Semiconductor device

Abstract

To provide a semiconductor device with a novel structure.SOLUTION: A semiconductor device has a current voltage conversion unit, a current switching unit, a voltage current conversion unit, and a control unit. The current switching unit has a first transistor. The voltage current conversion unit has a second transistor. The control unit has a third transistor. The first transistor has an oxide semiconductor in a channel formation region. The second transistor has a nitride semiconductor in a channel formation region. The third transistor has silicon in a channel formation region. The first transistor is provided on a first substrate. The second transistor and the third transistor are provided at a second substrate.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. is a process, machine, manufacture, or composition of matter. This concerns the

[0003] In this specification and the like, a semiconductor device is a device that can function by utilizing semiconductor characteristics. Therefore, it refers to semiconductor elements such as transistors and diodes, and The circuit including the semiconductor device is also used in display devices, light-emitting devices, lighting devices, electro-optical devices, imaging devices, etc. Devices, communication devices, and electronic devices may contain semiconductor elements and semiconductor circuits. display devices, light-emitting devices, lighting devices, electro-optical devices, imaging devices, communication devices, and electronic devices Also, these may be called semiconductor devices. [Background technology]

[0004] As a switching device for high-speed operation, high-mobility semiconductors such as gallium nitride are being developed. The transistors used are nitrides of group 13 elements such as gallium nitride (GaN). A transistor having GaN in the channel formation region (hereinafter referred to as a GaN transistor) It operates in normal on mode.

[0005] GaN transistors are transistors that contain different semiconductor materials in order to achieve high performance. For example, a transistor (Si transistor) that has silicon (Si) in the channel formation region. For example, in Patent Document 1, GaN transistors are combined with Si transistors to produce enhancement mode (normal A switching device capable of operating in a low-voltage (low-voltage) regime is disclosed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-222360 Summary of the Invention [Problem to be solved by the invention]

[0007] As communication speeds and other factors increase, the switching speed of switching devices also increases. In the mixer circuits used in the transmission and reception circuits of communication devices, signals with different frequencies are mixed. A multiplied signal is generated.

[0008] A mixer circuit (also called an active mixer) using a Gilbert cell (also called a Gilbert circuit) The amplifier consists of a current-voltage (I / V) converter, a current switch, and a voltage-current (V / I) converter (amplifier). The transistors in the voltage-to-current converter are designed to allow a large current to flow. GaN transistors are used because they allow current to flow easily when turned off. Therefore, it is a normally-on transistor in which current does not easily flow when it is off. By applying a Si transistor that turns off to the current switch section, the current that flows when the transistor is off (leak current) is suppressed.

[0009] However, in high-temperature environments, both GaN and Si transistors suffer from leakage current. The increase in leakage current may lead to an increase in power consumption. Increased leakage current in switching devices may cause malfunctions. be.

[0010] An object of one embodiment of the present invention is to provide a semiconductor device or the like having a novel structure. Another object is to provide a semiconductor device or the like that is excellent in reducing power consumption. One of the objects of the present invention is to provide a semiconductor device or the like with excellent operational reliability.

[0011] The description of these problems does not preclude the existence of other problems. One embodiment does not necessarily solve all of these problems. Problems other than these may be solved by the specification. It is obvious from the description, drawings, claims, etc. It is possible to extract other issues from the descriptions in the sections. [Means for solving the problem]

[0012] One aspect of the present invention is a power supply circuit including a current-voltage converter, a current switch, and a voltage-current converter. The current switch unit has a first transistor, and the voltage-to-current converter unit has a second transistor. the first transistor has an oxide semiconductor in a channel formation region; The first transistor has a nitride semiconductor in a channel forming region, and the second transistor has The semiconductor device is provided on the upper layer of the layer on which the semiconductor device is provided.

[0013] One aspect of the present invention is a power supply including a current-voltage converter, a current switch, a voltage-current converter, and a control unit. and the current switch unit has a first transistor, and the voltage-current converter unit has a second transistor. the control section has a third transistor, and the first transistor has a channel type the first transistor has an oxide semiconductor in a channel formation region, and the second transistor has a nitride semiconductor in a channel formation region. the third transistor has silicon in a channel formation region, and the first transistor a semiconductor device provided in a layer above the layer in which the second transistor and the third transistor are provided; It is a location.

[0014] One aspect of the present invention is a power supply including a current-voltage converter, a current switch, a voltage-current converter, and a control unit. and the current switch unit has a first transistor, and the voltage-current converter unit has a second transistor. the control section has a third transistor, and the first transistor has a channel type the first transistor has an oxide semiconductor in a channel formation region, and the second transistor has a nitride semiconductor in a channel formation region. the third transistor has silicon in a channel formation region, and the first transistor The first transistor is provided on a first substrate, and the second and third transistors are provided on a second substrate. By bonding the first substrate and the second substrate together, the first to third transistors are formed. The semiconductor device is electrically connected to the

[0015] In one embodiment of the present invention, the current-voltage converter preferably includes a resistor element. stomach.

[0016] In one aspect of the present invention, the voltage-current converter includes a fourth transistor and an inductor. The source or drain of the fourth transistor is electrically connected to the first terminal of the inductor. and the second terminal of the inductor is electrically connected to the gate of the second transistor; The fourth transistor is preferably a semiconductor device having an oxide semiconductor in a channel formation region. .

[0017] In one embodiment of the present invention, the frequency of the signal applied to the gate of the first transistor is Preferably, the semiconductor device has a frequency greater than the frequency of the signal applied to the gate of the transistor.

[0018] In one embodiment of the present invention, the oxide semiconductor is a semiconductor containing In, Ga, and Zn. The device is preferred.

[0019] In one aspect of the present invention, the nitride semiconductor is preferably a semiconductor device containing Ga.

[0020] Other aspects of the present invention will be described in the following embodiments and and as described in the drawings. [Effects of the Invention]

[0021] One embodiment of the present invention can provide a semiconductor device or the like with a novel structure. It is possible to provide a semiconductor device or the like that is excellent in power consumption or that is excellent in operational reliability. Therefore, it is possible to provide a semiconductor device having such a structure.

[0022] 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. The above is self-evident from the description, drawings, claims, etc. From the above descriptions, it is possible to extract other effects. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a semiconductor device. [Figure 2] 2A and 2B are diagrams illustrating an example of the configuration of a semiconductor device. [Figure 3] 3A and 3B are diagrams illustrating an example of the configuration of a semiconductor device. [Figure 4] 4A and 4B are diagrams 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 a configuration example of a semiconductor device. [Figure 7] 7A and 7B are diagrams illustrating an example of the configuration of a semiconductor device. [Figure 8] 8A to 8C are diagrams illustrating an example of the configuration of a semiconductor device. [Figure 9] FIG. 9 is a diagram illustrating an example of the configuration of a wireless communication device. [Figure 10] FIG. 10 is a diagram illustrating an example of the configuration of a wireless communication device. [Figure 11] FIG. 11 is a diagram illustrating a configuration example of a semiconductor device. [Figure 12] 12A to 12C are diagrams showing examples of the configuration of a transistor. [Figure 13] 13A to 13C are diagrams showing examples of the configuration of a transistor. [Figure 14] 14A to 14C are diagrams showing examples of the configuration of a transistor. [Figure 15] Figure 15A is a diagram explaining the classification of IGZO crystal structures, Figure 15B is a diagram explaining the XRD spectrum of a CAAC-IGZO film, and Figure 15C is a diagram explaining the electron microbeam diffraction pattern of a CAAC-IGZO film. [Figure 16] Figure 16A is a top view of a semiconductor wafer, and Figure 16B is an enlarged view of a chip. [Figure 17] Fig. 17A is a flowchart illustrating an example of a manufacturing process for an electronic component, and Fig. 17B is a schematic perspective view of the electronic component. [Figure 18] FIG. 18 is a diagram illustrating an example of an electronic device. [Figure 19]19A to 19F are diagrams showing an example of an electronic device. [Figure 20] Figure 20 shows the hierarchical structure of IoT networks and trends in required specifications. [Figure 21] Figure 21 is an image diagram of factory automation. DETAILED DESCRIPTION OF THE INVENTION

[0024] The following describes an embodiment of the present invention. However, one embodiment of the present invention is not limited to the following description. The present invention is not limited to the above, and various modifications and variations in form and detail may be made without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that the present invention can be modified as follows. However, the present invention should not be construed as being limited to the description of the following embodiments.

[0025] In this specification, the ordinal numbers "first," "second," and "third" refer to the constituent elements. The numbers are added to avoid confusion and do not limit the number of components. The order of the components is not limited. The element referred to as "first" in one embodiment may be used in other embodiments or in the claims. In addition, for example, the second component may be the component referred to as "second" in the specification. A component referred to as "first" in one embodiment may be used in other embodiments, or It may be omitted in the claims.

[0026] In the drawings, elements that are the same or have similar functions, elements that are made of the same material, or In some cases, elements formed at the same time may be given the same reference numerals, and repeated explanations thereof will be omitted. This may occur.

[0027] In this specification, for example, the power supply potential VDD is abbreviated as potential VDD, VDD, etc. This may be due to the presence of other components (e.g., signals, voltages, circuits, elements, electrodes, wiring, etc.). The same applies to (etc.).

[0028] Also, when the same reference numeral is used for multiple elements, particularly when it is necessary to distinguish between them, The code is followed by an identifying code such as "_1", "_2", "[n]", or "[m,n]". For example, the second wiring GL is written as wiring GL[2].

[0029] (Embodiment 1) A semiconductor device according to one embodiment of the present invention will be described with reference to the drawings. One example is a mixer circuit (active type) using a Gilbert cell (also called a Gilbert circuit). 1 is a diagram illustrating a semiconductor device 100 that functions as a mixer. The device 100 includes a current-voltage converter 101, a current switch 102, and a voltage-current converter 103 (amplifier). It has a width portion.

[0030] The current-voltage converter 101 converts the flowing current I IF is converted to a voltage to produce the signal V IF Output as The current-voltage conversion unit 101 can be configured with a resistor element or the like. The element can be made of a semiconductor layer such as silicon. It is sometimes called a current-voltage conversion circuit, or simply a circuit.

[0031] The current switch 102 switches the current flowing between the current-voltage converter 101 and the voltage-current converter 103. It functions as a switch to switch whether or not the current flowing through the circuit is cut off in response to the signal LO. O is a signal of an arbitrary frequency output from an oscillator circuit or the like. By cutting off the current in response to the signal LO, the signal V RF of The signal V is the frequency converted signal. IF can be output from the current-voltage conversion unit 101. The current switch unit 102 may be referred to as a current switch circuit or simply as a circuit. do.

[0032] The current switch unit 102 functions as a switch that can cut off current. The transistor 111 includes a semiconductor layer 11 having a channel formation region. 2 is an oxide semiconductor (also called a metal oxide) An OS transistor is preferably an n-channel transistor. The operation of this transistor will be explained.

[0033] Since the band gap of oxide semiconductors is 2.5 eV or more, OS transistors can be fabricated with extremely small As an example, when the voltage between the source and drain is 3.5V and at room temperature (25°C), The off-state current per 1 μm of channel width is 1×10 -20 Less than A, 1 x 10 -22 Less than A or 1 x 10 -24 That is, the current switch unit 10 2 can minimize the leakage current that flows when the device is off.

[0034] Highly integrated semiconductor devices may generate heat due to the operation of the circuits. When the temperature of a transistor rises due to heat generation, the characteristics of the transistor change. This can cause changes in field-effect mobility and a decrease in operating frequency. However, because it has higher heat resistance than Si transistors, changes in field-effect mobility due to temperature changes do not occur. Furthermore, OS transistors are less susceptible to temperature fluctuations and a drop in operating frequency. Even if the gate-source voltage is increased, the drain current increases exponentially with the gate-source voltage. Therefore, by using OS transistors, it is possible to maintain the performance even in high temperature environments. This allows for stable operation.

[0035] Oxide semiconductors used in OS transistors include Zn oxide and Zn-Sn oxide. , Ga-Sn oxide, In-Ga oxide, In-Zn oxide, In-M-Zn oxide (M The elements are Ti, Ga, Y, Zr, La, Ce, Nd, Sn or Hf. When an oxide semiconductor using Ga as an oxide semiconductor is used for an OS transistor, the ratio of the elements is adjusted. By using this method, a transistor having excellent electrical properties such as field-effect mobility can be obtained. In addition, oxides containing indium and zinc may be used in combination with aluminum, gallium, yttrium, and the like. Sodium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, gel Al, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, Contains one or more of the following: tantalum, tungsten, magnesium, etc. That's fine.

[0036] In order to improve the reliability and electrical characteristics of OS transistors, oxide semiconductors are applied to the semiconductor layer. The body is an oxide semiconductor with crystalline parts such as CAAC-OS, CAC-OS, and nc-OS. CAAC-OS is a c-axis-aligned cryst CAC-OS is an abbreviation for alline oxide semiconductor. is a cloud-aligned composite oxide semicond nc-OS is an abbreviation of nanocrystalline oxide. It is an abbreviation for e-semiconductor.

[0037] CAAC-OS has a c-axis orientation and multiple nanocrystals are connected in the ab-plane direction. The crystal structure is distorted by the connection of multiple nanocrystals. In the region, the lattice arrangement is changed between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement. Indicates the point where the direction is changing.

[0038] CAC-OS has the function of flowing electrons (or holes) that act as carriers, and the function of discharging the electrons that act as carriers. The function of allowing electrons to flow and the function of not allowing electrons to flow are separated. In other words, CAC-OS can be used as an OS transition. By using it in the channel formation region of a semiconductor, it is possible to achieve both a high on-current and an extremely low off-current. This can be achieved.

[0039] Oxide semiconductors have a large band gap, which makes it difficult for electrons to be excited, and the effective number of holes is high. Due to their large mass, OS transistors are less efficient than general Si transistors. Therefore, for example, avalanche breakdown may not occur easily. This can suppress hot carrier degradation, which is a problem that occurs when the device is turned on. The OS transistor can be driven by the drain voltage.

[0040] OS transistors are accumulation-type transistors that use electrons as majority carriers. , it is shorter than an inversion transistor (typically a Si transistor) having a pn junction. One of the channel effects is the drain-induced barrier loss (DIBL). In other words, OS transistors have a lower power dissipation than Si transistors. Also, it has high resistance to short channel effects.

[0041] OS transistors have high resistance to short channel effects, By using OS transistors, the channel length can be reduced without degrading reliability. The degree of circuit integration can be increased. As the channel length becomes smaller, the drain electric field becomes stronger. However, as mentioned above, OS transistors have a higher avalanche breakdown rate than Si transistors. is less likely to occur.

[0042] In addition, OS transistors have high resistance to short channel effects, making them superior to Si transistors. For example, the channel length and the channel Even for miniaturized transistors with widths of 50 nm or less, a gate insulating film as thick as 10 nm is required. It may be possible to reduce the parasitic capacitance by making the gate insulating film thicker. This allows for faster operation of the circuit. This reduces the leakage current through the gate insulating film, which leads to a reduction in static current consumption.

[0043] As described above, the current switch unit 102 has an OS transistor, and therefore the current that flows when the current switch unit 102 is turned off. In addition, the layer containing the OS transistor can be That is, the current switch unit 102 can be provided on a layer having a current switch. The voltage-current converter 103 is laminated on a layer having transistors constituting the voltage-current converter 101. Therefore, it can be arranged without increasing the circuit area. In other words, the circuit area in which the transistors can be arranged increases, so that the transistors of the current switch unit 102 This increases the amount of current that the transistor can pass.

[0044] The voltage-to-current converter 103 converts the signal V RF is converted to a current, and the current I RF It has the function of Current I RF is a current whose cutoff is controlled by the current switch unit 102. RF teeth , is a signal given from the outside. Signal V RF The frequency of is higher than the frequency of the signal LO. That is, the voltage-current converter 103 converts the high-frequency signal V RF Current I according to RF to flush The voltage-current converter 103 may be a voltage-current converter circuit or simply a It may be called a circuit.

[0045] The voltage-to-current converter 103 converts the signal V RF The current I RF Transistor 1 that conducts The transistor 121 has a semiconductor layer 122 having a channel formation region. A nitride semiconductor containing a group 3 element (such as gallium) is used in the channel formation region. A transistor having a gallium nitride (GaN transistor) is suitable. Hereinafter, GaN is a transistor having a channel forming region. As an example, we will explain a transistor with a GaN channel region. Alternatively, a high mobility transistor other than a nitride semiconductor may be used. Alternatively, a transistor having SiC or the like in a channel forming region may be used.

[0046] When the semiconductor layer 122 is made of GaN, it is preferable to laminate it with AlGaN. AlN has a bandgap approximately twice that of GaN (3.4V). (6.2 eV), which is about four times the electrostatic breakdown field of GaN (3.3 MV / cm) 12MV / cm), and the thermal conductivity is about 1.5 times that of GaN (2W / cmK). It has extremely excellent material properties (W / cmK). N is a preferred material for high-power, high-frequency devices. HEMT (High Electron Mobility Transistor) This allows for higher breakdown voltage operation than HEMTs that use GaN as the channel formation region. At the interface between GaN and AlGaN, a secondary polarization occurs due to the polarization effect between GaN and AlGaN. two dimensional electron gas (2DEG) can be generated, and can be used as a high mobility transistor.

[0047] FIG. 2A is a diagram illustrating a specific configuration example of a semiconductor device 100 according to one embodiment of the present invention. As described in FIG. 1, the semiconductor device 100 includes a current-voltage conversion unit 101, a current switch The circuit has a switch unit 102 and a voltage-current converter unit 103.

[0048] The current-voltage conversion unit 101 includes a resistance element 131A and a resistance element 131B. The switch unit 102 receives the signal LO + Transistor 111A is supplied with signal LO- is given The signal LO has a transistor 111B. - is the signal LO + This is the inverted signal of the signal LO + The signal LO is sometimes referred to as the signal LO. The voltage-current converter 103 converts the signal V RF Transistor 12 is given Transistor 121A is a GaN transistor.

[0049] The semiconductor device 100 receives a signal V RF , signal LO, and signal V according to the frequency of IF Output Signal V IF The frequency of the signal V RF The frequency of the signal LO is f1 and the frequency of the signal LO is f2. By doing so, it is possible to generate a signal with a frequency of (f1-f2) or (f1+f2). In addition, GaN transistors have higher field-effect mobility than OS transistors, so It is preferable that the wave number f1 is set to be larger than the frequency f2. This allows for a wider range of available frequency bands.

[0050] Transistor 111A and transistor 111B shown in FIG. The resistors 121A can be stacked on different layers of the substrate. In the semiconductor device 100 according to one embodiment of the present invention, a layer including a transistor is stacked on a substrate. FIG.

[0051] In the schematic diagram of the semiconductor device 100 shown in FIG. 2B, a substrate 140, a transistor 121 ( Layer 141 having transistor 111 (transistor 111A) , 111B). The layer 142 having the transistor 111 is It is provided on the layer 141 having the transistor 121. That is, the transistor 11 The OS transistor 1 can be provided in a layer above the layer in which the transistor 121 is provided. Since the circuit area where the transistors can be arranged increases, the current flowing through the transistors of the current switch unit 102 The amount can be increased.

[0052] The substrate 140 is a SIMOX (Separation by Implantation) A substrate having silicon such as an Oxygen (Oxygen) substrate or an SOI substrate can be used. Transistors with silicon in the channel formation region on the substrate or in the plate (Si transistors) This is preferable because it is possible to provide a

[0053] The signals LO and 103 are supplied to the current switch unit 102 and the voltage-current converter unit 103 shown in FIG. signal V RF The configuration is such that the signal is output from the control unit. Please refer to the following for explanation.

[0054] The semiconductor device 100A shown in FIG. 3A includes a control unit 104A in addition to the configuration shown in FIG. The control unit 104A and the control unit 104B correspond to a configuration including the oscillation circuit. It functions as a signal output section for a line, etc.

[0055] The control unit 104A and the control unit 104B are configured to control a bias generator capable of generating a bias voltage. The transistor 131 functions as a synthesis circuit or an oscillation circuit. 1 is preferably a transistor that can form a bias generating circuit or an oscillator circuit. For example, a transistor ( Si transistors are suitable for n-channel and Since a complementary circuit configuration using p-channel and p-channel transistors can be achieved, This is preferable when the control unit 104 is configured as a circuit that functions as a clock circuit or an oscillation circuit. A. Control unit 104B may be called a control circuit or simply a circuit.

[0056] The transistor 131, which is a Si transistor, is stacked on a different layer on the substrate. FIG. 3B shows a semiconductor device 100A according to an embodiment of the present invention. 1 is a diagram for schematically illustrating a layer including a transistor stacked in a semiconductor device.

[0057] In the schematic diagram of the semiconductor device 100A shown in FIG. 3B, the substrate 140 shown in FIG. 2B, the layer In addition to layers 141 and 142, layer 143 having transistor 131 is shown. , and is provided on the layer 141 and the layer 143. That is, the transistor 111 is a transistor It can be provided in a layer above the layer in which the transistor 121 and the transistor 131 are provided. Since the circuit area where the OS transistor can be arranged increases, the transistor of the current switch unit 102 This allows the amount of current the starter can pass to be increased.

[0058] FIG. 4A shows a specific configuration example of a modified example of the semiconductor device 100 described above in FIG. 2A. The semiconductor device 100B shown in FIG. 4A is a diagram for explaining the configuration of the semiconductor device 100B as explained in FIG. The circuit includes a current-voltage converter 101, a current switch 102, and a voltage-current converter 103.

[0059] The transistor 111A and the transistor 111B of the current switch unit 102 shown in FIG. 11B has a back gate electrode. The back gate electrode is connected to a back gate voltage V BG The OS transistor 111A and the transistor 111B is the back gate voltage V BG By controlling the electrical characteristics such as the threshold voltage Therefore, the electrical characteristics of the transistor, such as normally off and normally on, can be The back gate electrode of the OS transistor is , may be connected to the gate electrode. By using this configuration, The amount of current can be increased.

[0060] FIG. 4B shows a specific configuration of another modified example of the semiconductor device 100 described above in FIG. 2A. 4B is a diagram for explaining an example of the semiconductor device 100C shown in FIG. As shown in FIG. 1, the circuit includes a current-voltage converter 101, a current switch 102, and a voltage-current converter 103. The mixer circuit shown in FIG. 4B is the same as the single-balanced mixer circuit described in FIG. 2A. corresponds to a different, double-balanced mixer circuit.

[0061] The current-voltage conversion unit 101 includes a resistance element 131A and a resistance element 131B. The pressure converter 101 converts the signal V IF + and V IF - Outputs the signal V IF - is the signal V I F + The signal V is the inverted signal of IF + is the signal V IFCurrent switch section 102 is the signal LO + Transistor 111A and transistor 111D are provided, Signal LO - The transistors 111B and 111C are provided with The transistors 111A to 111D are OS transistors. , signal V RF + a transistor 121A to which a signal V RF - is given The transistors 121A and 121B are GaN transistors. Signal V RF - is the signal V RF + The signal V is the inverted signal of RF + is the signal V RF This is sometimes the case.

[0062] The semiconductor device 100C receives the signal V RF , signal LO, and signal V according to the frequency of IF Exit Signal V IF The frequency of the signal V RF The frequency of the signal LO is f1, and the frequency of the signal LO is f2. Then, the signal V with frequency (f1-f2) or (f1+f2) IF + and V IF - of It can be generated.

[0063] FIG. 5A shows a specific configuration of another modified example of the semiconductor device 100 described above in FIG. 2A. 5A is a diagram for explaining an example of a semiconductor device 100D, which is the same as that described in FIG. , a current-voltage conversion unit 101, a current switch unit 102, a voltage-current conversion unit 103, and a bias It has a voltage holding unit 105.

[0064] The bias voltage holding unit 105 holds a bias voltage for operating the voltage-current conversion unit 103. The bias voltage holding unit 105 holds the bias voltage. The voltage-current converter 103 converts the input signal V RF Current I according to RF It is easier to flush The bias voltage holding unit 105 may be a bias voltage holding circuit or simply a circuit. It may also be called a holding circuit.

[0065] The bias voltage holding unit 105 includes a capacitance element 151, an inductor 152, and a transistor 15 3 and a capacitance element 154. The transistor 153 is connected to the control signal S W By controlling , and a node N g To Bahia voltage V bias The transistor 153 is an OS transistor, so that the off-state current Therefore, the bias voltage holding unit 105 can minimize the current flowing through the transistor 153. By turning it off, node N g The bias voltage V applied to bias to continue to hold can be done.

[0066] 5B is a timing chart for explaining the operation of the bias voltage holding unit 105 in FIG. 5A. As shown in FIG. 5B, the control signal S W is set to H level and The transistor 153, which functions as a node N g is the bias voltage V b ias By turning off the transistor 153, the bias voltage Vbi as is node N g A signal V RF is given and signal V RF Following the change of g The bias voltage V bias This fluctuates. The change in potential causes a current I to flow through transistor 121A. RF can be increased do.

[0067] The inductor 152 shown in FIG. 5A is formed by processing a conductor into a predetermined shape on a substrate. 6A and 6B show a semiconductor device according to one embodiment of the present invention. In the semiconductor device 100, a layer including a transistor and a layer including an inductor are stacked on a substrate. FIG. 2 is a diagram for schematically illustrating a layer containing the insulating film;

[0068] In the schematic diagram of the semiconductor device 100E shown in FIG. 6A, the substrate 140 shown in FIG. 3B, the layer Layer 141, layer 142, layer 143, and layer 144 including inductor 152 are shown. 44 is provided on top of layer 142. That is, layer 144 including inductor 152 is It can be placed on top of a layer containing a transistor, or it can be placed on a semiconductor layer as shown in FIG. As in device 100F, layer 144 may be disposed between layers containing transistors. The inductor may be formed with a conductor having a thickness of, for example, about 2 μm. By configuring the bias voltage holding unit 105 as 0E and 100F, a configuration including the bias voltage holding unit 105 can be formed on the substrate. It can be achieved.

[0069] FIG. 7A shows a specific configuration of another modified example of the semiconductor device 100 described above in FIG. 2A. 7A is a diagram for explaining an example in which a current switch unit The transistor sizes of the transistors 111A and 111B of the transistor 102 are 10C, which is a schematic representation of the transistor 121A being larger than the transistor 121A of the voltage-current converter 103.

[0070] The transistors 111A and 111B of the current switch unit 102 The transistor size is set to the transistor size of the transistor 121A of the voltage-current conversion unit 103. By making it larger than 100, the amount of current determined by the transistor of the voltage-current conversion unit 103 can be controlled. The OS transistor can be operated as a switch without any restrictions. The current flow rate is smaller than that of a standard-sized GaN transistor. The channel length is preferably shorter than that of the GaN transistor. The channel width of the transistor is preferably larger than the channel width of the GaN transistor. With this configuration, the amount of current flowing through the current switch unit 102 is controlled by the voltage-current converter 10 It can approach 3.

[0071] The transistor 111A of the current switch unit 102 and the transistor 111B of the current switch unit 102 are OS transistors. When the transistor size of transistor 111B is increased, the OS transistor can be placed For example, the schematic diagram of the semiconductor device 100H shown in FIG. As shown in the figure, a layer 142 having an OS transistor is divided into a plurality of layers 142A, 142B By stacking the OS transistors, the circuit area where the OS transistors can be placed can be increased. can be done.

[0072] 8A to 8C show the stacked structure of the semiconductor device 100A described above with reference to FIG. 3B and the like. 8A to 8C are diagrams for explaining specific configuration examples. In the figure, each structure (layer 141, layer 142, layer 143) on the substrate 140 described in FIG. 3B etc. The figure shows a schematic representation of the arrangement of the elements.

[0073] In FIG. 8A, a layer 141, a layer 142, and a layer 143 are provided on a substrate 140, and a GaN layer is also provided. The transistor 131 is a transistor and is disposed between the layer 141 and the substrate 140. The buffer layer 145 is shown. The buffer layer 145 is used to separate different types of semiconductors from the substrate 140. The structure shown in FIG. 8A is provided for forming a nitride semiconductor such as GaN, which is a conductive layer. By this, a layer 141 having the transistor 121 and the transistor 13 are formed on the substrate 140. A layer 143 having a transistor 111 is provided, and a layer 142 having a transistor 111 is laminated thereon in this order. It can be configured as follows.

[0074] In FIG. 8B, a substrate 140 having a layer 141 disposed on a buffer layer 145 and a transistor A layer 143 having the transistor 131 and a layer 142 having the transistor 111 are stacked. The semiconductor device is formed by bonding the substrate 146 and the transistors to each other. The substrate 146 is a structure in which the transistor 121 of the layer 141 is S. Since it is an i-transistor, a silicon substrate such as a SIMOX substrate or an SOI substrate is used. As a technique for bonding substrates, plasma activation Bonding technology, Cu-Cu bonding, and other techniques for bonding substrates can be used. do.

[0075] In FIG. 8C, a substrate 140 is provided with a layer 141 on a layer 143 and a buffer layer 145. and a substrate 147 on which a layer 142 having a transistor 111 is stacked. 1 illustrates an example of a configuration in which the transistors are electrically connected to form a semiconductor device by connecting the transistors. The substrate 147 is a semiconductor substrate because the transistor 121 in the layer 142 is an OS transistor. In addition to silicon substrates, glass substrates and the like can also be used.

[0076] One aspect of the present invention is a power supply circuit including a current-voltage converter, a current switch, and a voltage-current converter. In a semiconductor device that functions as an active mixer, the transistor of the current switch is The transistors in the voltage-current converter are GaN transistors. This reduces the change in off-current caused by fluctuations in transistor characteristics, leading to lower power consumption. It is possible to provide an excellent semiconductor device. Even when fluctuations in the characteristics of semiconductor devices are likely to occur, we provide semiconductor devices with excellent operational reliability. The layer having the OS transistor can be formed by a GaN transistor and a Si A transistor having a different type of semiconductor layer, such as a semiconductor layer, is stacked. Therefore, it is possible to provide a miniaturized semiconductor device.

[0077] (Embodiment 2) In this embodiment, an integrated circuit including the semiconductor device 100 shown in the above embodiment is An example of the configuration of a wireless communication device will be described with reference to Figs. 9 and 10. In this embodiment, a smartphone will be described as an example of a wireless communication device. , tablet PCs (Personal Computers), notebook PCs, and other The wireless communication device according to the present embodiment may be a wireless communication terminal. It is possible to apply this to a device that can perform this.

[0078] In the block diagram of the wireless communication device 10 shown in FIG. 9, an antenna ANT, an application A power processor 11, a baseband processor 12, an integrated circuit 13 (IC: Integra ted Circuit), memory 14, battery 15, power management IC (PM IC:Power Management Integrated Circuit)1 6, display unit 17, camera unit 18, operation input unit 19, audio IC 20, microphone 21, and and a speaker 22. The integrated circuit 13 is an RF (Radio Frequency y) Also called IC or wireless chip.

[0079] In order to support 5G communication standards, multiple antennas are installed according to multiple frequency bands. can be done.

[0080] The application processor 11 reads out a program stored in the memory 14. The wireless communication device 10 has a function of performing processing to realize various functions of the wireless communication device 10. For example, The application processor 11 reads the OS (Operating System) from the memory 14. m) Execute the program and run the application that uses this OS program as the operating base. It has the function of executing application programs.

[0081] The baseband processor 12 encodes data transmitted and received by the wireless communication device 10. The function of performing baseband processing, including (e.g., error correction coding) processing or decoding processing, etc. Specifically, the baseband processor 12 processes the transmission data into the application program. The data is received from the processor 11, and the received data is encoded and stored in the integrated circuit. The baseband processor 12 also has a function of transmitting the signal from the integrated circuit 13 to the It receives the received data from the application, decrypts the received data, and sends it to the application. The processor 11 has a function of transmitting the received data to the processor 11.

[0082] The integrated circuit 13 performs modulation or demodulation processing on data transmitted and received by the wireless communication device 10. Specifically, the integrated circuit 13 receives from the baseband processor 12 The received transmission data is modulated by a carrier wave to generate a transmission signal, which is then transmitted via the antenna ANT. The integrated circuit 13 also has a function of outputting a transmission signal via the antenna ANT. A reception signal is received, and the reception signal is demodulated using a carrier wave to generate reception data. It has the function of transmitting data to the baseband processor 12.

[0083] The memory 14 stores programs and data used by the application processor 11. The memory 14 has the function of storing the stored data even if the power is cut off. The non-volatile memory stores the data, and the stored data is cleared when the power is interrupted. and a volatile memory.

[0084] The battery 15 is used when the wireless communication device 10 operates without relying on an external power supply. Note that the wireless communication device 10 does not use the battery 15 even when an external power source is connected. The battery 15 can be a dual-mode battery that can be charged and discharged. It is preferable to use a secondary battery.

[0085] The power management IC 16 generates an internal power supply voltage from a battery 15 or an external power supply. This internal power supply voltage is supplied to each block of the wireless communication device 10. At this time, the power management IC 16 performs internal The power management IC 16 has the function of controlling the power supply voltage. The internal power supply voltage is controlled based on instructions from the processor 11. The component IC 16 can also control the supply and cut-off of the internal power supply voltage for each block. In addition, the power management IC 16 supplies power to the battery 15 when an external power supply is available. It also has the function of controlling charging.

[0086] The display unit 17 is a liquid crystal display device or a light-emitting display device, and is The display unit 17 has a function of displaying various images according to the processing in the display unit 11. The displayed image includes a user interface in which the user gives operational instructions to the wireless communication device 10. This includes images from cameras, videos, etc.

[0087] The camera unit 18 acquires an image in accordance with an instruction from the application processor 11. The operation input unit 19 is operated by the user to give operation instructions to the wireless communication device 10. The audio IC 20 functions as a user interface for The audio data transmitted from the application processor 11 is decoded and output to the speaker 22. In addition, the audio IC 20 has the function of encoding the audio information obtained from the microphone 21. The audio data is then sent to the application processor 11. It has the function of outputting.

[0088] 10 is a block diagram for explaining an example of the configuration of the integrated circuit 13. The integrated circuit 13 includes a low-noise amplifier 201, a mixer 202, a low-pass filter 203, a variable a gain amplifier 204, an analog-to-digital conversion circuit 205, an interface unit 206, and a digital a digital-to-analog converter circuit 207, a variable gain amplifier 208, a low-pass filter 209, 10, the amplifier 210, the power amplifier 211, and the oscillator circuit 212. The antenna ANT, duplexer DUP, and baseband processor 12 are also shown. The low noise amplifier 201, the mixer 202, the low pass filter 203, the variable gain amplifier 204, and the The amplifier 204 and the analog-to-digital converter circuit 205 are the receiving circuit block, the digital-to-analog converter block, and the analog-to-digital converter block. Log conversion circuit 207, variable gain amplifier 208, low-pass filter 209, mixer 210 , and power amplifier 211 may be referred to as a transmission circuit block.

[0089] The baseband processor 12 and the integrated circuit 13 are each implemented on an individual semiconductor chip. The duplexer DUP includes an antenna switch and the like.

[0090] The low noise amplifier 201 amplifies the signal received by the antenna ANT with low noise. The semiconductor device 202 corresponds to the configuration including the semiconductor device 100 described in the first embodiment. The oscillator 202 demodulates and down-converts (frequency-converts) the signal from the oscillator circuit 212. The low-pass filter 203 removes unwanted high-frequency components from the signal from the mixer 202. The variable gain amplifier 204 converts the output signal of the low-pass filter 203 into an analog signal. The signal is amplified with a gain that takes into account the input range of the analog-to-digital conversion circuit 205. The conversion circuit 205 converts the analog signal from the variable gain amplifier 204 into a digital signal. The digital signal is input to the baseband processor 12 via the interface unit 206. is output.

[0091] The digital-to-analog conversion circuit 207 converts the digital signal received by the interface unit 206 into The variable gain amplifier 208 converts the digital-to-analog conversion circuit 2 The low-pass filter 209 amplifies the output signal from the variable gain amplifier 208. The mixer 210 removes unnecessary high frequency components from the signal. The mixer 210 converts the signal from the oscillation circuit 212 into a signal from the semiconductor device 100. The power amplifier 211 performs modulation and up-conversion (frequency conversion). The output signal of the amplifier 210 is amplified by a predetermined gain and output.

[0092] The configurations, structures, methods, and the like shown in this embodiment may be the same as those shown in other embodiments. It can be used in combination with other methods as appropriate.

[0093] (Embodiment 3) In this embodiment, a transistor applicable to the semiconductor device described in the above embodiment will be described. As an example, a structure in which transistors having different electrical characteristics are stacked is 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.

[0094] A part of the cross-sectional structure of the semiconductor device is shown in FIG. The capacitor 550, the transistor 500, the transistor 650, and the capacitor 600 are included. FIG. 12A is a cross-sectional view of the transistor 500 in the channel length direction, and FIG. 12C is a cross-sectional view of transistor 500 in the channel width direction, and FIG. 12D is a cross-sectional view of transistor 550 in the channel width direction. For example, the transistor 500 is the same as the transistor shown in the above embodiment. Transistor 550 corresponds to transistor 131, and transistor The transistor 650 corresponds to the transistor 121. The capacitor 600 corresponds to the capacitor 151. is equivalent to

[0095] Transistor 500 is an OS transistor. In FIG. The capacitor element 600 is provided above the transistor 550 and the transistor 650. The transistor 550, the transistor 650, and the transistor 500 are provided above the do.

[0096] The transistor 550 is provided on a substrate 311, and includes a conductor 316, an insulator 315, and a substrate A semiconductor region 313 consisting of a part of 311 functions as a source region or a drain region. It has a low resistance region 314a and a low resistance region 314b.

[0097] As shown in FIG. 12C, transistor 550 is formed by connecting the top surface and channel of semiconductor region 313. The side surfaces in the width direction of the transistor are covered with a conductor 316 via an insulator 315. By making the transistor 550 a fin type, the effective channel width increases, This can improve the on-state characteristics of the transistor 550. Since the supply of the current can be increased, the off characteristics of the transistor 550 can be improved. do.

[0098] The transistor 550 may be a p-channel transistor or an n-channel transistor. Either a transistor or a resistor may be used.

[0099] The region where the channel of the semiconductor region 313 is formed, the region in the vicinity thereof, the source region, or In the low resistance region 314a which becomes the drain region and the low resistance region 314b, silicon It preferably contains a semiconductor such as a silicon-based semiconductor, and it preferably contains single crystal silicon. Or Ge (germanium), SiGe (silicon germanium), GaAs (gallium It may be made of materials containing gallium aluminum arsenide (GaAlAs) or GaAlAs (Gallium Aluminum Arsenide). Silicon with effective mass controlled by applying stress to the crystal lattice and changing the lattice spacing. Alternatively, GaAs and GaAlAs may be used to form a transistor. The Star 550 is a HEMT (High Electron Mobility Transistor) stor) can also be used.

[0100] The low resistance region 314a and the low resistance region 314b are formed by the semiconductor layer applied to the semiconductor region 313. In addition to the conductive material, elements that impart n-type conductivity, such as arsenic and phosphorus, or p-type conductivity, such as boron, are added. It contains elements that impart electrical conductivity to the material.

[0101] The conductor 316, which functions as a gate electrode, is made of arsenic, phosphorus, or the like, which provides n-type conductivity. Semiconductor materials such as silicon that contain elements or elements that give them p-type conductivity, such as boron Conductive materials such as aluminum, metal, alloy, or metal oxide materials can be used. .

[0102] Since the work function is determined by the material of the conductor, it is necessary to select the material of the conductor. Specifically, the conductor is made of nitride silicon, and the threshold voltage of the transistor can be adjusted. It is preferable to use materials such as tantalum or tantalum nitride. To achieve this, metal materials such as tungsten and aluminum are used as layers for the conductor. It is preferable to use tungsten, in particular, in terms of heat resistance.

[0103] The transistor 550 is formed on a silicon on insulator (SOI) substrate. It may be formed using, for example.

[0104] In addition, for the SOI substrate, oxygen ions are implanted into a mirror-polished wafer, and then the wafer is heated to a high temperature. This allows an oxide layer to form at a certain depth from the surface, and also removes defects that have occurred in the surface layer. SIMOX (Separation by Implanted Oxygen) substrate and growth of microvoids formed by hydrogen ion implantation by heat treatment Smart Cut method, ELTRAN method (registered trademark: Epi SOI substrates formed by using techniques such as tactile layer transfer (TTL) are used. A transistor formed using a single crystal substrate may have a single crystal in the channel formation region. It has a semiconductor.

[0105] Here, the transistor 650 will be described. The transistor 650 is a transistor The transistor 650 is formed on the same substrate as the transistor 550. The transistor is formed using a semiconductor layer formed on a silicon-on-insulator (SOI) substrate. 650 is a nitride semiconductor having gallium in the channel forming region. As an example of a semiconductor layer containing gallium, gallium nitride is preferably used. Examples include GaN (hereinafter referred to as GaN).

[0106] A semiconductor device using GaN for the semiconductor layer 654 will be described with reference to FIG. GaN is formed by providing a buffer layer 652 on the substrate 311 and growing single crystal Ga It can be formed by epitaxial growth of N. The single crystal GaN corresponds to the semiconductor layer 654. In FIG. An example using a silicon substrate is shown.

[0107] When forming the transistor 650, a semiconductor layer 656 is epitaxially grown on the semiconductor layer 654. It is preferable to use a semiconductor layer grown by thermal growth. When the semiconductor layer 654 is GaN, The semiconductor layer 656 is preferably AlGaN. For example, aluminum nitride (AlN) is The band gap is approximately twice that of N (6.2 eV), and the electrostatic breakdown field is approximately four times that of GaN (12 MV / cmK) and thermal conductivity approximately 1.5 times that of GaN (2.9W / cmK), making it a highly superior material. Therefore, AlN and AlN-GaN mixed crystals, AlGaN is a preferred material for high-power, high-frequency devices. High Electron Mobility Transistor (HEMT) or) can operate at higher voltages than HEMTs that use GaN as the channel region. At the interface between GaN and AlGaN, a polarization effect occurs between GaN and AlGaN. In other words, in a transistor with a HEMT structure, The 2DEG is the channel forming region.

[0108] The conductor 330 is provided on the semiconductor layer 656. The conductor 330 is Equivalent to 50 source or drain.

[0109] The insulator 324 is sandwiched between the conductor 658 and the semiconductor layer 656. The conductor 658 is the gate electrode, and the insulator 324 is the gate insulator of the transistor 650. The insulator 324 may be silicon oxide, aluminum oxide, or hafnium oxide. For example, the insulator 324 may be made of silicon oxide, aluminum oxide, or the like. or hafnium oxide, etc., the off-state current of the transistor 650 Further, to explain the gate insulator in detail, the gate insulator is made of SiO2 It is preferable that the film is an Al2O3 film or an HfO2 film.

[0110] Also, the transistor 650 preferably has a recessed gate structure. Transistor 650 shows an example having a recessed gate structure. Since the transistor 650 has a recessed gate structure, the off-state current of the transistor 650 is reduced. The recessed gate structure is a gate electrode that forms a channel region. The semiconductor layer 656 is etched to thin the semiconductor layer 656. The area of ​​the semiconductor layer 656 that is thinned by etching is called a recessed area. The depletion enhancement of the EG allows for a high threshold voltage. The increased concentration of G allows a large current to flow.

[0111] Over the transistor 550, the insulator 320, the insulator 322, the insulator 324, and the insulator The edge members 326 are stacked in order.

[0112] The insulators 320, 322, 324, and 326 may be, for example, an acid. silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, Aluminum oxynitride, aluminum nitride oxide, aluminum nitride, or the like may be used.

[0113] In this specification, silicon oxynitride refers to a material having a higher content of oxygen than nitrogen in 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 high content. Aluminum oxide nitride is a material that has a higher oxygen content than nitrogen. It refers to a material that contains more nitrogen than oxygen as a constituent.

[0114] The insulator 322 serves to eliminate a step caused by the transistor 550 and the like provided below. For example, the top surface of the insulator 322 may have a function as a planarizing film. To improve flatness, the surface is flattened by a planarization process using chemical mechanical polishing (CMP) or other methods. It may be possible.

[0115] The insulator 324 is also provided with a substrate 311 or a transistor 550 or the like. A film having a barrier property to prevent diffusion of hydrogen and impurities is formed in the area where the star 500 is provided. It is preferable to use

[0116] An example of a film having a barrier property against hydrogen is silicon nitride formed by CVD. Here, the transistor 500 or the like having an oxide semiconductor can be preferably used. When hydrogen diffuses into a semiconductor element, the characteristics of the semiconductor element may be deteriorated. Therefore, a structure for suppressing hydrogen diffusion between the transistor 500 and the transistor 550 is provided. Specifically, a film that suppresses the diffusion of hydrogen is preferably used. The film should have a low

[0117] The amount of hydrogen desorption can be analyzed using, for example, thermal desorption spectroscopy (TDS). For example, the amount of hydrogen desorbed from the insulator 324 can be determined by TDS analysis as follows: In the range of 50°C to 500°C, the amount of desorption converted to hydrogen atoms is Converted to a hit, it's 10 x 10 15 atoms / cm 2 Less than or equal to 5 x 10 15 a toms / cm 2 The following is fine.

[0118] It is preferable that the insulator 326 has a lower dielectric constant than the insulator 324. For example, The dielectric constant of the insulator 326 is preferably less than 4, more preferably less than 3. The relative dielectric constant of the insulator 326 is preferably 0.7 times or less than the relative dielectric constant of the insulator 324, and more preferably 0.6 times or less. By using a material with a low dielectric constant as the interlayer film, the parasitic capacitance generated between wirings can be reduced. can be reduced.

[0119] In addition, the insulators 320, 322, 324, and 326 are provided with capacitive elements. 600, or the conductor 328 and the conductor 330 connected to the transistor 500 are buried. The conductor 330 is also connected to the source or drain of the transistor 650. The conductor 328 and the conductor 330 function as a plug or a wiring. The conductor having the function of a plug or wiring is In this specification and the like, the same reference numerals may be used to denote the wiring and the The wiring and the plug to be connected may be an integral part. In some cases, the conductor functions as a plug, and in other cases, a part of the conductor functions as a plug.

[0120] The materials for each plug and wiring (conductor 328, conductor 330, etc.) include metal materials, Conductive materials such as alloy materials, metal nitride materials, or metal oxide materials can be used in single or multilayer configurations. High-temperature materials such as tungsten and molybdenum, which have both heat resistance and electrical conductivity, can be used. It is preferable to use a material with a melting point, and it is preferable to use tungsten. It is preferable to form the wiring board from a low-resistance conductive material such as aluminum or copper. This can reduce the wiring resistance.

[0121] A wiring layer may be provided on the insulator 326 and the conductor 330. For example, in FIG. An insulator 350, an insulator 352, and an insulator 354 are stacked in this order. In addition, a conductor 356 is formed on the insulators 350, 352, and 354. The conductor 356 is connected to a plug that connects to the transistor 550 and a plug that connects to the transistor 650. The conductor 356 functions as a plug or wiring for connecting the conductor 328, The conductive material 330 can be used to form the conductive material 330 .

[0122] For example, the insulator 350 has a barrier property against hydrogen, similar to the insulator 324. It is preferable to use an insulator having a barrier property against hydrogen. It is preferable that the insulating material 350 has a barrier property against hydrogen. A conductor having a barrier property against hydrogen is formed in the opening. The transistor 550 or the transistor 650 is a transistor 500 and a transistor 650 formed by a barrier layer. It can be separated from transistor 550 or transistor 650. This can suppress the diffusion of hydrogen into 00.

[0123] 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 transistor 550 can be suppressed while maintaining the overall conductivity. In this case, the tantalum nitride layer having a barrier property against hydrogen is It is preferable that the insulating material 350 has a structure in which the insulating material 350 is in contact with the insulating material 350.

[0124] A wiring layer may be provided on the insulator 354 and the conductor 356. For example, in FIG. An insulator 360, an insulator 362, and an insulator 364 are stacked in this order. In addition, a conductor 366 is formed on the insulators 360, 362, and 364. The conductor 366 functions as a plug or wiring. The conductors 328 and 330 can be formed using the same materials.

[0125] For example, the insulator 360 has a barrier property against hydrogen, similar to the insulator 324. It is preferable to use an insulator having a barrier property against hydrogen. It is preferable that the insulating material 360 has a barrier property against hydrogen. A conductor having a barrier property against hydrogen is formed in the opening. The transistor 550 or the transistor 650 is a transistor 500 and a transistor 650 formed by a barrier layer. It can be separated from transistor 550 or transistor 650. This can suppress the diffusion of hydrogen into 00.

[0126] A wiring layer may be provided on the insulator 364 and the conductor 366. For example, in FIG. An insulator 370, an insulator 372, and an insulator 374 are stacked in this order. In addition, a conductor 376 is formed on the insulators 370, 372, and 374. The conductor 376 functions as a plug or wiring. The conductors 328 and 330 can be formed using the same materials.

[0127] For example, the insulator 370 has a barrier property against hydrogen, similar to the insulator 324. It is preferable to use an insulator having a barrier property against hydrogen. In particular, an insulator 370 having a barrier property against hydrogen is useful. A conductor having a barrier property against hydrogen is formed in the opening. The transistor 550 or the transistor 650 is a transistor 500 and a transistor 650 formed by a barrier layer. It can be separated from transistor 550 or transistor 650. This can suppress the diffusion of hydrogen into 00.

[0128] A wiring layer may be provided on the insulator 374 and the conductor 376. For example, in FIG. An insulator 380, an insulator 382, ​​and an insulator 384 are stacked in this order. In addition, a conductor 386 is formed on the insulators 380, 382, ​​and 384. The conductor 386 functions as a plug or wiring. The conductors 328 and 330 can be formed using the same materials.

[0129] For example, the insulator 380 has a barrier property against hydrogen, similar to the insulator 324. It is preferable to use an insulator having a barrier property against hydrogen. It is preferable that the insulator 380 has a barrier property against hydrogen. A conductor having a barrier property against hydrogen is formed in the opening. The transistor 550 or the transistor 650 is a transistor 500 and a transistor 650 formed by a barrier layer. It can be separated from transistor 550 or transistor 650. This can suppress the diffusion of hydrogen into 00.

[0130] In the above, the wiring layer including the conductor 356, the wiring layer including the conductor 366, the conductor 376 The wiring layer including the conductor 386 has been described. The semiconductor device is not limited to this. The number of layers may be three or less, or five or more wiring layers similar to the wiring layer including the conductor 356. That's fine.

[0131] On the insulator 384 are an insulator 510, an insulator 512, an insulator 514, and an insulator 516. are stacked in this order. It is preferable that the insulator 516 is made of a material that has a barrier property against oxygen and hydrogen. It's nice.

[0132] For example, the insulator 510 and the insulator 514 may include, for example, the substrate 311, the transistor The area where the transistor 550 is provided or the area where the transistor 650 is provided is A film with barrier properties that prevents hydrogen and impurities from diffusing is used in the region where 00 is provided. Therefore, the insulator 510 and the insulator 514 are preferably the same as the insulator 324. Materials can be used.

[0133] 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, However, the diffusion of hydrogen may deteriorate the characteristics of the semiconductor element. The hydrogen diffusion occurs between the transistor 500 and the transistor 550 or the transistor 650. It is preferable to use a film that suppresses hydrogen diffusion. The film has a small amount of elemental detachment.

[0134] In addition, as a film having a barrier property against hydrogen, for example, an insulator 510 and an insulator 514 uses metal oxides such as aluminum oxide, hafnium oxide, and tantalum oxide. It is preferable that

[0135] In particular, aluminum oxide is highly resistant to oxygen and water, which can cause fluctuations in the electrical characteristics of transistors. It has a high blocking effect that prevents impurities such as oxygen and moisture from penetrating the membrane. Aluminum oxide is a material that can withstand hydrogen, moisture, and other chemicals during and after the transistor manufacturing process. This can prevent impurities from entering the transistor 500. This can suppress the release of oxygen from the oxide that makes up the transistor. It is suitable for use as a protective film for the substrate 500.

[0136] For example, the insulators 512 and 516 may be made of the same material as the insulator 320. In addition, materials with relatively low dielectric constants can be used as insulators. For example, the insulator 512 and the insulator 513 can reduce the parasitic capacitance between the wirings. The edge 516 may be a silicon oxide film, a silicon oxynitride film, or the like.

[0137] In addition, the insulators 510, 512, 514, and 516 are made of conductive materials. 518, and the conductors (for example, conductor 503) that constitute the transistor 500 are filled in. The conductor 518 is embedded in the capacitor 600, the transistor 550, or the transistor 560. The conductor 518 functions as a plug or wiring that connects to the transistor 650. , conductor 328, and conductor 330 can be formed using the same materials.

[0138] In particular, the insulator 510 and the conductor 518 in the region in contact with the insulator 514 are oxidized to oxygen, hydrogen, and It is preferable that the conductive material has a barrier property against water. The transistor 550 or the transistor 650 is a transistor 500 and a compound semiconductor material containing oxygen, hydrogen, and and a layer having a barrier property against water, and the transistor 550 or The diffusion of hydrogen from the transistor 650 to the transistor 500 can be suppressed.

[0139] Above the insulator 516 is the transistor 500 .

[0140] As shown in FIGS. 12A and 12B, transistor 500 includes an insulator 514 and an insulator 516. A conductor 503 disposed so as to be embedded in an insulator 516, an insulator 516 and a conductor An insulator 520 disposed on the insulator 503, and an insulator 522 disposed on the insulator 520. , an insulator 524 disposed on the insulator 522, and an oxide layer disposed on the insulator 524. 530a, an oxide 530b disposed on the oxide 530a, and an oxide 530b disposed on the oxide 530b. Conductor 542a and conductor 542b are spaced apart from each other, and conductor 542a and conductor The conductive material 542a is disposed on the conductive material 542b, and an opening is formed between the conductive material 542a and the conductive material 542b so as to overlap the conductive material 542a. the insulator 580 disposed on the bottom and side of the opening, the insulator 545 disposed on the bottom and side of the opening, and the insulator 54 and a conductor 560 disposed on the forming surface of the 5.

[0141] 12A and 12B, the oxide 530a, the oxide 530b, the conductive The insulator 544 is disposed between the conductor 542a and the conductor 542b and the insulator 580. As shown in FIGS. 12A and 12B, the conductor 560 is preferably made of an insulator 560. 45, and a conductor 560a provided inside the conductor 560a. 12A and 12B. As shown in FIG. 1, an insulator 574 is disposed on top of an insulator 580, a conductor 560, and an insulator 545. It is preferable to place

[0142] In this specification and the like, the oxide 530a and the oxide 530b are collectively referred to as oxides. The conductor 542a and the conductor 542b are collectively referred to as the conductor 530. Sometimes it's 42.

[0143] In the transistor 500, an oxide is formed in the region where the channel is formed and in the vicinity thereof. 5 shows a structure in which two layers of a carbide 530a and an oxide 530b are stacked. One embodiment of the present invention is not limited to this. For example, a single layer or three layers of oxide 530b may be used. The above-mentioned laminated structure may be provided.

[0144] Although the transistor 500 shows the conductor 560 as having a two-layer structure, One embodiment of the present invention is not limited to this. For example, the conductor 560 may have a single layer structure. 11 and 12A, or may be a laminated structure of three or more layers. The transistor 500 is an example, and the configuration is not limited to this, and may vary depending on the circuit configuration, driving method, etc. An appropriate transistor can be used accordingly.

[0145] Here, the conductor 560 functions as the gate electrode of the transistor, and the conductors 542a and and the conductor 542b function as a source electrode and a drain electrode, respectively. Thus, conductor 560 is inserted through the opening in insulator 580 and through conductors 542a and 542b. The conductor 560, the conductor 542a, and the conductor 542b are formed so as to be embedded in the region sandwiched between them. The placement of the conductor 542b is selected to be self-aligned with the opening of the insulator 580. In the transistor 500, the gate electrode is disposed between the source electrode and the drain electrode. Therefore, the conductor 560 can be arranged in a self-aligned manner without providing a margin for alignment. Since the transistor 500 can be formed without any problem, the area occupied by the transistor 500 can be reduced. This allows for miniaturization and high integration of semiconductor devices.

[0146] Furthermore, the conductor 560 is self-aligned in the region between the conductors 542a and 542b. Since the conductor 560 is formed, the area where the conductor 560 overlaps with the conductor 542a or the conductor 542b is As a result, the conductor 560 does not have a gap between the conductor 542a and the conductor 542b. The parasitic capacitance formed can be reduced. This improves the scanning speed and provides high frequency characteristics.

[0147] Conductor 560 may function as a first gate (also called a top gate) electrode. The conductor 503 also functions as a second gate (also called a bottom gate) electrode. In this case, the voltage applied to the conductor 503 may be different from the voltage applied to the conductor 560. The threshold voltage of the transistor 500 is controlled by changing them independently without linking them together. In particular, applying a negative voltage to the conductor 503 turns on the transistor 5 It is possible to increase the threshold voltage of 00 and reduce the off-current. When a negative voltage is applied to the conductor 503, the voltage applied to the conductor 560 is larger than when no voltage is applied. The drain current can be reduced when the applied voltage is 0V.

[0148] The conductor 503 is arranged to overlap the oxide 530 and the conductor 560. When a voltage is applied to the conductor 560 and the conductor 503, a current is generated from the conductor 560. The electric field generated by the conductor 503 is connected to the electric field generated by the conductor 503, and the choke formed in the oxide 530 is generated. The channel forming area can be covered.

[0149] 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 rounded channel (S-channel) configuration. In this case, the S-channel configuration is achieved by using a conductive layer that functions as the source and drain electrodes. The side and periphery of the oxide 530 in contact with the conductive body 542a and the conductive body 542b form a channel. The conductive material 542a and the conductive material 542b are I-shaped like the conductive material 542a. The side and periphery of the oxide 530 in contact with 542b are in contact with the insulator 544, so In this specification and the like, the I-type can be the type described later. In addition, the S-chan disclosed in the present specification and the like can be treated as the same as high-purity genuine products. The nel configuration is different from the fin and planar configurations. By adopting this, the resistance to the short channel effect is improved. This makes it possible to provide a transistor in which this phenomenon is unlikely to occur.

[0150] The conductor 503 has the same structure as the conductor 518, and the insulator 514 and the insulator Conductor 503a is formed in contact with the inner wall of the opening of 516, and conductor 503b is formed further inside. In the transistor 500, the conductor 503a and the conductor 503b However, one embodiment of the present invention is not limited to this. For example, the conductor 503 may be a single layer or a laminated structure of three or more layers. stomach.

[0151] Here, the conductor 503a is a diffusion layer for 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.) can be suppressed. It is preferable to use a conductive material that has the function of preventing oxygen from permeating through the conductive material. 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. has the function of suppressing the diffusion of any one or all of the above oxygen.

[0152] For example, the conductor 503a has a function of suppressing the diffusion of oxygen, so that the conductor 503 This can prevent b from being oxidized and the electrical conductivity from decreasing.

[0153] When the conductor 503 also functions as a wiring, the conductor 503b is made of tungsten, copper, or the like. It is preferable to use a conductive material having high conductivity, such as aluminum or aluminum-based. 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.

[0154] The insulators 520, 522, and 524 function as a second gate insulating film. Possess the ability.

[0155] 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 a large amount of oxygen. The oxygen is released from the film by heating. In this specification and elsewhere, the oxygen released by heating is sometimes referred to as "excess oxygen." That is, the insulator 524 has a region containing excess oxygen (also called an "excess oxygen region"). It is preferable that the insulator containing such excess oxygen is formed in contact with the oxide 530. By providing the oxide 530, oxygen vacancies (V O :oxygen vacancy This can reduce the oxide film thickness (also referred to as oxide film thickness) and improve the reliability of the transistor 500. When hydrogen enters the oxygen vacancy in the oxide 530, the defect (hereinafter referred to as V O It may be called H ) can act as a donor, generating electrons as carriers. Some of them may combine with oxygen, which bonds with metal atoms, to generate electrons, which act as carriers. Therefore, a transistor using an oxide semiconductor containing a large amount of hydrogen is a normally-on transistor. 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 It is preferable to make it highly pure or substantially highly pure. O H is ten To obtain an oxide semiconductor with reduced impurities, it is necessary to remove impurities such as moisture and hydrogen from the oxide semiconductor. (also called "dehydration" or "dehydrogenation treatment") and supplying oxygen to the oxide semiconductor. It is important to compensate for the oxygen deficiency by adding oxygen to the surface (also called "oxygenation treatment"). O H etc. By using an oxide semiconductor in which the amount of impurities is sufficiently reduced for a channel formation region of a transistor, This makes it possible to impart stable electrical properties.

[0156] As an insulator having an excess oxygen region, specifically, an oxide in which a part of oxygen is released by heating is used. It is preferable to use oxide materials. Oxides that release oxygen when heated are called TDS (Th Thermal Desorption Spectroscopy (DSS) analysis revealed that the oxygen atoms The converted amount of oxygen desorption is 1.0 x 10 18 atoms / cm 3 or more, preferably 1.0 x10 19 atoms / cm 3 More preferably, 2.0 × 10 19 atoms / c m 3 or more, or 3.0 x 10 20 atoms / cm 3 The oxide film is as described above. The surface temperature of the film during the TDS analysis is 100°C or higher and 700°C or lower, or The temperature is preferably in the range of 00°C or higher and 400°C or lower.

[0157] In addition, the insulator having the excess oxygen region and the oxide 530 are brought into contact with each other and subjected to heat treatment. One or more of microwave treatment and RF treatment may be performed. By performing this, water or hydrogen in the oxide 530 can be removed. At 530, a reaction occurs in which the VoH bond is broken, in other words, "V O H→Vo+ The reaction "H" occurs, and some of the hydrogen generated at this time is It combines with oxygen to form H2O, which is then removed from the oxide 530 or the insulators adjacent to the oxide 530. In addition, some of the hydrogen may be gettered to the conductor 542. .

[0158] The microwave treatment may be carried out using, for example, an apparatus having a power source that generates high-density plasma. Alternatively, it is preferable to use a device having a power source that applies 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 high density plasma generated Oxygen radicals are efficiently introduced into the oxide 530 or into the insulator near the oxide 530. The microwave treatment can be carried out at a pressure of 133 Pa or more, preferably 200 The microwave treatment may be performed at a pressure of 400 Pa or more, more preferably 400 Pa or more. The gases introduced into the device are, for example, oxygen and argon, with an oxygen flow rate ratio (O / (O2+Ar)) is set to 50% or less, preferably 10% or more and 30% or less.

[0159] In addition, during the manufacturing process of the transistor 500, the surface of the oxide 530 is exposed. The heat treatment is preferably carried out at a temperature of, for example, 100° C. or higher and 450° C. or lower. The heat treatment is preferably performed at a temperature of 350° C. or higher and 400° C. or lower. Or in an inert gas atmosphere, or oxidizing gas is 10 ppm or more, 1% or more, or For example, it is preferable to carry out the heat treatment in an oxygen atmosphere. This supplies oxygen to the oxide 530, and oxygen vacancies (V O ) can be reduced. The heat treatment may be carried out under reduced pressure. Alternatively, the heat treatment may be carried out under nitrogen gas or nitrogen gas. After heat treatment in an active gas atmosphere, oxidizing gas was added at 10p to compensate for the oxygen that was released. The treatment may be carried out in an atmosphere containing at least pm, at least 1%, or at least 10% of an oxidizing gas. After heat treatment in an atmosphere containing 10 ppm or more, 1% or more, or 10% or more, Alternatively, the heat treatment may be performed in a nitrogen gas or inert gas atmosphere.

[0160] 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 the substance 530 recombines with the oxygen vacancy to form V. O inhibits the formation of H It is possible.

[0161] Also, if the insulator 524 has an excess oxygen region, the insulator 522 may be oxygen-rich (e.g., It has the function of suppressing the diffusion of oxygen atoms, oxygen molecules, etc. (the oxygen is less likely to permeate). It is preferable that:

[0162] The insulator 522 has a function of suppressing the diffusion of oxygen and impurities, and the oxide 530 The oxygen contained in the conductor 503 is preferably not diffused to the insulator 520 side. This can prevent the insulator 524 and the oxide 530 from reacting with oxygen.

[0163] The insulator 522 may be, for example, aluminum oxide, hafnium oxide, aluminum and hafnium oxide. Oxides containing hafnium (hafnium aluminate), tantalum oxide, zirconium oxide, Lead zirconate titanate (PZT), strontium titanate (SrTiO3), or ( Insulators containing so-called high-k materials such as Ba,Sr)TiO3 (BST) are deposited in a single layer or As transistors become smaller and more highly integrated, Thinning the gate insulating film can cause problems such as leakage current. By using a high-k material as an insulator that functions as a transistor, the physical thickness can be maintained. This makes it possible to reduce the gate voltage during transistor operation.

[0164] In particular, it has the function of suppressing the diffusion of impurities and oxygen (the oxygen is less likely to permeate). a) 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 ( It is preferable to use materials such as hafnium aluminate. When the insulator 522 is formed, the insulator 522 prevents oxygen from being released from the oxide 530 and prevents the transistor from being damaged. This layer functions as a layer that suppresses the intrusion of impurities such as hydrogen from the periphery of the capacitor 500 into the oxide 530. do.

[0165] Alternatively, for example, aluminum oxide, bismuth oxide, germanium oxide, or the like may be added to these insulators. um, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, Zirconium oxide may be added, or these insulators may be nitrided. Silicon oxide, silicon oxynitride or silicon nitride may be laminated on the insulator. .

[0166] The insulator 520 is preferably thermally stable. For example, silicon oxide and Silicon oxide nitride and silicon oxynitride are suitable because they are thermally stable. By combining this insulator with silicon oxide or silicon oxynitride, Furthermore, it is possible to obtain an insulator 520 having a laminated structure with a high relative dielectric constant.

[0167] 12A and 12B, the transistor 500 has a three-layer stacked structure. As the second gate insulating film, an insulator 520, an insulator 522, and an insulator 524 are illustrated. However, the second gate insulating film may have a single layer, two layers, or a laminated structure of four or more layers. In this case, the laminated structure is not limited to the same material, but may be a laminated structure made of different materials. It can also be composed of

[0168] The transistor 500 includes an oxide 530 including a channel formation region, and an oxide semiconductor The oxide semiconductor is made of at least one of In and Zn. For example, the oxide 530 may contain 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.

[0169] The metal oxide that functions as an oxide semiconductor may be formed by a sputtering method. Alternatively, the deposition may be performed by ALD (Atomic Layer Deposition). Note that a metal oxide functioning as an oxide semiconductor will be described in detail in other embodiments. do.

[0170] In addition, the metal oxide that functions as a channel forming region in the oxide 530 has a band It is preferable to use a material with a gap of 2 eV or more, preferably 2.5 eV or more. As shown in Fig. 1, by using a metal oxide with a wide band gap, the off-state current of a transistor can be reduced. can be reduced.

[0171] The oxide 530 has an oxide 530a under the oxide 530b, so that the oxide 530a The diffusion of impurities from the structure formed below the oxide 530b can be suppressed. can.

[0172] The oxide 530 has a structure of a plurality of oxide layers with different atomic ratios of each metal atom. Specifically, it is preferable that the metal oxide used for the oxide 530a has a content of 0.01% or less among the constituent elements. The atomic ratio of element M is the atomic ratio of element M in the constituent elements of the metal oxide used for oxide 530b. It is preferable that the atomic ratio of M is larger than that of M. In addition, the metal oxide used for the oxide 530a is In the metal oxide used for 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 in the oxide 530a, the atomic ratio of In to element M is It is preferable that the atomic ratio of In to M in the metal oxide is larger than that of In.

[0173] In addition, the energy of the conduction band minimum of the oxide 530a is greater than the energy of the conduction band minimum of the oxide 530b. In other words, the electron affinity of the oxide 530a is preferably higher than the electron affinity of the oxide 530a. is preferably smaller than the electron affinity of oxide 530b.

[0174] Here, at the junction between the oxide 530a and the oxide 530b, the energy of the bottom of the conduction band is In other words, the junction of oxide 530a and oxide 530b The energy level of the conduction band minimum at the junction changes continuously or is called a continuous junction. To achieve this, the oxide 530a and the oxide 530b are This is advantageous in that the defect level density of the mixed layer formed by this method is reduced.

[0175] Specifically, the oxide 530a and the oxide 530b have a common element other than oxygen (mainly By using the oxide as a component, it is possible to form a mixed layer with a low defect level density. When the material 530b is an In-Ga-Zn oxide, the oxide 530a is an In-Ga-Zn It is preferable to use oxide, Ga-Zn oxide, gallium oxide, etc.

[0176] At this time, the main path of the carriers is the oxide 530b. By forming the oxide 530a and the oxide 530b in this manner, the defect state density at the interface between the oxide 530a and the oxide 530b is reduced. Therefore, the influence of interface scattering on carrier conduction is reduced, and The transistor 500 can obtain a high on-state current.

[0177] On the oxide 530b, a conductor 542 is formed, which functions as a source electrode and a drain electrode. The conductors 542a and 542b are provided as follows: are aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum Niobium, tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium Strontium, Beryllium, Indium, Ruthenium, Iridium, Strontium, Lanthanum or an alloy containing the above metal element as a component, or the above metal element It is preferable to use an alloy in which the above-mentioned materials are combined. For example, tantalum nitride, titanium nitride, tantalum tungsten, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum , ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum It is preferable to use oxides containing tantalum and nickel. titanium and aluminum nitrides, tantalum and aluminum nitrides, and titanium oxides Ruthenium, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel Oxides containing chlorine are conductive materials that are resistant to oxidation, or that maintain conductivity even when they absorb oxygen. Furthermore, metal nitride films such as tantalum nitride are preferred because they are materials that can withstand hydrogen or It is preferable because it has a barrier property against oxygen.

[0178] In addition, in FIG. 12A, the conductor 542a and the conductor 542b are shown as having a single layer configuration. However, 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 top, and copper on a copper-magnesium-aluminum alloy film Two-layer structure with a copper film laminated on a titanium film, two-layer structure with a copper film laminated on a tungsten film It may also be a two-layer structure in which these are laminated.

[0179] Also, a titanium film or titanium nitride film and an aluminum film overlaid on the titanium film or titanium nitride film are used. An aluminum film or a copper film is laminated, and a titanium film or a titanium nitride film is further formed thereon. A three-layer structure consisting of a molybdenum film or molybdenum nitride film and a molybdenum film or molybdenum nitride film. An aluminum or copper film is layered on top of the molybdenum film, and then a molybdenum or In addition, there are three-layer structures in which indium oxide, tin oxide or molybdenum nitride is formed. Alternatively, a transparent conductive material containing zinc oxide may be used.

[0180] As shown in FIG. 12A, the conductor 542a (conductor 542b) of the oxide 530 At the interface and in the vicinity thereof, a region 543a and a region 543b are formed as low resistance regions. In this case, the region 543a may be used 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 the region 543a and the region 543b.

[0181] 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 In such a case, a metal compound layer containing the component 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. become.

[0182] The insulator 544 is provided to cover the conductor 542a and the conductor 542b. The insulator 544 prevents oxidation of the conductive material 542a and the conductive material 542b. It may be provided to cover the side of object 530 and to be in contact with insulator 524.

[0183] Insulator 544 includes hafnium, aluminum, gallium, yttrium, and zirconium. Smoke, tungsten, titanium, tantalum, nickel, germanium, neodymium, lanthanum Alternatively, a metal oxide containing one or more selected from magnesium, etc. may be used. The insulator 544 may be made of silicon oxynitride or silicon nitride. It can also be used.

[0184] 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 film. This is preferable because it is difficult to crystallize during heat treatment at room temperature. The body 542b is made of a material that is resistant to oxidation or that does not significantly decrease in conductivity even when it absorbs oxygen. In this case, the insulator 544 is not an essential component. Just calculate it.

[0185] By including the insulator 544, impurities such as water and hydrogen contained in the insulator 580 can be removed. Diffusion into the oxide 530b can be suppressed via the insulator 545. The excess oxygen contained in the insulator 580 can prevent the conductor 560 from being oxidized. do.

[0186] The insulator 545 functions as a first gate insulating film. Similar to the body 524, an insulator containing excess oxygen and releasing oxygen when heated is used. It is preferable to form

[0187] Specifically, silicon oxide having excess oxygen, silicon oxynitride, silicon nitride oxide, Silicon nitride, fluorine-doped silicon oxide, carbon-doped silicon oxide, carbon, and Silicon oxide doped with nitrogen and silicon oxide having vacancies can be used. In particular, silicon oxide and silicon oxynitride are preferred because they are stable to heat.

[0188] By providing an insulator containing excess oxygen as the insulator 545, oxygen can be removed from the insulator 545. Oxygen can be effectively supplied to the channel forming region of the oxide 530b. As with 524, the concentration of impurities such as water or hydrogen in the insulator 545 is reduced. The thickness of the insulator 545 is preferably 1 nm or more and 20 nm or less.

[0189] 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 insulating layer 545 and the conductor 560. It is preferable to suppress the diffusion of oxygen from the body 545 to the conductor 560. By providing a metal oxide, the diffusion of excess oxygen from the insulator 545 to the conductor 560 is suppressed. In other words, it is possible to suppress the decrease in the amount of excess oxygen supplied to the oxide 530. In addition, oxidation of the conductor 560 due to excess oxygen can be suppressed. Any material that can be used for the insulator 544 may be used.

[0190] Note that the insulator 545 may have a stacked structure similar to the second gate insulating film. As transistors become smaller and more highly integrated, the gate insulating film becomes thinner, which reduces leakage current and other problems. Therefore, the insulator that functions as the gate insulating film should be high-k By using a laminated structure of a material that is thermally stable, the thickness of the material can be maintained while maintaining the thickness of the material. This allows for a reduction in the gate voltage during transistor operation. A simple laminated structure can be achieved.

[0191] The conductor 560 that functions as the first gate electrode has a two-layer structure in FIGS. 12A and 12B. However, it may have a single layer structure or a laminated structure of three or more layers.

[0192] The conductor 560a is a hydrogen atom, a hydrogen molecule, a water molecule, a nitrogen atom, a nitrogen molecule, or a nitrogen oxide molecule. (N2O, NO, NO2, etc.), conductive material with the function of suppressing the diffusion of impurities such as copper atoms It is preferable to use a material containing a small amount of 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 at least one of the conductors. Since 60a has the function of suppressing the diffusion of oxygen, 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 scattering include tantalum, tantalum nitride, and tantalum fluoride. It is preferable to use ruthenium oxide or ruthenium oxide as the conductor 560a. Therefore, an oxide semiconductor that can be used for the oxide 530 can be used. By forming the conductive material 60b by sputtering, the electrical resistance value of the conductive material 560a is reduced. It can be made into a conductor. This is called an OC (Oxide Conductor) electrode. It is possible.

[0193] 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 conductor with high conductivity, such as tungsten, copper, or aluminum. The conductor 560b can be made of a conductive material containing aluminum as a main component. For example, a laminated structure of titanium or titanium nitride and the above conductive material may be used. good.

[0194] The insulator 580 is disposed on the conductor 542a and the conductor 542b via the insulator 544. The insulator 580 preferably has an excess oxygen region. 80 includes silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and fluorine. Nitrogen-doped silicon oxide, carbon-doped silicon oxide, carbon- and nitrogen-doped silicon oxide It is preferable that the material be silicon oxide, silicon oxide having pores, or resin. Silicon oxide and silicon oxynitride are particularly 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 can

[0195] The insulator 580 preferably has an excess oxygen region. Oxygen is released upon heating. By providing the insulator 580, oxygen in the insulator 580 can be 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 that

[0196] 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 connected to the opening of the insulator 580 and the conductor 542a. It is formed so as to be embedded in the region sandwiched between the bodies 542b.

[0197] In miniaturizing semiconductor devices, it is required to shorten the gate length. It is necessary to prevent the conductivity of the conductor 60 from decreasing. In this embodiment, the conductor 560 may have a shape with a high aspect ratio. The conductor 560 is provided so as to be embedded in the opening of the insulator 580. Even a shape with a high ratio can be formed without causing the conductor 560 to collapse during the process. Cut.

[0198] The insulator 574 is disposed on 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 surface. Thus, an excess oxygen region can be provided in the insulator 545 and the insulator 580. This allows oxygen to be supplied into the oxide 530 from the excess oxygen region.

[0199] For example, the insulator 574 may be hafnium, aluminum, gallium, yttrium, Zirconium, tungsten, titanium, tantalum, nickel, germanium, or magnesium It is possible to use a metal oxide containing one or more metals selected from the group consisting of cadmium, cadmium, and sulphur. Cut.

[0200] 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 sputtering is performed. The aluminum oxide film formed by this method is a source of oxygen and also a barrier for impurities such as hydrogen. It can also function as a film.

[0201] 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 in the film. is preferably reduced.

[0202] Also, the insulating material 581, the insulating material 574, the insulating material 580, and the insulating material 544 are formed. The conductor 540a and the conductor 540b are disposed in the opening. The conductor 540a and the conductor 540b are provided opposite each other with the conductor 560 in between. 0b has the same configuration as conductor 546 and conductor 548, which will be described later.

[0203] 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. The insulator 582 may be made of the same material as the insulator 514. For example, aluminum oxide may be used. It is preferable to use metal oxides such as tungsten oxide, hafnium oxide, and tantalum oxide.

[0204] In particular, aluminum oxide is highly resistant to oxygen and water, which can cause fluctuations in the electrical characteristics of transistors. It has a high blocking effect that prevents impurities such as oxygen and moisture from penetrating the membrane. Aluminum oxide is a material that can withstand hydrogen, moisture, and other chemicals during and after the transistor manufacturing process. This can prevent impurities from entering the transistor 500. This can suppress the release of oxygen from the oxide that makes up the transistor. It is suitable for use as a protective film for the substrate 500.

[0205] An insulator 586 is provided on the insulator 582. The insulator 586 is The same materials as those of 320 can be used. In addition, these insulators have a relatively low dielectric constant. By using a material with high insulating properties, the parasitic capacitance between wiring can be reduced. The edge 586 can be a silicon oxide film, a silicon oxynitride film, or the like.

[0206] Also, the insulator 520, the insulator 522, the insulator 524, the insulator 544, the insulator 580, the insulator The insulator 574, the insulator 581, the insulator 582, and the insulator 586 are provided with the conductor 546 and and a conductor 548 and the like are embedded therein.

[0207] The conductor 546 and the conductor 548 are connected to the capacitor 600, the transistor 500, or The conductor 546 functions as a plug or wiring connected to the transistor 550. The conductor 548 is made of the same material as the conductor 328 and the conductor 330. It is possible.

[0208] 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, In addition, it is possible to prevent hydrogen from penetrating the transistors 500. The whole may be wrapped in an insulator that has high barrier properties against hydrogen or water. When forming an opening to surround the transistor 500, for example, the insulator 522 or the insulator An opening is formed that reaches the insulator 514, and the above-mentioned barrier is placed in contact with the insulator 522 or the insulator 514. If a highly flexible insulator is formed, the manufacturing process of the transistor 500 can be performed simultaneously. 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.

[0209] Next, a capacitor 600 is provided above the transistor 650. 600 includes a conductor 610, a conductor 620, and an insulator 630.

[0210] Furthermore, a conductor 612 may be provided over the conductor 546 and the conductor 548. 612 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 conductive material 610 can be formed in the same process.

[0211] Conductor 612 and conductor 610 may be made of molybdenum, titanium, tantalum, tungsten, or the like. Metal film containing elements selected from the group consisting of silicon, aluminum, copper, chromium, neodymium, and scandium or a metal nitride film containing the above-mentioned elements (tantalum nitride film, titanium nitride film, nitride Molybdenum film, tungsten nitride film, etc. can be used. oxides containing tungsten oxide, indium zinc oxides containing tungsten oxide Lead oxide, indium oxide with titanium oxide, indium tin oxide with titanium oxide, Conductive materials such as indium zinc oxide and indium tin oxide doped with silicon oxide It can also be applied.

[0212] 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 used. Conductors with barrier properties and highly conductive conductors A highly adhesive conductor may be formed.

[0213] 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 are both heat-resistant and conductive, are used. It is preferable to use tungsten, and it is particularly preferable to use tungsten. When forming the same structure as other components, low-resistance metal materials such as Cu (copper) and Al (aluminum) are used. Minium) or the like can be used.

[0214] An insulator 640 is provided on the conductor 620 and the insulator 630. The insulator 40 can be made of the same material as the insulator 320. , and may function as a planarizing film that covers the underlying unevenness.

[0215] By using this structure, a semiconductor device including a transistor having an oxide semiconductor This allows for miniaturization or high integration.

[0216] Examples of a substrate that can be used for a semiconductor device according to one embodiment of the present invention include a glass substrate, a quartz substrate, and the like. Plate, sapphire substrate, ceramic substrate, metal substrate (e.g., stainless steel substrate, Substrate with stainless steel foil, tungsten substrate, tungsten foil semiconductor substrates (e.g., single crystal semiconductor substrates, polycrystalline semiconductor substrates, or SOI (Silicon on Insulator) substrate In addition, a plate having heat resistance capable of withstanding the processing temperature of this embodiment can be used. A plastic substrate may be used. An example of a glass substrate is barium borosilicate glass. Glass, aluminosilicate glass, or aluminoborosilicate glass, or soda glass Other examples include glass-ceramics.

[0217] Alternatively, the substrate may be a flexible substrate, a laminated film, a paper containing a fibrous material, or A flexible substrate, a laminated film, a base film, etc. can be used. Examples of films include polyethylene terephthalate. Polyethylene naphthalate (PET), Polyethersulfone (PES) ), and polytetrafluoroethylene (PTFE) are typical plastics. For example, synthetic resin such as acrylic resin is used. Examples include polyethylene, polyester, polyvinyl fluoride, and polyvinyl chloride. Examples include polyamide, polyimide, aramid resin, epoxy resin, and inorganic vapor deposition film. In particular, semiconductor substrates, single crystal substrates, SOI substrates, etc. By manufacturing transistors using this method, variations in characteristics, size, and shape are reduced. This allows the manufacture of small-sized transistors with high current capacity. By constructing a circuit using such transistors, it is possible to reduce the power consumption of the circuit or to increase the integration density of the circuit. This can be achieved.

[0218] In addition, a flexible substrate is used as the substrate, and transistors, resistors, and Alternatively, a substrate and a transistor, a resistor, and a capacitor may be formed. A release layer may be provided between the capacitor and the like. Or, after the whole process is completed, it can be separated from the substrate and used for transferring to another substrate. In this case, transistors, resistors, and / or capacitors are mounted on substrates with poor heat resistance or flexible materials. The above-mentioned peeling layer may be formed of, for example, a tungsten film and a silicon oxide film. The structure is a laminated structure of an inorganic film with an inorganic film, or a structure in which an organic resin film such as polyimide is formed on a substrate. A silicon film containing hydrogen or the like can be used.

[0219] That is, a semiconductor device is formed on a substrate, and then the semiconductor device is transferred to another substrate. An example of the substrate onto which the semiconductor device is transferred is a substrate on which the above-described transistor is formed. In addition to the substrates that can be used, paper substrates, cellophane substrates, aramid film substrates, polyimide Film substrate, stone substrate, wood substrate, fabric substrate (natural fibers (silk, cotton, linen), synthetic fibers (nylon) lon, polyurethane, polyester) or regenerated fiber (acetate, cupra, rayon These include recycled polyester, leather substrates, and rubber substrates. By using the substrate, it is possible to manufacture flexible semiconductor devices and unbreakable semiconductor devices. It is possible to improve the structure, provide heat resistance, and reduce the weight or thickness.

[0220] By providing a semiconductor device on a flexible substrate, an increase in weight can be suppressed and the semiconductor device is less likely to be damaged. Therefore, a semiconductor device can be provided.

[0221] <Transistor variation 1> The transistor 500A shown in FIGS. 13A to 13C has the same structure as that shown in FIGS. 12A and 12B. 13A is a top view of transistor 500A. 13B is a cross-sectional view of the transistor 500A in the channel length direction, and FIG. 13C is a cross-sectional view of the transistor 500A in the channel length direction. 13A is a cross-sectional view of the transistor 500A in the channel width direction. For clarity, some elements are omitted. The same can be said for other transistors included in the semiconductor device of one embodiment of the present invention, such as the transistor 550. can be applied.

[0222] The transistor 500A shown in FIGS. 13A to 13C includes an insulator 552, an insulator 513, 12A and 12B in that the transistor 500 has the insulator 404. The transistor 500A is different from the transistor 500A in that the insulator 552 is in contact with the side surface of the conductor 540a. and an insulator 552 is provided in contact with the side surface of the conductor 540b. Furthermore, transistor 500A differs from transistor 500 in that it does not have an insulator 520. It is different from the Transistor 500.

[0223] The transistor 500A having the configuration shown in FIGS. 13A to 13C includes an insulator 512 and an insulator 513. 513 is provided. In addition, the insulator 404 is provided on the insulator 574 and the insulator 513. It can be done.

[0224] In the transistor 500A having the configuration shown in FIGS. 13A to 13C, the insulator 514, the insulator 516, insulator 522, insulator 524, insulator 544, insulator 580, and insulator 57 4 is patterned, and the insulating material 404 covers them. The insulator 404 is formed on the top surface of the insulator 574, the side surface of the insulator 574, the side surface of the insulator 580, and the insulator The side of the body 544, the side of the insulator 524, the side of the insulator 522, the side of the insulator 516, the insulator The oxide 530 and the like are in contact with the side surface of the insulating body 514 and the top surface of the insulating body 513, respectively. , and is isolated from the outside by insulators 404 and 513.

[0225] The insulator 513 and the insulator 404 are made of at least hydrogen (e.g., hydrogen atoms, hydrogen molecules, etc.). It is preferable that the insulator 51 has a high function of suppressing the diffusion of water molecules. 3 and the insulator 404 are made of a material with high hydrogen barrier properties, such as silicon nitride or nitride. It is preferable to use silicon oxide, which prevents hydrogen and the like from diffusing into the oxide 530. This can suppress the deterioration of the characteristics of the transistor 500A. This can improve the reliability of the semiconductor device of one embodiment of the present invention.

[0226] Insulator 552 includes insulator 581, insulator 404, insulator 574, insulator 580, and The insulator 552 is provided in contact with the insulator 544. The insulator 552 suppresses the diffusion of hydrogen or water molecules. For example, the insulator 552 is preferably a material having a high hydrogen barrier property. An insulator such as silicon nitride, aluminum oxide, or silicon nitride oxide is used. In particular, silicon nitride is a material with high hydrogen barrier properties, so that the insulator 55 It is preferable to use a material with high hydrogen barrier properties as the insulator 552. As a result, impurities such as water or hydrogen are transported from the insulator 580 to the conductor 540a and the conductor 540b. Diffusion into the oxide 530 through the insulator 58 can be suppressed. The oxygen contained in the conductive material 540a is prevented from being absorbed by the conductive material 540b. As described above, the reliability of the semiconductor device of one embodiment of the present invention can be improved.

[0227] <Transistor variation 2> An example of the configuration of the transistor 500B will be described with reference to FIGS. 14A, 14B, and 14C. FIG. 14A is a top view of transistor 500B. FIG. 14B shows the transistor 500B shown in FIG. 14A with a dashed line. 14A. FIG. 14C is a cross-sectional view of the L1-L2 region indicated by the dashed line W1-W in FIG. 14A is a cross-sectional view of two parts. Note that in the top view of FIG. 14A, some elements are shown in a simplified form for clarity. The description is omitted.

[0228] Transistor 500B is a modification of transistor 500. Therefore, to avoid repetition, we will mainly focus on transistors. The differences from the controller 500 will be explained below.

[0229] The conductor 560 functioning as the first gate electrode is made up of the conductor 560a and the conductor 56 Conductor 560a has a conductor 560b on it. Conductor 560a is composed of hydrogen atoms, hydrogen molecules, water molecules, copper It is preferable to use a conductive material that has the function of suppressing the diffusion of impurities such as atoms. or a function of suppressing the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.). It is preferable to use a conductive material having such a property.

[0230] The conductor 560a has a function of suppressing the diffusion of oxygen, and therefore the material of the conductor 560b In other words, by having the conductor 560a, the conductor 560 The oxidation of b is suppressed, and the decrease in electrical conductivity can be prevented.

[0231] In addition, the insulator 545 is formed so as to cover the upper and side surfaces of the conductor 560 and the side surface of the insulator 545. It is preferable to provide the insulator 544. The insulator 544 is a material that can absorb impurities such as water or hydrogen, and It is advisable to use an insulating material that has the function of suppressing the diffusion of oxygen. For example, aluminum oxide It is preferable to use magnesium oxide or hafnium oxide. Nesium, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, acid metal oxides such as lanthanum oxide, neodymium oxide or tantalum oxide, silicon oxide nitride or Silicon nitride or the like can be used.

[0232] By providing the insulator 544, oxidation of the conductor 560 can be suppressed. By providing the insulator 544, impurities such as water and hydrogen contained in the insulator 580 are absorbed into the transistor. This can prevent the diffusion of the electrons into the resistor 500B.

[0233] Transistor 500B has conductor 56 connected to a portion of conductor 542a and a portion of conductor 542b. Since the 0s overlap, the parasitic capacitance tends to be larger than that of the transistor 500. However, the operating frequency of the insulator 580 tends to be lower than that of the insulator 500. Since there is no need to provide an opening in the substrate 540 and fill in the conductor 560 or the insulator 545, High productivity compared to the transistor 500.

[0234] The configurations, structures, methods, and the like shown in this embodiment may be the same as those shown in other embodiments. It can be used in combination with other methods as appropriate.

[0235] (Fourth embodiment) In this embodiment, an oxide semiconductor, which is a type of metal oxide, will be described.

[0236] The metal oxide preferably contains at least indium or zinc. In addition to these, aluminum, gallium, It is preferable that the material contains yttrium, tin, etc. Also, boron, silicon, titanium, etc. Iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, Selected from among odymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc. One or more of these may be included.

[0237] <Classification of crystal structures> First, the classification of crystal structures in oxide semiconductors will be explained with reference to FIG. 15A. FIG. 15A shows an oxide semiconductor, typically IGZO (a metal oxide containing In, Ga, and Zn). FIG. 1 is a diagram illustrating the classification of crystal structures of metal oxides.

[0238] As shown in FIG. 15A, oxide semiconductors are broadly divided into "amorphous" and "non-amorphous" oxide semiconductors. ) and "Crystalline" and "Crystal" Also, among "Amorphous" there are those that are completely amorphous. Also, "Crystalline" contains CAAC (ca xis-aligned crystalline), nc(nanocrystall ine), and CAC (cloud-aligned composite). (excluding single crystal and poly crys tal). The classification of "Crystalline" includes single crystals. l, polycrystalline, and completely amorphous are excluded. Also, "Crystal" includes single crystal and p Contains poly crystal.

[0239] The structures within the bold frame in Figure 15A are "Amorphous" and "Cr It is an intermediate state between "crystal" and "new crystal" In other words, the structure is in the It is completely different from the unstable "Amorphous" and "Crystal" This can be rephrased as a structure in which:

[0240] The crystal structure of the film or substrate can be determined by X-ray diffraction (XRD). The crystallinity can be evaluated using the crystallinity spectrum. The GIXD (Grazing-Incidence) of CAAC-IGZO films The XRD spectrum obtained by the GIXD measurement is shown in Figure 15B. This is also called the membrane method or the Seemann-Bohlin method. The XRD spectrum obtained by the measurement is simply referred to as the XRD spectrum. The composition of the CAAC-IGZO film is approximately In:Ga:Zn=4:2:3 [atomic ratio]. The thickness of the CAAC-IGZO film shown in Figure 15B is 500 nm.

[0241] As shown in Figure 15B, the XRD spectrum of the CAAC-IGZO film shows clear crystalline Specifically, in the XRD spectrum of the CAAC-IGZO film, A peak indicating the c-axis orientation is detected near 2θ=31°. The peak intensity at 2θ=31° is detected at the angle It is asymmetrical about the axis.

[0242] The crystal structure of the film or substrate was also analyzed by nanobeam electron diffraction (NBED). Diffraction patterns (ultra-small) observed by electron diffraction It can be evaluated by the electron diffraction pattern. The folding pattern is shown in Figure 15C. Figure 15C shows the NB method in which the electron beam is incident parallel to the substrate. The diffraction pattern observed by ED is shown in Figure 15C. The composition of the film is approximately In:Ga:Zn=4:2:3 [atomic ratio]. In the diffraction method, electron diffraction is performed with a probe diameter of 1 nm.

[0243] As shown in Figure 15C, the diffraction pattern of the CAAC-IGZO film shows multiple patterns indicating c-axis orientation. Several spots are observed.

[0244] <<Structure of oxide semiconductor>> In addition, when focusing on the crystal structure, oxide semiconductors may be classified differently from those shown in FIG. 15A. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. As a non-single-crystal oxide semiconductor, for example, the above-mentioned CAAC-OS Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-crystalline oxide semiconductors, and nc-OS. Pseudo-amorphous oxide semiconductor (a-like OS) e semiconductor), amorphous oxide semiconductor, etc.

[0245] Here, we will explain the details of the above-mentioned CAAC-OS, nc-OS, and a-like OS. and provide an explanation.

[0246] [CAAC-OS] The CAAC-OS has multiple crystalline regions, each of which has a c-axis aligned in a specific direction. The specific direction is the thickness direction of the CAAC-OS film. , in the normal direction to the surface on which the CAAC-OS film is formed, or in the normal direction to the surface of the CAAC-OS film. The crystalline region is a region in which the atomic arrangement has periodicity. When viewed as a crystal arrangement, the crystalline region is also a region with a uniform lattice arrangement. The OS has a region where multiple crystalline regions are connected in the ab-plane direction, and this region has strain. The distortion may occur in a region where multiple crystal regions are connected. The area where the orientation of the lattice arrangement changes between a region with one lattice arrangement and a region with a different lattice arrangement. In other words, the CAAC-OS has a c-axis orientation and no clear orientation in the ab-plane direction. It is an oxide semiconductor that has not been

[0247] Each of the plurality of crystalline regions is made up of one or more minute crystals (maximum diameter 10 When a crystalline region is made up of a single microcrystal (crystals less than 1 nm in size), The maximum diameter of the crystalline region is less than 10 nm. When such crystal regions are formed, the size of the crystal regions may be on the order of several tens of nanometers.

[0248] In-M-Zn oxide (element M is aluminum, gallium, yttrium, sulphur, CAAC-OS is a material selected from the group consisting of aluminum, titanium, and other materials. The layer containing element M, zinc (Zn), and oxygen (hereinafter referred to as the In layer) is The layered crystal structure (layered structure) is composed of a layer containing oxygen (hereinafter referred to as the (M,Zn) layer). Indium and element M can be substituted for each other. Therefore, the (M, Zn) layer may contain indium. The In layer may contain Zn. For example, it is observed as a lattice image in a high-resolution TEM image.

[0249] For example, when the structure of the CAAC-OS film is analyzed using an XRD device, the θ / 2θ phase In the out-of-plane XRD measurement using a can, two peaks indicating the c-axis orientation were observed. The peak indicating the c-axis orientation is detected at or near θ=31°. ) may vary depending on the type and composition of the metal elements that make up the CAAC-OS.

[0250] For example, in the electron diffraction pattern of the CAAC-OS film, multiple bright spots (spots) Note that one spot and another spot are the incident electron beams that have passed through the sample. The spot (also called the direct spot) is the center of symmetry, and the points are observed at positions that are point-symmetric. can be.

[0251] When the crystalline region is observed from the specific direction, the lattice arrangement within the crystalline region is a hexagonal lattice. However, the unit cell is not necessarily a regular hexagon, and may be a non-regular hexagon. The above distortion may have a lattice arrangement such as a pentagon or heptagon. -In OS, clear grain boundaries were confirmed even near the strain. In other words, the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is because the arrangement of oxygen atoms in the CAAC-OS is close-packed in the ab-plane direction. The bond distance between atoms changes when metal atoms are substituted. , it is believed that this is because distortion can be tolerated.

[0252] The crystal structure in which clear grain boundaries are observed is called polycrystal. The grain boundaries act as recombination centers, trapping carriers and forming transistors. It is highly likely that this will cause a decrease in on-state current and a decrease in field effect mobility. CAAC-OS, which has no visible grain boundaries, has a crystalline structure suitable for the semiconductor layer of a transistor. It is one of the crystalline oxides containing Zn to form CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are This is preferable because it can suppress the generation of grain boundaries more effectively than oxides.

[0253] CAAC-OS is an oxide semiconductor with high crystallinity and no clear grain boundaries. Therefore, the CAAC-OS is less susceptible to the decrease in electron mobility caused by grain boundaries. In addition, the crystallinity of oxide semiconductors may be reduced by the incorporation of impurities or the generation of defects. Therefore, CAAC-OS is an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, the physical properties of an oxide semiconductor having a CAAC-OS are stable. Therefore, oxide semiconductors having CAAC-OS are heat-resistant and highly reliable. C-OS is stable even under high temperatures (so-called thermal budget) in the manufacturing process. Therefore, using CAAC-OS for OS transistors increases the flexibility of the manufacturing process. It becomes possible to

[0254] [nc-OS] nc-OS is a material that can be used in microscopic areas (e.g., areas between 1 nm and 10 nm, especially areas between 1 nm and 10 nm). In other words, nc-OS has a periodic atomic arrangement in the region of 3 nm or less. It has small crystals. The size of the minute crystals is, for example, 1 nm or more and 10 nm or less. Since the size of these tiny crystals is between 1 nm and 3 nm, they are also called nanocrystals. In nc-OS, there is no regularity in the crystal orientation between different nanocrystals. Therefore, depending on the analytical method, nc-OS may be considered as a-like In some cases, it is difficult to distinguish between an OS and an amorphous oxide semiconductor. For example, in the case of an nc-OS film, , Structural analysis was performed using an XRD instrument, and out-of-plane analysis using θ / 2θ scan was performed. In the XRD measurement, no peaks indicating crystallinity were detected. However, electron beam circuits using electron beams with probe diameters larger than nanocrystals (e.g., 50 nm or larger) are being used. When electron diffraction (also called selected area electron diffraction) is performed, a diffraction pattern resembling a halo pattern is observed. On the other hand, for the nc-OS film, the size of the nanocrystals is close to or smaller than that of the nanocrystals. Electron beam diffraction (nanobeam) using an electron beam with a probe diameter (for example, 1 nm to 30 nm) When electron diffraction is performed, a ring-shaped region is formed around the direct spot. An electron diffraction pattern may be obtained in which multiple spots are observed.

[0255] [a-like OS] The a-like OS is an oxide semiconductor with a structure between the nc-OS and amorphous oxide semiconductor. A-like OS has pores or low density regions. The OS has lower crystallinity than the nc-OS and CAAC-OS. e-OS has a higher hydrogen concentration in the film than nc-OS and CAAC-OS.

[0256] <<Oxide semiconductor structure>> Next, the details of the above-mentioned CAC-OS will be explained. Regarding the formation of

[0257] [CAC-OS] CAC-OS is a type of metal oxide in which the elements constituting the metal oxide are 0.5 nm to 10 nm in size. Preferably, the material is unevenly distributed in a size of 1 nm to 3 nm or in the vicinity thereof. In the following, it is assumed that one or more metal elements are unevenly distributed in a metal oxide. The region having the metal element has a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm. A mixed state of particles with sizes of less than 1 m or close to that size is called a mosaic or patch state. .

[0258] Furthermore, CAC-OS is a material that is separated into a first region and a second region. The first regions are in a shape similar to a cloud, and the first regions are distributed throughout the film (hereinafter also referred to as a cloud shape). ) In other words, the CAC-OS is a mixture of the first area and the second area. It is a composite metal oxide having a structure in which

[0259] Here, the I ratio of the metal elements constituting the CAC-OS in the In-Ga-Zn oxide is The atomic ratios of n, Ga, and Zn are defined as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS of In-Ga-Zn oxide, the first region is the region where [In] is larger than [In] in the composition of the CAC-OS film. The second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Or, for example, the first region has [In] higher than the [In] in the second region. In this region, [Ga] is larger than [Ga] in the first region. In addition, the second region has a larger [Ga] than the [Ga] in the first region and a smaller [I [n] is smaller than [In] in the first region.

[0260] Specifically, the first region is mainly composed of indium oxide, indium zinc oxide, etc. The second region is a region containing gallium oxide, gallium zinc oxide, etc. In other words, the first region is called a region in which In is the main component. The second region can be rephrased as a region containing Ga as the main component. It is possible.

[0261] Note that there are cases where a clear boundary between the first region and the second region cannot be observed. .

[0262] For example, in the case of CAC-OS in In-Ga-Zn oxide, energy dispersive X-ray diffraction (EDX) Optical method (EDX:Energy Dispersive X-ray spectrosc) The EDX mapping obtained using the opy revealed a region containing In as the main component (the first region). The structure has a structure in which a first region (a first region) and a region (a second region) mainly composed of Ga are unevenly distributed and mixed. It can be confirmed that this is the case.

[0263] When CAC-OS is used in a transistor, the conductivity due to the first region and the conductivity due to the second region are The insulating properties due to the region act complementary to each other to provide a switching function (On In other words, the CAC-OS and has a conductive function in a part of the material and an insulating function in a part of the material, and By separating the conductive function from the insulating function, Therefore, by using CAC-OS in transistors, This allows for a high on-state current (I on ), high field-effect mobility (μ), and good switching This allows for realizing a switching operation.

[0264] Oxide semiconductors have a variety of structures, each of which has different characteristics. The oxide semiconductors in Two or more of AC-OS, nc-OS, and CAAC-OS may be included.

[0265] <Transistors containing oxide semiconductors> Next, a case where the oxide semiconductor is used in a transistor will be described.

[0266] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility can be obtained. Furthermore, a highly reliable transistor can be realized.

[0267] For the transistor, an oxide semiconductor with a low carrier concentration is preferably used. , the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 Less than 1 × 10 15 c m -3 or less, more preferably 1 × 10 13 cm -3 Less than or equal to 1×10 11 cm -3 or less, more preferably 1 × 10 10 cm -3Less than 1 x 10 -9 cm - 3 In order to reduce the carrier concentration of the oxide semiconductor film, The impurity concentration in the semiconductor film may be reduced to reduce the defect state density. A low impurity concentration and a low defect level density are called high purity intrinsic or substantially high purity intrinsic. The oxide semiconductor having a low carrier concentration is preferably a high-purity intrinsic or substantially high-purity intrinsic oxide. These are sometimes called compound semiconductors.

[0268] Furthermore, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states. Therefore, the trap level density may also be low.

[0269] In addition, the time required for the charges trapped in the trap levels of the oxide semiconductor to disappear is Therefore, the trap level density is high. A transistor in which a channel formation region is formed in an oxide semiconductor has unstable electrical characteristics. This may be the case.

[0270] Therefore, in order to stabilize the electrical characteristics of a transistor, the impurity concentration in the oxide semiconductor In order to reduce the impurity concentration in the oxide semiconductor, it is effective to reduce It is preferable to reduce the impurity concentration in the adjacent film. These include alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0271] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0272] When oxide semiconductors contain silicon or carbon, which are elements of Group 14, they are oxidized. Defect levels are formed in semiconductors, which is why defects in silicon and carbon in oxide semiconductors The concentration of silicon and carbon near the interface with the oxide semiconductor (secondary ion mass spectrometry) (SIMS: Secondary Ion Mass Spectrometry) The concentration obtained is 2 x 10 18 atoms / cm 3 Less than or equal to 2 x 10 17 a toms / cm 3 The following applies.

[0273] In addition, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect levels are formed. Therefore, alkali metals or alkaline earth metals may be included. Transistors using oxide semiconductors, which are widely used in semiconductors, tend to be normally on. Therefore, the concentration of alkali metals or alkaline earth metals in oxide semiconductors obtained by SIMS Degrees, 1 x 10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 Do the following:

[0274] In addition, when nitrogen is contained in an oxide semiconductor, electrons that serve as carriers are generated, and As a result, the nitrogen-containing oxide semiconductor becomes a semiconductor. The transistors used for the oxide semiconductors tend to be normally on. Therefore, if nitrogen is contained, trap levels may be formed. Therefore, the electrical properties of the oxide semiconductor obtained by SIMS may become unstable. The nitrogen concentration in 19 atoms / cm 3 Less than 5 x 1018 ato ms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 The following are more preferred: Kuha 5 x 10 17 atoms / cm 3 Do the following:

[0275] In addition, hydrogen contained in oxide semiconductors reacts with oxygen that bonds with metal atoms to form water. When hydrogen enters the oxygen vacancy, the electron carrier In addition, some of the hydrogen atoms may bond with the oxygen atoms that bond with the metal atoms, forming chiral ions. Therefore, it is necessary to use an oxide semiconductor containing hydrogen. Therefore, the hydrogen in the oxide semiconductor tends to cause a transistor to be normally on. It is preferable that the amount of Si in the oxide semiconductor is as small as possible. The hydrogen concentration obtained by MS was 1×10 20 atoms / cm 3 Less than 1x, preferably 10 19 atoms / cm 3 less than 5 × 10 18 atoms / cm 3 less than , and more preferably 1 × 10 18 atoms / cm 3 Make it less than.

[0276] By using an oxide semiconductor with sufficiently reduced impurities for a channel formation region of a transistor, This makes it possible to impart stable electrical properties.

[0277] The configurations, structures, methods, and the like shown in this embodiment may be the same as those shown in other embodiments. It can be used in combination with other methods as appropriate.

[0278] (Embodiment 5) In this embodiment, an application example of the above-described semiconductor device will be described.

[0279] [Semiconductor wafers, chips] 16A shows a top view of the substrate 711 before the dicing process is performed. For example, a semiconductor substrate (also called a "semiconductor wafer") can be used as 711. A plurality of circuit regions 712 are provided on the substrate 711. In this case, a semiconductor device according to one embodiment of the present invention, other functional circuits, or the like can be provided.

[0280] Each of the multiple circuit regions 712 is surrounded by an isolation region 713. A separation line (also called a "dicing line") 714 is set at a position where the separation line overlaps with the separation line. By cutting the substrate 711 along 714, a chip 715 including a circuit region 712 is formed on the substrate. The chip 715 can be cut out from the chip 711. An enlarged view of the chip 715 is shown in FIG.

[0281] In addition, a conductor or a semiconductor layer may be provided in the separation region 713. By providing a semiconductor layer, ESD that may occur during the dicing process is mitigated, and the dicing process In general, the dicing process involves cooling the substrate, grinding it, and Pure water with reduced resistivity due to the dissolution of carbon dioxide gas, etc., for the purposes of removing debris and preventing static electricity. By providing a conductor or semiconductor layer in the separation region 713, The amount of pure water used can be reduced, thereby reducing the production cost of semiconductor devices. Furthermore, the productivity of the semiconductor device can be improved.

[0282] The semiconductor layer provided in the separation region 713 has a band gap of 2.5 eV or more and 4.2 e It is preferable to use a material with an energy of 2.7 eV or less, preferably 2.7 eV or more and 3.5 eV or less. Such materials allow the accumulated charge to be slowly discharged, thus reducing the risk of ESD damage. This suppresses the sudden movement of charges due to electrostatic discharge, making it less likely that electrostatic breakdown will occur.

[0283] [Electronic Components] An example of applying the chip 715 to an electronic component will be described with reference to FIG. The electronic components are also called semiconductor packages or IC packages. There are multiple standards and names depending on the direction of insertion and the shape of the terminal.

[0284] The electronic component is assembled with the semiconductor device shown in the above embodiment in the assembly process (post-process). The semiconductor device is completed by combining it with other components.

[0285] The post-process will be described using the flowchart shown in FIG. After the element substrate having the semiconductor device shown in the embodiment is completed, the back surface (semiconductor The back surface (the surface on which no conductor devices are formed) is ground (step S 721) By thinning the element substrate through grinding, warping of the element substrate is reduced, and the electronic components are This allows for the product to be made smaller.

[0286] Next, a "dicing process" is performed to separate the element substrate into a plurality of chips (chips 715). (Step S722). Then, the separated chips are individually picked up and attached to the lead frame. Then, a "die bonding process" is performed (step S723). During the process, the chip and lead frame are joined using resin or tape. The appropriate method is selected depending on the product. The chip may be bonded onto a poser substrate.

[0287] Next, the leads of the lead frame and the electrodes on the chip are electrically connected with thin metal wires. The "wire bonding process" is carried out to electrically connect the thin metal wires (step S724). Silver wire or gold wire can be used for wire bonding. Bonding or wedge bonding can be used.

[0288] The wire-bonded chip is sealed with epoxy resin in the "encapsulation process (molding)" The sealing process is then carried out (step S725). The chip is filled with resin, and the circuitry built into the chip and the wires connecting the chip and leads are machined. It can protect from external mechanical forces and also prevents deterioration of characteristics (reduced reliability) due to moisture and dust. can be reduced.

[0289] Next, a "lead plating process" is carried out to plate the leads of the lead frame (step (Step S726). The plating process prevents the leads from rusting and allows them to be mounted on a printed circuit board later. This allows for more reliable soldering during the process. The leads are then cut and shaped. Then, a "molding step" is carried out (step S727).

[0290] Next, a "marking process" is carried out to print (mark) the surface of the package. Then, an "inspection process" is carried out to check whether the external appearance is good or not, whether there is any malfunction, etc. (Step S728). After passing through the "process" (step S729), the electronic component is completed.

[0291] A perspective view of the completed electronic component is shown in FIG. 17B. As an example, a perspective schematic diagram of a QFP (Quad Flat Package) is shown. The electronic component 750 shown in FIG. 17B shows leads 755 and semiconductor device 753. The semiconductor device 753 can be any of the semiconductor devices described in the above embodiment modes. do.

[0292] The electronic component 750 shown in FIG. 17B is mounted on, for example, a printed circuit board 752. A plurality of electronic components 750 are combined and electrically connected on a printed circuit board 752. By connecting the components together, a substrate (mounted substrate 754) on which electronic components are mounted is completed. The substrate 754 is used in electronic devices and the like.

[0293] [Electronic equipment] Next, examples of electronic devices including the semiconductor device according to one embodiment of the present invention or the electronic component will be described. Explanations will be given.

[0294] Examples of electronic devices using the semiconductor device or electronic component according to one embodiment of the present invention include televisions, monitors, and the like. Display devices such as monitors, lighting devices, desktop or notebook personal computers , word processors, DVDs (Digital Versatile Discs), etc. Image playback devices that play still images or videos stored on recording media, portable CD players , radio, tape recorder, headphone stereo, stereo, table clock, wall clock, Wireless telephone handsets, transceivers, mobile phones, car phones, portable game consoles, tablets large game machines such as pachinko machines, calculators, portable information terminals ("mobile information terminals") ), electronic organizers, e-book terminals, electronic translators, voice input devices, video cameras, Digital still cameras, electric shavers, microwave ovens and other high-frequency heating devices, electric rice cookers, Washing machines, vacuum cleaners, water heaters, electric fans, hair dryers, air conditioners, humidifiers, dehumidifiers Air conditioning equipment such as humidifiers, dishwashers, dish dryers, clothes dryers, futon dryers, electric refrigerators, Electric freezers, electric refrigerator-freezers, freezers for DNA storage, flashlights, tools such as chainsaws , smoke detectors, medical equipment such as dialysis machines. conveyors, elevators, escalators, industrial robots, power storage systems, power balance Examples include industrial equipment such as energy storage devices for standardization and smart grids.

[0295] In addition, mobile objects propelled by electric motors using power from a power storage device are also included in the category of electronic devices. The above-mentioned mobile units include, for example, electric vehicles (EVs), internal combustion engines, and Hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV) , tracked vehicles in which these tires and wheels are converted into tracks, and motorized vehicles including electrically assisted bicycles. Bicycles, motorcycles, electric wheelchairs, golf carts, small or large boats, submarines, helicopters Examples include robots, aircraft, rockets, satellites, space probes, planetary probes, and spacecraft. do.

[0296] The semiconductor device or electronic component according to one aspect of the present invention is a communication device built into these electronic devices. It can be used in communication devices, etc.

[0297] Electronic devices include sensors (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid , magnetic, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, (including those that measure humidity, gradient, vibration, odor, or infrared rays) good.

[0298] Electronic devices can have various functions. For example, they can store various information (still images, videos, Functions for displaying text images, etc. on the display, touch panel function, calendar, date, or The function of the device is to display the time, run various software (programs), and The device has functions such as transmitting and receiving data, and reading programs or data recorded on a recording medium. This can be done.

[0299] An example of an electronic device is shown in Fig. 18 and Figs. 19A to 19F. The device 8000 is an example of an electronic device including a semiconductor device 8004 according to one embodiment of the present invention. Specifically, the display device 8000 corresponds to a display device for receiving TV broadcasts, and has a housing 8001 , a display portion 8002, a speaker portion 8003, a semiconductor device 8004, a power storage device 8005, etc. The semiconductor device 8004 according to one embodiment of the present invention is provided inside the housing 8001. The semiconductor device 8004 can store control information, control programs, etc. In addition, the semiconductor device 8004 has a communication function, and the display device 8000 can be used as an IoT device. The display device 8000 can function by receiving power from a commercial power source. Alternatively, power stored in the power storage device 8005 can be used.

[0300] The display unit 8002 is a display device having a light emitting element such as a liquid crystal display device or an organic EL element in each pixel. Optical display devices, electrophoretic display devices, DMD (Digital Micromirror Display) device), PDP (Plasma Display Panel), FED (Fie A display device such as a 100% Emission Display can be used.

[0301] In addition to TV broadcast reception, display devices are also used for personal computers and advertising displays. This includes all display devices for displaying information, such as:

[0302] In FIG. 18, a stationary lighting device 8100 is a semiconductor device according to one embodiment of the present invention. 8103. Specifically, the lighting device 8100 is an example of an electronic device using the housing 8101. 18, the semiconductor device 8103 includes a light source 8102, a semiconductor device 8103, a power storage device 8105, and the like. The conductor device 8103 is attached to the ceiling 8104 on which the housing 8101 and the light source 8102 are installed. Although the semiconductor device 8103 is shown as being provided inside the housing 8101, The semiconductor device 8103 can improve the brightness of the light source 8102. The semiconductor device 8103 can store information, control programs, etc. This allows the lighting device 8100 to function as an IoT device. The lighting device 8100 can receive power from a commercial power source or can receive power stored in a power storage device. The generated power can also be used.

[0303] In addition, FIG. 18 illustrates a lighting device 8100 of a fixed type provided on a ceiling 8104. However, in the semiconductor device according to one embodiment of the present invention, the sidewall 8405, It can also be used in a fixed lighting device installed on a floor 8406, a window 8407, etc. It can also be used as a tabletop lighting device.

[0304] The light source 8102 can be an artificial light source that artificially obtains light using electricity. Specifically, this applies to incandescent lamps, discharge lamps such as fluorescent lamps, and light-emitting devices such as LEDs and organic EL elements. An example of the artificial light source is a light element.

[0305] In FIG. 18, an air conditioner having an indoor unit 8200 and an outdoor unit 8204 8 illustrates an example of an electronic device including a semiconductor device 8203 according to one embodiment of the present invention. The indoor unit 8200 includes a housing 8201, an air outlet 8202, a semiconductor device 8203, a power storage device 8204, and a power supply 8205. 18, the semiconductor device 8203 is provided in an indoor unit 8200. However, the semiconductor device 8203 may be provided in an outdoor unit 8204. Alternatively, the semiconductor device 8203 may be provided in both the indoor unit 8200 and the outdoor unit 8204. The semiconductor device 8203 may be used to transmit control information for an air conditioner and a control program. The semiconductor device 8203 has a communication function and can store programs. Air conditioners can function as IoT devices. The power supply can be supplied from a commercial power source, and the power can be stored in the power storage device 8205. The generated power can also be used.

[0306] In addition, Figure 18 shows a separate type air conditioner consisting of an indoor unit and an outdoor unit. However, it is an integrated air conditioner that has the functions of both an indoor unit and an outdoor unit in a single housing. The semiconductor device according to one embodiment of the present invention can be used for the conditioner.

[0307] In FIG. 18, an electric refrigerator-freezer 8300 includes a semiconductor device 830 according to one embodiment of the present invention. 8301. Specifically, the electric refrigerator-freezer 8300 is an example of an electronic device using the housing 8301. , a refrigerator door 8302, a freezer door 8303, a semiconductor device 8304, a power storage device 8305, etc. In FIG. 18, a power storage device 8305 is provided inside a housing 8301. The semiconductor device 8304 controls the electric refrigerator-freezer 8300 and stores control information and a control program. The semiconductor device 8304 has a communication function, and can The 8300 can function as an IoT device. The power storage device 8305 can receive power from a commercial power source or can use the power stored in the power storage device 8305. Force can also be used.

[0308] FIG. 19A shows an example of a wristwatch-type mobile information terminal. 101, a display unit 6102, a band 6103, an operation button 6105, etc. The portable information terminal 6100 includes a secondary battery and a semiconductor device or a The semiconductor device or electronic component according to one aspect of the present invention is provided in a portable information terminal 61. By using this in the mobile information terminal 6100, it is possible to function as an IoT device. do.

[0309] 19B shows an example of a mobile phone. A mobile information terminal 6200 includes a housing 6201 In addition to the display unit 6202 incorporated in the It is equipped with a Rophone 6205 and other instruments.

[0310] The portable information terminal 6200 also has a fingerprint sensor 6209 in an area overlapping the display unit 6202. The fingerprint sensor 6209 may be an organic optical sensor. Fingerprints are unique to each individual. Therefore, the fingerprint sensor 6209 can acquire a fingerprint pattern and perform personal authentication. The light emitted from the display unit 6202 is used as a light source for acquiring a fingerprint pattern by the fingerprint sensor 6209. The light generated can be used.

[0311] The portable information terminal 6200 includes a secondary battery and a semiconductor device according to one embodiment of the present invention. The semiconductor device or electronic component according to one aspect of the present invention is provided as a portable information device. By using the information terminal 6200, the mobile information terminal 6200 functions as an IoT device. It is possible.

[0312] 19C shows an example of a cleaning robot. The cleaning robot 6300 is housed in a housing 630 1, a display unit 6302 arranged on the top surface, a plurality of cameras 6303 arranged on the side, and a brush 6 304, an operation button 6305, various sensors, etc. Although not shown, the cleaning robot The cleaning robot 6300 is equipped with tires, a suction nozzle, etc. It moves, detects dust 6310, and sucks up the dust from the suction port on the bottom. Cut.

[0313] For example, the cleaning robot 6300 analyzes the image captured by the camera 6303 and detects the walls, furniture, etc. It can also determine whether there are obstacles such as steps. If an object that is likely to get tangled in the brush 6304 is detected, the rotation of the brush 6304 is stopped. The cleaning robot 6300 includes a secondary battery and a battery according to one embodiment of the present invention. The semiconductor device or electronic component according to one aspect of the present invention is provided. By using it in the Cleaning Robot 6300, the Cleaning Robot 6300 can function as an IoT device. It can be done.

[0314] Figure 19D shows an example of a robot. The robot 6400 shown in Figure 19D performs the following operations: Device 6409, illuminance sensor 6401, microphone 6402, upper camera 6403, A speaker 6404, a display unit 6405, a lower camera 6406 and an obstacle sensor 6407, It is equipped with a moving mechanism 6408.

[0315] The microphone 6402 has the function of detecting the user's voice and environmental sounds. The speaker 6404 has a function of emitting sound. Use the microphone 6402 and speaker 6404 to communicate with the user. It is possible to do this.

[0316] The display unit 6405 has a function of displaying various information. The display unit 6405 can display information desired by the user. The display unit 6405 may be a detachable information terminal. By placing it in a fixed position on the robot 6400, charging and data transfer can be performed. This makes it possible.

[0317] The upper camera 6403 and the lower camera 6406 capture images of the surroundings of the robot 6400. The obstacle sensor 6407 also detects the obstacles by using the moving mechanism 6408. Robot 6 can detect the presence or absence of obstacles in its path as it moves forward. 400 uses an upper camera 6403, a lower camera 6406, and an obstacle sensor 6407. The light-emitting device according to one embodiment of the present invention can recognize the surrounding environment and move safely. can be used for the display portion 6405.

[0318] The robot 6400 includes a secondary battery and a semiconductor device or The semiconductor device or electronic component according to one embodiment of the present invention is provided by a robot 6400. By using this, the robot 6400 can function as an IoT device.

[0319] FIG. 19E shows an example of an air vehicle. The air vehicle 6500 shown in FIG. 19E has a propeller. 6501, a camera 6502, and a battery 6503, and has the capability to fly autonomously. It has.

[0320] For example, image data captured by the camera 6502 is stored in the electronic component 6504. The child component 6504 analyzes image data and detects whether there are any obstacles when moving. Also, the electronic component 6504 can detect the change in the storage capacity of the battery 6503. The flying object 6500 has a battery remaining capacity according to an embodiment of the present invention. The semiconductor device or electronic component according to one aspect of the present invention includes: By using this in the Air Vehicle 6500, the Air Vehicle 6500 can function as an IoT device. can be done.

[0321] FIG. 19F shows an example of a car. The car 7160 has an engine, tires, brakes, and The car 7160 has a brake, a steering device, a camera, etc. The car 7160 has a vehicle interior according to one embodiment of the present invention. The present invention relates to a semiconductor device or electronic component. By using this product in a car 7160, the car 7160 can function as an IoT device. This can be done.

[0322] The configurations, structures, methods, etc. shown in this embodiment may be the same as those shown in other embodiments. It can be used in combination with other methods as appropriate.

[0323] (Sixth embodiment) The OS transistors described in this specification and the like are used to realize normally-off CPUs ("Noff"). It is also called "Noff-CPU". Normally-off transistors are non-conducting (also called off-state) even when the voltage is 0V. It is an integrated circuit containing a resistor.

[0324] The Noff-CPU stops supplying power to circuits that are not required to operate. The circuit can be put into a standby state. When the power supply is stopped and the circuit is in a standby state, No power is consumed. Therefore, the Noff-CPU can minimize power consumption. In addition, the Noff-CPU can maintain the settings and other necessary functions even if the power supply is cut off. It can retain information for a long period of time. When it returns from standby mode, the power supply to the circuit is resumed. It is only necessary to reset the standby state, and there is no need to rewrite the setting conditions. In this way, the No-off CPU can recover quickly without significantly slowing down its operation speed. This significantly reduces power consumption.

[0325] Noff-CPU is used in the IoT (Internet of Things) field, for example. IoT end devices (also called "endpoint microcomputers") 803 and other small-scale systems It can be suitably used for

[0326] Figure 20 shows the hierarchical structure of IoT networks and the trend of required specifications. The power consumption 804 and processing performance 805 are shown as examples. It is roughly divided into the cloud field 801, which is the upper layer, and the embedded field 802, which is the lower layer. The cloud field 801 includes, for example, servers. The embedded field 802 includes, for example, machines. , industrial robots, automotive equipment, home appliances, etc.

[0327] The higher the layer, the more important it is to have high processing performance rather than low power consumption. In 801, high-performance CPUs, high-performance GPUs, large-scale SoCs, etc. are used. Low power consumption is required rather than high processing performance, and the number of devices is increasing explosively. The semiconductor device according to one embodiment of the present invention is suitable for use in a communication device of an IoT terminal device that requires low power consumption. It can be used appropriately.

[0328] The term "endpoint" refers to the terminal area of ​​the embedded field 802. The devices used in this project are, for example, those used in factories, home appliances, infrastructure, agriculture, etc. This applies to microcontrollers.

[0329] Figure 21 shows an example of an application of an endpoint microcontroller in factory automation. The factory 884 is connected to the cloud via the Internet. Cloud 883 is also connected to Home 8 via the Internet. 81 and office 882. The internet line is a wired communication system. For example, in the case of a wireless communication system, the communication device may include the The semiconductor device according to the present invention can be used to implement a fourth generation mobile communication system (4G) or a fifth generation mobile communication system. Wireless communication can be performed in accordance with communication standards such as the 5G mobile communication system. 84 may be connected to a factory 885 and a factory 886 via an internet line.

[0330] The factory 884 has a master device (control device) 831. The master device 831 It has a function to connect to the cloud 883 and send and receive information. The IoT terminal device 841 includes multiple industrial robots 842, and M2M (Mach The M2M interface is connected via a Machine to Machine (M2M) interface 832. The interface 832 may be, for example, an industrial Ethernet ( "Ethernet" is a registered trademark) and local 5G, a type of wireless communication method. Good too.

[0331] Factory managers can manage the factory from home 881 or office 882 via cloud 883. You can connect to the site 884 to check the operation status. It is possible to give location instructions, measure takt time, etc.

[0332] In recent years, the introduction of IoT into factories has been progressing worldwide, calling them "smart factories." In the case of smart factories, it is not just inspection and audit using endpoint microcomputers, Cases have been reported in which it has also been used to detect faults and predict abnormalities.

[0333] Small-scale systems such as endpoint microcontrollers consume a large amount of power during operation. Since the power consumption is often small, the power saving effect of the Noff-CPU during standby operation is large. On the other hand, in the embedded field of IoT, quick response is sometimes required, but Noff-CP By using U, high-speed recovery from standby operation can be achieved.

[0334] The configurations, structures, methods, and the like shown in this embodiment may be the same as those shown in other embodiments. It can be used in combination with other methods as appropriate.

[0335] (Notes regarding the present specification) The following additional notes will be given regarding the above-described embodiments and the respective configurations in the embodiments. .

[0336] The configurations shown in each embodiment may be appropriately combined with the configurations shown in other embodiments to realize the present invention. In addition, in one embodiment, multiple configuration examples may be shown. In this case, the configuration examples can be combined as appropriate.

[0337] It should be noted that the contents (or even a part of the contents) described in one embodiment may be used in the implementation of the embodiment. Another content (or part of the content) described in the form, and / or one or more other The contents (or a part of the contents) described in the embodiment of the present invention may be applied, combined, or You can make substitutions etc.

[0338] The contents described in the embodiments are explained using various drawings in each embodiment. This refers to the content stated in the specification or the content stated using the text in the specification.

[0339] In addition, a drawing (or a part thereof) described in one embodiment may be replaced with another part of the drawing. Another figure (or a part thereof) described in the embodiment, and / or one or more The figures (or a part thereof) described in a plurality of different embodiments may be combined. allows for the construction of even more diagrams.

[0340] In addition, in the block diagrams in this specification, components are classified by function and are independent of each other. However, in actual circuits, the components are divided into functional blocks. It is difficult to separate the functions into separate parts, and there are cases where multiple functions are involved in one circuit, or where a circuit is involved in multiple circuits. Therefore, the blocks in the block diagram may be The present invention is not limited to the components described above, and may be rephrased appropriately depending on the situation.

[0341] In addition, in the drawings, the size, layer thickness, and area are arbitrarily scaled for convenience of explanation. Therefore, the drawings are not necessarily limited to the scale. The drawings are merely schematic illustrations for the sake of convenience, and are not limited to the shapes or values ​​shown in the drawings. For example, variations in signal, voltage, or current due to noise, or timing deviations. This may include variations in signal, voltage, or current due to the

[0342] In addition, the positional relationships of the components shown in the drawings are relative. When describing components by reference, the terms "above" and "below" that indicate positional relationships are used for convenience. The positional relationship of the components is not limited to the contents described in this specification, and may vary depending on the situation. It can be rephrased appropriately depending on the situation.

[0343] In this specification and the like, when describing the connection relationship of a transistor, the term "source or drain" is used. The other of the source and drain is called the "source or drain" (or first electrode, or first terminal). The term "the other of the drain and the second electrode" is used. The source and drain of a transistor vary depending on the structure or operating conditions of the transistor. The source and drain of a transistor are called the source (drain) In (in) terminal, source (drain) electrode, etc., depending on the situation. .

[0344] In addition, the terms "electrode" and "wiring" used in this specification and the like refer to these components functionally. This is not a limitation. For example, an "electrode" may be used as part of a "wiring." , and vice versa. Furthermore, the terms "electrode" and "wiring" may be used interchangeably with "electrodes" and "wiring." This also includes cases where the wiring is formed integrally.

[0345] In this specification and the like, the terms voltage and potential can be interchanged as appropriate. The potential difference from the reference potential. For example, the reference potential is the ground voltage (earth If we use the term "voltage", we can translate voltage into potential. Ground potential is not necessarily 0V. It does not necessarily mean that the potential is relative, and depending on the reference potential, The potential applied to wiring etc. may be changed.

[0346] In this specification, a node may be a terminal, a wiring, or the like depending on a circuit configuration, a device structure, or the like. The term "electrode," "conductive layer," "conductor," "impurity region," etc. may also be used. Lines and the like can be referred to as nodes.

[0347] In this specification, "A and B are connected" means that A and B are electrically connected. Here, A and B are electrically connected to each other. Objects (switches, transistor elements, diodes, etc.), or the elements and A connection that allows transmission of electrical signals between A and B when there is a circuit (including wiring, etc.) If A and B are electrically connected, it is considered that A and B are directly connected. Here, A and B being directly connected means that they are connected via the above object. Instead, electrical signals can be transmitted between A and B via wiring (or electrodes) etc. In other words, a direct connection is a connection that can be seen as the same circuit diagram when expressed as an equivalent circuit. This refers to the connection that can be made.

[0348] In this specification, a switch refers to a device that can be in a conducting state (ON state) or a non-conducting state (OFF state). It refers to a device that has the function of controlling whether or not current flows by entering a state where it is in a non-operating state. A switch is a device that has the function of selecting and switching a path through which a current flows.

[0349] In this specification and the like, the channel length is, for example, the length of a semiconductor the body (or the part of the semiconductor through which current flows when the transistor is on) and the gate The distance between the source and drain in the region where they overlap or where the channel is formed. It means separation.

[0350] In this specification, the channel width is, for example, the width of a semiconductor (or a transistor) when it is in an on state. The area where the gate electrode overlaps with the gate electrode (the area where current flows in the semiconductor when the gate electrode is in the non-transistor state), or the channel The length of the portion where the source and drain face each other in the region where the capacitor is formed. .

[0351] In this specification, the terms "film" and "layer" are used in some cases or in other situations. For example, the term "conductive layer" can be used interchangeably with " It may be possible to change the term to "conductive film." In some cases, the term "insulating layer" can be changed to the term "insulating layer." [Explanation of symbols]

[0352] 10: wireless communication device, 100: semiconductor device, 101: current-voltage conversion unit, 102: current switch switch section, 103: voltage-current conversion section, 111: transistor, 112: semiconductor layer, 121: Transistor, 122: Semiconductor layer

Claims

1. a current-voltage conversion unit; a current switch unit; a voltage-current converter; a control unit; the current switch unit includes a first transistor and a second transistor, the voltage-current converter includes a third transistor; the control unit includes a fourth transistor; the first transistor has an oxide semiconductor in a channel formation region; the second transistor has an oxide semiconductor in a channel formation region; the third transistor has a nitride semiconductor in a channel formation region, the fourth transistor has silicon in a channel formation region; the first transistor is provided in a layer above a layer in which the third transistor and the fourth transistor are provided; the second transistor is provided in a layer above the layer in which the first transistor is provided; Semiconductor device.

2. In claim 1, The semiconductor device, wherein the oxide semiconductor contains In, Ga, and Zn.

3. In claim 1 or claim 2, The nitride semiconductor device includes Ga.

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