductor. (This is also called "dehydration" or "dehydrogenation treatment"), and supplying oxygen to the oxide semiconductor. It is important to compensate for the oxygen deficiency (also called "oxygenation treatment"). O H etc. By using an oxide semiconductor with a sufficiently reduced content of impurities in the channel formation region of a transistor, , and stable electrical properties can be imparted.

[0166] As an insulator having an excess oxygen region, specifically, an oxide film in which some oxygen is released by heating is used. It is preferable to use a material that releases oxygen when heated. rml Desorption Spectroscopy analysis, converted to oxygen atoms The amount of oxygen released is 1.0×10 18 atoms / cm 3 or more, preferably 1.0 x 1 0 19 atoms / cm 3 More preferably, 2.0 × 10 19 atoms / cm 3 or more, or 3.0 x 10 20 atoms / cm 3 The oxide film is as above. The surface temperature of the film during the TDS analysis is 100°C or higher and 700°C or lower. The temperature range is preferably from 0°C to 400°C.

[0167] In addition, the insulator having the excess oxygen region is brought into contact with the oxide 530 and then subjected to heat treatment. One or more of the following may be performed: microwave processing, RF processing, or the like. By this, water or hydrogen in the oxide 530 can be removed. In 30, a reaction occurs in which the VoH bond is broken, in other words, "V O H→Vo+H This reaction occurs, and some of the hydrogen generated is dehydrogenated. The oxide 530 or the insulator adjacent to the oxide 530 is removed by combining with the element to form H2O. In addition, some of the hydrogen may be gettered by the conductor 542a or the conductor 542b. It may be pinged.

[0168] The microwave treatment may be carried out using, for example, an apparatus having a power source for generating high-density plasma, Alternatively, it is preferable to use an apparatus having a power source for applying RF to the substrate side. By using a gas containing oxygen and high density plasma, high density oxygen radicals are generated. By applying RF to the substrate side, the oxide generated by the high-density plasma can be The atomic radicals can be efficiently introduced into the oxide 530 or into the insulator in the vicinity of the oxide 530. The microwave treatment can be carried out at a pressure of 133 Pa or more, preferably 200 Pa or more. The pressure may be a or more, more preferably 400 Pa or more. The gas introduced into the device is, for example, oxygen and argon, and the oxygen flow ratio (O2 / The gas is preferably heated at a concentration of (O2 + Ar) of 50% or less, preferably 10% or more and 30% or less.

[0169] In addition, during the manufacturing process of the transistor 500, when the surface of the oxide 530 is exposed, The heat treatment is preferably performed at a temperature of 100° C. or higher and 450° C. or lower. More preferably, the temperature is 350° C. or higher and 400° C. or lower. or an inert gas atmosphere, or an oxidizing gas of 10 ppm or more, 1% or more, or 1 For example, it is preferable to carry out the heat treatment in an oxygen atmosphere. By this, oxygen is supplied to the oxide 530, and oxygen vacancies (V O ) can be reduced. The heat treatment may be carried out under reduced pressure or in an atmosphere of nitrogen gas or inert gas. After heat treatment in an oxidizing gas atmosphere, 10ppm of oxidizing gas was added to compensate for the oxygen that was removed. The oxidation may be carried out in an atmosphere containing 1% or more, 1% or more, or 10% or more. After heat treatment in an atmosphere containing 10 ppm or more, 1% or more, or 10% or more, The heat treatment may be performed in a nitrogen gas or inert gas atmosphere.

[0170] By subjecting the oxide 530 to oxygen addition treatment, oxygen vacancies in the oxide 530 are filled with oxygen. In other words, it promotes the reaction "Vo + O → null" Furthermore, the supplied oxygen reacts with the hydrogen remaining in the oxide 530. This allows the hydrogen to be removed as H2O (dehydration). The hydrogen remaining in 530 recombines with the oxygen vacancy and V O By suppressing the formation of H This can be done.

[0171] Also, if the insulator 524 has an excess oxygen region, the insulator 522 may be oxygen-resistant (e.g., It has the function of suppressing the diffusion of oxygen (element atoms, oxygen molecules, etc.) (the oxygen mentioned above is less likely to permeate) is preferred.

[0172] The insulator 522 has a function of suppressing the diffusion of oxygen and impurities, and the oxide 530 is effective. The oxygen thus generated does not diffuse to the conductor 503 side, which is preferable. This can prevent the insulator 524 and the oxide 530 from reacting with oxygen.

[0173] The insulator 522 may be, for example, aluminum oxide, hafnium oxide, aluminum and hafnium oxide. oxides containing ammonium (hafnium aluminate), tantalum oxide, zirconium oxide, titanium Lead zirconate titanate (PZT), strontium titanate (SrTiO3), or (B Insulators containing so-called high-k materials such as a,Sr)TiO3 (BST) are deposited as single layers or As transistors become smaller and more highly integrated, Thinning the gate insulating film can cause problems such as leakage current. By using high-k materials as insulators that function as a transistor, the physical thickness can be maintained. This makes it possible to reduce the gate potential during start operation.

[0174] In particular, it has the function of suppressing the diffusion of impurities and oxygen (the oxygen is difficult to penetrate) ) Insulators containing oxides of one or both of aluminum and hafnium, which are insulating materials It is recommended to use an insulator containing oxides of either or both aluminum and hafnium. , aluminum oxide, hafnium oxide, oxides containing aluminum and hafnium (hafnium It is preferable to use such a material as the insulator 5. When the insulator 522 is formed, the insulator 522 prevents oxygen from being released from the oxide 530 and prevents the transistor from being formed. It functions as a layer that suppresses the intrusion of impurities such as hydrogen from the periphery of 500 into the oxide 530. .

[0175] Alternatively, for example, aluminum oxide, bismuth oxide, or germanium oxide may be added to these insulators. Niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, Alternatively, zirconium oxide may be added to these insulators, or these insulators may be nitrided. Silicon oxide, silicon oxynitride, or silicon nitride may be stacked on the insulator.

[0176] 13A and 13B, the second layer is a three-layer laminate. As the gate insulating film of the second gate electrode, the insulator 522 and the insulator 524 are shown. The gate insulating film may have a single layer, two layers, or a laminated structure of four or more layers. The laminated structure is not limited to a laminated structure made of the same material, but may be a laminated structure made of different materials.

[0177] The transistor 500 has an oxide 530 including a channel formation region, which functions as an oxide semiconductor. For example, the oxide 530 is an In-M-Zn oxide (element M is aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, Titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium , neodymium, hafnium, tantalum, tungsten, magnesium, etc. It is preferable to use a metal oxide such as one or more metal oxides.

[0178] The metal oxide that functions as an oxide semiconductor may be formed by a sputtering method. Alternatively, the ALD (Atomic Layer Deposition) method may be used. The metal oxide functioning as an oxide semiconductor will be described in detail in another embodiment. do.

[0179] In addition, the metal oxide that functions as a channel formation region in the oxide 530 is a band gap metal oxide. It is preferable to use a material with a gap of 2 eV or more, preferably 2.5 eV or more. By using metal oxides with a wide band gap, the off-state current of transistors can be reduced. It is possible.

[0180] The oxide 530 has the oxide 530a under the oxide 530b, so that the oxide 530 is thicker than the oxide 530a. This can suppress the diffusion of impurities from the underlying structure into the oxide 530b. Cut.

[0181] The oxide 530 has a laminated structure of a plurality of oxide layers each having a different atomic ratio of each metal atom. Specifically, in the metal oxide used for the oxide 530a, the constituent elements are preferably The atomic ratio of element M in the oxide 530b is It is preferable that the atomic ratio of the metal oxide used for the oxide 530a is larger than that of the element M. In the oxide 530b, the atomic ratio of the element M to In is It is preferable that the atomic ratio of element M to In is larger than that of element M. In the metal oxide used, the atomic ratio of In to the element M is It is preferable that the atomic ratio of In to the element M in the metal oxide is larger than that of In.

[0182] In addition, the energy of the conduction band minimum of the oxide 530a is smaller than that of the oxide 530b. In other words, the electron affinity of the oxide 530a is preferably higher than the energy. , preferably smaller than the electron affinity of oxide 530b.

[0183] Here, at the junction between the oxide 530a and the oxide 530b, the energy of the conduction band minimum is In other words, the junction of oxide 530a and oxide 530b The energy level of the conduction band minimum in this region is said to change continuously or to form a continuous junction. To achieve this, the oxide 530a and the oxide 530b must be at the interface between them. This can reduce the defect level density of the mixed layer formed by the above process.

[0184] Specifically, the oxide 530a and the oxide 530b have a common element other than oxygen (main component). By using a mixed layer with a low defect level density, for example, an oxide When 530b is an In-Ga-Zn oxide, the oxide 530a is an In-Ga-Zn oxide. It is preferable to use gallium oxide, Ga-Zn oxide, gallium oxide, etc.

[0185] At this time, the main path of the carriers is the oxide 530b. This reduces the defect state density at the interface between the oxide 530a and the oxide 530b. Therefore, the influence of interface scattering on carrier conduction is reduced, and the The transistor 500 can obtain a high on-state current.

[0186] On the oxide 530b, a conductor 542a is formed, which functions as a source electrode and a drain electrode. The conductor 542a and the conductor 542b are provided as follows: , aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum , tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconia Sodium, beryllium, indium, ruthenium, iridium, strontium, lanthanum or an alloy containing the above metal elements, or It is preferable to use a combination of alloys, for example, tantalum nitride, titanium nitride, tantalum titanium and aluminum nitrides, tantalum and aluminum nitrides, Ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum It is preferable to use oxides containing nickel. , nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide Ruthenium, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel Oxides containing oxygen are conductive materials that are resistant to oxidation or that maintain conductivity even after absorbing oxygen. Furthermore, metal nitride films such as tantalum nitride are preferable because they can be easily etched by hydrogen or oxygen. It is preferable because it has a barrier property against elements.

[0187] In addition, although the conductor 542a and the conductor 542b are shown as having a single layer configuration in FIG. Alternatively, a laminated structure of two or more layers may be used. For example, a tantalum nitride film and a tungsten film may be laminated. Alternatively, a titanium film and an aluminum film may be stacked. Two-layer structure with an aluminum film laminated on a copper-magnesium-aluminum alloy film, and a copper film on a copper-magnesium-aluminum alloy film Two-layer structure with a copper film on a titanium film, two-layer structure with a copper film on a tungsten film A two-layer structure may also be used.

[0188] Also, a titanium film or titanium nitride film and an aluminum film overlaid on the titanium film or titanium nitride film are used. A titanium film or a copper film is laminated, and a titanium film or a titanium nitride film is further formed on the aluminum film or a copper film. Three-layer structure: a molybdenum film or molybdenum nitride film and a molybdenum film or molybdenum nitride film. An aluminum film or copper film is laminated on top of the molybdenum film, and then a molybdenum film or The molybdenum nitride film may be formed as a three-layer structure. A transparent conductive material containing zinc oxide may also be used.

[0189] As shown in FIG. 13A, the oxide 530 and the conductor 542a (conductor 542b) At the interface and its vicinity, a region 543a and a region 543b are formed as low resistance regions. In this case, the region 543a functions as either a source region or a drain region. The region 543b functions as the other of the source region and the drain region. A channel forming region is formed in the region sandwiched between region 543a and region 543b.

[0190] By providing the conductor 542a (conductor 542b) so as to be in contact with the oxide 530, The oxygen concentration in the region 543a (region 543b) may decrease. The metal contained in the conductor 542a (conductor 542b) and the oxide 530 are mixed in the region 543b. In such a case, a metal compound layer containing the metal compound may be formed in the region 543a (region The carrier density in the region 543a (region 543b) increases, and the region 543a (region 543b) becomes a low resistance region. do.

[0191] The insulator 544 is provided to cover the conductor 542a and the conductor 542b. The insulator 544 prevents oxidation of the oxide 542a and the conductor 542b. 530 and may be provided to be in contact with the insulator 524.

[0192] Insulator 544 includes hafnium, aluminum, gallium, yttrium, and zirconium. Aluminum, tungsten, titanium, tantalum, nickel, germanium, neodymium, lanthanum, or a metal oxide containing one or more selected from magnesium, etc. The insulator 544 may be made of silicon nitride oxide, silicon nitride, or the like. can also be used.

[0193] In particular, the insulator 544 may be an oxide of aluminum or hafnium, or both. Insulators containing aluminum oxide, hafnium oxide, aluminum, and hafnium It is preferable to use oxides containing hafnium (hafnium aluminate). Hafnium aluminate has higher heat resistance than hafnium oxide. This is preferable because it is difficult to crystallize during the heat treatment. 542b is a material that is oxidation-resistant, or the conductivity does not decrease significantly even when it absorbs oxygen. In the case of a material, the insulator 544 is not an essential component. , can be designed appropriately.

[0194] By providing the insulator 544, impurities such as water and hydrogen contained in the insulator 580 are converted into acids. In addition, the excess of the insulator 580 can be prevented from diffusing into the oxide 530b. This can prevent the conductors 542a and 542b from being oxidized by oxygen.

[0195] The insulator 545 functions as a first gate insulating film. Similar to 524, it is made using an insulator that contains excess oxygen and releases oxygen when heated. It is preferable to form

[0196] Specifically, silicon oxide having excess oxygen, silicon oxynitride, silicon nitride oxide, and nitride silicon dioxide, fluorine-doped silicon dioxide, carbon-doped silicon dioxide, carbon, and Silicon oxide doped with nitrogen and silicon oxide having vacancies can be used. Silicon oxide and silicon oxynitride are preferred because they are stable to heat.

[0197] By providing an insulator containing excess oxygen as the insulator 545, the oxide In addition, oxygen can be effectively supplied to the channel forming region of the insulator 530b. As in 24, the concentration of impurities such as water or hydrogen in the insulator 545 is reduced. It is preferable that the thickness of the insulator 545 is 1 nm or more and 20 nm or less. The microwave treatment described above may be performed before and / or after the formation of the insulator 545. stomach.

[0198] In addition, in order to efficiently supply excess oxygen contained in the insulator 545 to the oxide 530, A metal oxide may be provided between the body 545 and the conductor 560. The metal oxide may be an insulator. It is preferable to suppress the diffusion of oxygen from 545 to the conductor 560. The metal oxide prevents excess oxygen from diffusing from the insulator 545 to the conductor 560. In other words, it is possible to suppress a decrease in the amount of excess oxygen supplied to the oxide 530. This can prevent the conductor 560 from being oxidized by excess oxygen. Any material that can be used for the insulator 544 may be used.

[0199] Note that the insulator 545 may have a stacked structure similar to the second gate insulating film. As the miniaturization and high integration of devices progresses, the gate insulating film becomes thinner, which reduces leakage current and other problems. Therefore, the insulator that functions as the gate insulating film is made of high-k material. By using a laminated structure of a material that is thermally stable and a material that is thermally stable, the thickness of the material is maintained while the It is possible to reduce the gate potential during transistor operation. It may have a laminated structure.

[0200] The conductor 560 functioning as the first gate electrode has a two-layer structure in FIGS. 13A and 13B. However, it may have a single layer structure or a laminated structure of three or more layers.

[0201] The conductor 560a is a hydrogen atom, a hydrogen molecule, a water molecule, a nitrogen atom, a nitrogen molecule, a nitrogen oxide molecule ( Conductive material with the function of suppressing the diffusion of impurities such as N2O, NO, NO2, etc., copper atoms, etc. It is preferable to use a material containing at least oxygen (for example, oxygen atoms, oxygen molecules, etc.). It is preferable to use a conductive material that has the function of suppressing the diffusion of the conductor 56. Oa has the function of suppressing oxygen diffusion, so the oxygen contained in the insulator 545 This can prevent the conductor 560b from being oxidized and the conductivity from decreasing. Examples of conductive materials that have the function of suppressing this include tantalum, tantalum nitride, and ruthenium. It is preferable to use ruthenium or ruthenium oxide as the conductor 560a. In this case, an oxide semiconductor that can be used for the oxide 530 can be used. By forming a film of conductor 560b by sputtering, the electrical resistance value of conductor 560a is reduced. This is called an OC (Oxide Conductor) electrode. This can be done.

[0202] The conductor 560b is a conductive material mainly composed of tungsten, copper, or aluminum. In addition, since the conductor 560b also functions as a wiring, It is preferable to use a highly conductive material, such as tungsten, copper, or aluminum. The conductor 560b can be made of a conductive material containing silicon as a main component. For example, it may be a laminated structure of titanium or titanium nitride and the above conductive material. stomach.

[0203] The insulator 580 is provided on the conductor 542a and the conductor 542b via the insulator 544. Preferably, the insulator 580 has an excess oxygen region. For example, the insulator 58 0, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, fluorine silicon oxide doped with carbon, silicon oxide doped with carbon, and acid doped with nitrogen. It is particularly preferable that the insulating layer 100 has a silicon oxide, a silicon oxide having pores, or a resin. Silicon oxide and silicon oxynitride are preferred because they are thermally stable. Silicon oxide and silicon oxide with vacancies easily form excess oxygen regions in later processes. This is preferable because it is possible to

[0204] The insulator 580 preferably has an excess oxygen region. By providing the insulator 580, oxygen in the insulator 580 is efficiently supplied to the oxide 530. It should be noted that the concentration of impurities such as water or hydrogen in the insulator 580 is reduced. It is preferable.

[0205] The opening in the insulator 580 is formed to overlap the region between the conductor 542a and the conductor 542b. As a result, the conductor 560 is inserted through the opening in the insulator 580 and the conductor 542a and the conductor 542b. It is formed so as to be embedded in the region sandwiched between 542b.

[0206] In miniaturizing semiconductor devices, it is required to shorten the gate length. Therefore, the thickness of the conductor 560 must be increased. As a result, the conductor 560 can have a shape with a high aspect ratio. In order to embed the conductor 560 in the opening of the insulator 580, the conductor 560 is formed to have an aspect ratio Even if the shape is high, the conductor 560 can be formed without collapsing during the process. do.

[0207] The insulator 574 is connected to the top surface of the insulator 580, the top surface of the conductor 560, and the top surface of the insulator 545. The insulator 574 is preferably provided in contact with the , insulator 545, and insulator 580. From this excess oxygen region, oxygen can be supplied into the oxide 530 .

[0208] For example, the insulator 574 may be hafnium, aluminum, gallium, yttrium, or di zinc, tungsten, titanium, tantalum, nickel, germanium, or magnesium Metal oxides containing one or more metals selected from the group consisting of sodium, do.

[0209] In particular, aluminum oxide has a high barrier property and is a thin film of 0.5 nm to 3.0 nm. Therefore, the diffusion of hydrogen and nitrogen can be suppressed even if the sputtering method is used. The aluminum oxide film formed by this method is both an oxygen source and a barrier to impurities such as hydrogen. It can also function as a membrane.

[0210] In addition, it is preferable to provide an insulator 581 that functions as an interlayer film over the insulator 574. The insulator 581, like the insulator 524, has a low impurity concentration such as water or hydrogen. It is preferably reduced.

[0211] Also, openings formed in the insulators 581, 574, 580, and 544 Conductor 540a and conductor 540b are placed in the mouth. The conductors 540a and 540b are provided opposite each other with the conductor 560 in between. b has the same configuration as conductor 546 and conductor 548 described later.

[0212] An insulator 582 is provided on the insulator 581. The insulator 582 is resistant to oxygen and hydrogen. Therefore, the insulator 582 is preferably made of an insulating material having a barrier property. The insulator 582 may be made of a material similar to that of the insulator 514. For example, the insulator 582 may be made of aluminum oxide. It is preferable to use metal oxides such as tantalum oxide, hafnium oxide, and the like.

[0213] In particular, aluminum oxide is a material that can absorb oxygen and hydrogen, which can cause fluctuations in the electrical characteristics of transistors. Therefore, it has a high blocking effect that prevents impurities such as acid and moisture from passing through the membrane. Aluminum oxide is resistant to hydrogen, moisture, etc. during and after the transistor manufacturing process. It is possible to prevent impurities from being mixed into the transistor 500. This can suppress the release of oxygen from the oxide that makes up the transistor. Suitable for use as a protective film against 500.

[0214] An insulator 586 is provided on the insulator 582. The insulator 586 is 20 can be used. In addition, these insulators have a relatively low dielectric constant. By applying the material, it is possible to reduce the parasitic capacitance that occurs between wiring. For example, The body 586 can be a silicon oxide film, a silicon oxynitride film, or the like.

[0215] Also, the insulator 522, the insulator 524, the insulator 544, the insulator 580, the insulator 574, the insulator The conductor 546 and the conductor 548 are connected to the insulator 581, the insulator 582, and the insulator 586. etc. are embedded.

[0216] The conductor 546 and the conductor 548 are connected to the capacitor 600, the transistor 500, or the transistor 500. The conductor 546 functions as a plug or wiring that connects to the transistor 550. The conductor 548 is formed using the same material as the conductor 428 and the conductor 430. It is possible.

[0217] After the transistor 500 is formed, an opening is formed to surround the transistor 500. An insulator having high barrier properties against hydrogen or water may be formed so as to cover the opening. By encasing the transistor 500 in the insulator with high barrier properties, moisture and It is possible to prevent the intrusion of hydrogen and oxygen. Alternatively, the transistor may be wrapped in an insulator that has a high barrier property against hydrogen or water. When forming an opening to surround the transistor 500, for example, the insulator 522 or the insulator 5 14, and the burr 522 or 514 is in contact with the insulator 522 or 514. If a highly insulating material is formed, it can be used as part of the manufacturing process of the transistor 500. In addition, examples of insulators with high barrier properties against hydrogen or water include: A material similar to that of the insulator 522 or the insulator 514 may be used.

[0218] Next, a capacitor 600 is provided above the transistor 500. 00 has a conductor 610, a conductor 620, and an insulator 630.

[0219] Moreover, a conductor 612 may be provided on the conductor 546 and the conductor 548. 12 has a function as a plug or wiring that connects to the transistor 500. The conductor 610 functions as an electrode of the capacitor 600. The conductors 610 can be formed at the same time.

[0220] The conductor 612 and the conductor 610 may be made of molybdenum, titanium, tantalum, or tungsten. a metal film containing an element selected from aluminum, copper, chromium, neodymium, and scandium; Or a metal nitride film containing the above-mentioned elements (tantalum nitride film, titanium nitride film, molybdenum nitride film, etc.) Indium tin oxide (ITO) or tungsten nitride (Tungsten nitride) can be used. Indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide oxide, indium oxide with titanium oxide, indium tin oxide with titanium oxide, Conductive materials such as indium zinc oxide and indium tin oxide with added silicon oxide are used You can also do this.

[0221] In this embodiment, the conductor 612 and the conductor 610 are shown as having a single-layer structure. For example, a conductive material having a barrier property and a conductive material having a barrier property may be laminated. Conductors with barrier properties are placed between the highly conductive conductors and those with high conductivity. A highly adhesive conductor may be formed.

[0222] The conductor 620 is provided so as to overlap with the conductor 610 with the insulator 630 interposed therebetween. The conductor 620 is made of a conductive material such as a metal material, an alloy material, or a metal oxide material. High-melting-point materials such as tungsten and molybdenum, which have both heat resistance and electrical conductivity, are used. It is preferable to use tungsten, and it is particularly preferable to use tungsten. When forming the layer simultaneously with other components, low-resistance metal materials such as Cu (copper) and Al (aluminum) are used. It is best to use a

[0223] An insulator 640 is provided on the conductor 620 and the insulator 630. The insulator 640 can be formed using a material similar to that of the insulator 420. It may also function as a planarizing film that covers the underlying unevenness.

[0224] By using this structure, a semiconductor device including a transistor having an oxide semiconductor This allows for miniaturization or high integration.

[0225] The configurations, structures, methods, and the like shown in this embodiment may be different from the configurations, structures, methods, and the like shown in other embodiments. It can be used in combination with other methods as appropriate. [Explanation of symbols]

[0226] 10: living body, 100: semiconductor device, 110: communication unit, 111: RF circuit, 112: resonant circuit circuit, 113: power supply circuit, 114: clock generation circuit, 115: demodulation circuit, 116: modulation circuit 117: information processing circuit, 120: calculation unit, 121: calculation circuit, 122: memory circuit, 1 30: control unit, 140: storage unit, 150: sensor unit, 190: covering material

Claims

[Claim 1] A semiconductor device that can be implanted in a living body, The device includes a communication unit, a control unit, a storage unit, a calculation unit, and a sensor unit, the storage unit has a function of storing identification information, The calculation unit has a function of storing first information; a function of generating third information using the first information and the second information supplied from the sensor unit, The control unit In response to a signal input via the communication unit, One or both of the identification information and the third information, having a function of outputting the information to the outside via the communication unit; The computing unit is a semiconductor device including a transistor having an oxide semiconductor in a channel formation region.

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