Solid-state secondary batteries

Abstract

To provide an all-solid secondary battery having higher safety than a conventional lithium ion secondary battery using an electrolytic solution, specifically, a thin film type solid secondary battery, and to provide a method of manufacturing the same.SOLUTION: A mixed material obtained by co-evaporation of SiO and an organic complex of lithium is used as a solid electrolyte. That is, a solid electrolyte layer formed using a mixed material of an inorganic material and an organic material is used for the solid secondary battery. The ratio of oxygen to silicon in the solid electrolyte layer is greater than 1 and less than 2.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] One aspect of the present invention relates to a product, a method, or a method of manufacture. Alternatively, the present invention relates to a process. This relates to machines, manufacturers, or compositions of matter. One aspect of the present invention relates to semiconductor devices, display devices, light-emitting devices, energy storage devices, lighting devices, or electronic devices. This relates to vessels or methods for manufacturing them.

[0002] In this specification, "electronic equipment" refers to all devices that have an energy storage device. Electro-optical devices and information terminal devices with energy storage devices are all electronic devices. [Background technology]

[0003] There is a great deal of development going on in electronic devices that users carry with them and electronic devices that users wear on their devices.

[0004] Electronic devices carried by users or worn by users are examples of primary energy storage devices. It operates using batteries or rechargeable batteries as a power source. Electronic devices carried by the user are intended for long-term use. It is desirable to do so, and for that purpose, a large-capacity secondary battery should be used. When a battery is built in, high-capacity rechargeable batteries become large and heavy, which is a problem. Development is underway to create small, thin, and high-capacity rechargeable batteries that can be built into electronic devices.

[0005] A liquid such as an organic solvent is used as a medium to move lithium ions, which are carrier ions. Lithium-ion secondary batteries, which use liquid, are widely used. However, secondary batteries that use liquid In this case, since a liquid is used, there are issues with the decomposition reaction of the electrolyte depending on the operating temperature range and operating potential. There are problems such as leakage outside the battery and the problem of liquid leakage from the secondary battery. In addition, secondary batteries using a liquid electrolyte have a risk of ignition due to liquid leakage.

[0006] There is a fuel cell as a secondary battery that does not use a liquid, but it is a device that uses a noble metal for the electrode and has an expensive material for the solid electrolyte.

[0007] In addition, there is a power storage device called a solid battery that uses a solid electrolyte as a secondary battery that does not use a liquid. For example, Patent Document 1, Patent Document 2, etc. are disclosed. Also, Patent Document 3 describes using any one of a solvent, a gel, or a solid electrolyte for the electrolyte of a lithium-ion secondary battery.

[0008] Patent Document 1 describes an example of forming a lithium cobaltate film on a positive electrode current collector by a sputtering method.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0010] To provide an all-solid-state secondary battery with higher safety than a conventional lithium-ion secondary battery using an electrolytic solution, specifically, a thin-film type solid secondary battery (also called a thin-film all-solid-state battery) and a method for manufacturing the same.

[0011] ​​​​​​​Another problem is to provide a new material as a solid electrolyte used in a thin-film solid secondary battery. This is one of them.

[0012] Another problem is to provide an all-solid-state secondary battery suitable as a secondary battery used in a thin electronic device such as a card terminal. This is also one of the problems.

[0013] Another problem is to provide an all-solid-state secondary battery suitable as a secondary battery used in a wearable device, specifically a small electronic device in the form of a wristwatch, or a secondary battery used in a small electronic device in the form of glasses. In particular, in a wearable device, since it may come into contact with the user's skin, it is desirable to use an all-solid-state secondary battery with high safety that does not cause liquid leakage or the like. This is one of the problems.

Means for Solving the Problems

[0014] (0 < X < 2) and an organic complex of lithium as a solid electrolyte. That is, it is one of the features of the present invention to use a solid electrolyte layer made of a mixed material of an inorganic material and an organic material in a solid secondary battery. (0 < X < 2) as the material to be co-evaporated with can be any of a simple substance of an alkali metal or an alkaline earth metal, an organic complex or a compound. For example, Li, Li2O, etc. can be mentioned. In particular, an organic complex of lithium is preferable, and among them, 8-hydroxyquinolinato-lithium (abbreviation: Liq) is preferable. One of the configurations related to the manufacturing method disclosed in this specification is that on the positive electrode active material layer or the negative electrode active material layer, an organic complex of lithium and SiO

[0015] SiO X (0 < X < 2) and the material to be co-evaporated with can be any of a simple substance of an alkali metal or an alkaline earth metal, an organic complex or a compound. For example, Li, Li2O, etc. can be mentioned. In particular, an organic complex of lithium is preferable, and among them, 8-hydroxyquinolinato-lithium (abbreviation: Liq) is preferable. One of the configurations related to the manufacturing method disclosed in this specification is that on the positive electrode active material layer or the negative electrode active material layer, an organic complex of lithium and SiO In particular, an organic complex of lithium is preferable, and among them, 8-hydroxyquinolinato-lithium (abbreviation: Liq) is preferable.

[0016] One of the configurations related to the manufacturing method disclosed in this specification is that on the positive electrode active material layer or the negative electrode active material layer, an organic complex of lithium and SiO X ​(0 < X < 2) is co-evaporated to form a solid electrolyte layer This is a method for manufacturing a solid secondary battery.

[0017] In the above manufacturing method, since the positive electrode and the negative electrode are formed by sputtering, it is preferable that the positive electrode active material layer or the negative electrode active material layer is formed by sputtering. The sputtering apparatus can also perform continuous film formation using the same chamber or multiple chambers, and can be a multi-chamber type manufacturing apparatus or an in-line type manufacturing apparatus. The sputtering method is a manufacturing method suitable for mass production using a chamber and a sputtering target. Also, the sputtering method can form thin films and has excellent film formation characteristics.

[0018] Also, it is not particularly limited to the sputtering method, and the positive electrode active material layer or the negative electrode active material layer can also use a vapor phase method (vacuum evaporation method, spraying method, pulsed laser deposition method (PLD method), ion plating method, coater spray method, aerosol deposition method). Note that the aerosol de position (AD) method is a method of forming a film without heating the substrate. An aerosol refers to fine particles dispersed in a gas.

[0019] Also, the positive electrode, negative electrode, positive electrode active material layer, or negative electrode active material layer may be formed using the CVD method or the ALD (Atomic layer Deposition) method.

[0020] Also, a solid secondary battery can be manufactured by laminating the material films obtained by the above manufacturing method.

[0021] The obtained solid secondary battery is also one of the present inventions, and its configuration includes a positive electrode, a negative electrode, and a solid electrolyte layer having silicon, oxygen, lithium, and carbon between the positive electrode and the negative electrode.

[0022] In the above configuration, the solid electrolyte layer further contains nitrogen. This nitrogen is part of the lithium organic complex. This is caused by nitrogen in the body.

[0023] Furthermore, in the above configuration, a negative electrode active material layer containing silicon is provided between the negative electrode and the solid electrolyte layer. The negative electrode active material layer is deposited using a sputtering target primarily composed of silicon. It is possible.

[0024] Furthermore, in the above configuration, a positive electrode active material layer is provided between the positive electrode and the solid electrolyte layer. The formation layer is primarily composed of lithium cobalt oxide (LiCoO2) sputtering target A film can be formed using a tactile palatine.

[0025] The silicon-to-oxygen ratio (O / Si) in the solid electrolyte layer is greater than 1 and less than 2. That is, The ratio of oxygen to silicon in the solid electrolyte layer is greater than 1 and less than 2. By creating a surrounding enclosure, lithium ions can easily diffuse, and the solid electrolyte has no electronic conductivity. It can be achieved.

[0026] To improve the lithium ion conductivity of the solid electrolyte, phosphorus or other elements may be added. stomach.

[0027] In this specification, the oxygen ratio of the solid electrolyte layer described above is based on the value obtained by EDX measurement. I'll do that.

[0028] EDX measurement is a method of measuring while scanning within a region and evaluating that region in two dimensions. This is sometimes called X-plane analysis. Furthermore, data from linear regions is extracted from EDX plane analysis, and the original The process of evaluating the distribution of particle concentration within the positive electrode active material particles is sometimes called linear analysis.

[0029] By EDX surface analysis (e.g., elemental mapping), the concentrations of silicon, nitrogen, carbon, and oxygen in the interior or surface layer can be quantitatively analyzed. Also, by EDX line analysis, the peaks of the concentrations of silicon, nitrogen, carbon, and oxygen can be analyzed. The unit of the EDX concentration is, for example, atomic %.

Advantages of the Invention

[0030] As a solid electrolyte layer, a thin film formed by co-evaporating an organic complex of lithium and SiO(0 < X < 2) enables the production of a thin-film type solid secondary battery. X (0 < X < 2) and

[0031] Since no electrolytic solution is used, the thin-film type solid secondary battery has heat resistance such that it can be used even at high temperatures.

[0032]

[0033] Also, the thin-film type solid secondary battery can be multilayered by increasing the number of laminations with one set consisting of a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in series or parallel connection, thereby increasing the capacity. [[ID=3{3]]

[0034] Also, the capacity of the thin-film type solid secondary battery can be increased by increasing the area.

[0035] [Figure 1] [Figure 2] [Figure 3]

Brief Description of the Drawings

[0036] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is... Not limited to the following description, the form and details can be modified in various ways, as any person skilled in the art would know. This is easily understood. Furthermore, the present invention shall be interpreted as being limited to the contents of the embodiments described below. It's not something that can be done.

[0037] (Embodiment 1) Figure 1 shows an embodiment for a single-layer cell of a thin-film solid-state secondary battery. It is one of the states. In this specification, a single-layer cell of a solid-state secondary battery refers to a positive electrode, a solid electrode This refers to a set of units having at least a decomposition layer and a negative electrode.

[0038] The single-layer cell shown in Figure 1 consists of a positive electrode 201, a positive electrode active material layer 204, and a solid electrolyte layer on a substrate 101. The layers are stacked in the following order: 202, negative electrode active material layer 205, and negative electrode 203. Note the cross-section shown in Figure 1. The diagram shows only a portion of the arrangement; the plane area of ​​the positive electrode is smaller than the plane area of ​​the negative electrode. Furthermore, the ends are rounded, and only one end is shown in Figure 1.

[0039] The substrate 101 can be a ceramic substrate, a glass substrate, a plastic substrate, or a silicon substrate. Examples include metal substrates.

[0040] The materials for the positive electrode 201 and the negative electrode 203 include Al, Ti, Cu, Au, Cr, W, Mo, One or more conductive materials selected from Ni, Ag, etc. are used. The film deposition method is as follows: Sputtering and vapor deposition methods can be used. In addition, in the sputtering method, metal By using a screen, film deposition can be selectively performed. Alternatively, by using a resist mask, etc. By selectively removing the conductive film through dry etching or wet etching, the conductive film can be patinated. You may do so.

[0041] The positive electrode active material layer 204 is lithium cobalt oxide (LiCoO2, LiCo2O4, etc.). Sputtering targets mainly composed of, and lithium manganese oxide (LiMnO2, Sputtering targets mainly composed of LiMn2O4, etc., and lithium nickel acid Thin films can be deposited by sputtering using alloys (such as Li with O2, LiNi2O4, etc.). Also, lithium manganese cobalt oxide (LiMnCoO4, Li2MnCoO4) (d) Ternary materials of nickel, cobalt, and manganese (LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O 2: NCM), ternary materials of nickel, cobalt, and aluminum (LiNi 0.8 Co 0.1 5Al 0.05 O2: NCA), etc. can also be used.

[0042] The solid electrolyte layer 202 uses a mixed material of an inorganic material and an organic material. In this embodiment, S iO X (0 < X < 2) and a mixed material obtained by co-evaporation with an organic complex of lithium are used.

[0043] SiO X (0 < X < 2) The material to be co-evaporated with can be any of a simple substance of an alkali metal or an alkaline earth metal, an organic complex, or a compound. For example, Li, Li2O, etc. can be cited . In particular, an organic complex of lithium is preferable. Among them, 8-hydroxyquinoline​​​​​​​​​​​​​​​​​​​​​​​​ Furthermore, the solid electrolyte layer 202 may be in a laminated structure, and in the case of a laminated structure, one layer may contain phosphate A material (Li3PO4) to which nitrogen has been added. 4-Y N Y Also called LiPON You can stack (which will be exposed). Note that Y > 0.

[0046] The negative electrode active material layer 205 is formed using sputtering or other methods, with silicon as the main component and carbon as the main component. The components of the film are titanium oxide film, vanadium oxide film, indium oxide film, zinc oxide film, and oxide A tin film, a nickel oxide film, etc., can be used. In addition, L can be used as the negative electrode active material layer 205. i Metal films may also be used. Furthermore, lithium titanium oxide (Li4Ti5O 12 LiTi You may also use 2O4 (or similar).

[0047] Thus, thin-film solid-state secondary batteries, by stacking various films, reduce interfacial resistance and internal resistance. It is preferable to reduce resistance. In addition, the surface uniformity and adhesion of each film should also be considered depending on the film it is in contact with. It is preferable to have an excellent combination.

[0048] Furthermore, the layers can be stacked in any order. Figure 2 shows an example of a different stacking order than that shown in Figure 1. This is shown in Figures A and 2B. Figure 2A is a top view, and Figure 2B is a cross view taken along line AA' in Figure 2A. It corresponds to the surface drawing.

[0049] As shown in Figure 2B, a negative electrode 203 is formed on the substrate 101, and a negative electrode active material is placed on the negative electrode 203. The layers are in the following order: layer 205, solid electrolyte layer 202, positive electrode active material layer 204, positive electrode 201, and protective layer 206. They are layered.

[0050] These films can each be formed using a metal mask. The negative electrode 203, negative electrode active material layer 205, positive electrode active material layer 204, positive electrode 201, and protective layer 206 It is sufficient to form it selectively. Furthermore, by using the co-evaporation method and a metal mask, solid electrolysis can be achieved. A solid electrolyte layer 202 is selectively formed. The solid electrolyte layer 202 is composed of Si powder (SiO) and Li powder The film is formed by co-deposition, where each end is deposited separately. Note that co-deposition is performed using a resistance heating source. Alternatively, an electron beam deposition source is used. Note that it is not limited to Si powder (SiO), but also pellets. You may use objects.

[0051] As shown in Figure 2A, a portion of the negative electrode 203 is exposed to form the negative electrode terminal. Negative electrode terminal The area other than the part is covered with a protective layer 206. Also, a part of the positive electrode 201 is exposed. It forms the electrode terminal portion. The area other than the positive electrode terminal portion is covered with a protective layer 206.

[0052] Furthermore, a silicon nitride film (also called a SiN film) is used as the protective layer 206. The film is deposited using the sputtering method.

[0053] The thin-film type solid-state secondary battery shown in Figure 2A can be manufactured through the above series of steps.

[0054] Furthermore, EDX surface analysis (e.g., elemental mapping) was performed on the obtained thin-film type solid secondary battery. By using this method, silicon, nitrogen, carbon in the interior or surface layer of the solid electrolyte layer 202 The concentrations of elements and oxygen can be quantitatively analyzed.

[0055] A solid electrolyte layer 202 was formed, and its EDX measurement was performed.

[0056] The EDX spectrum of the cross-section of the solid electrolyte layer 202 is described. In the EDX measurement, the measurement points The electron beam is irradiated, and the energy and number of occurrences of the characteristic X-rays generated are measured. The DX spectrum was obtained. The results are shown in Figure 3. The atomic number concentrations (%) are shown in Table 1.

[0057] [Table 1]

[0058] These results indicate that the obtained material allows lithium ions to diffuse easily and is electrically conductive. It is a material that does not contain any chemicals and can be used as a solid electrolyte.

[0059] Furthermore, the oxygen ratio of the solid electrolyte layer can be calculated based on the value obtained from EDX measurement. The silicon-to-oxygen ratio (O / Si) in the electrolyte layer is greater than 1 and less than 2. By setting the range to such an extent, lithium ions can diffuse easily, and the solid electrolytic material has no electronic conductivity. Quality can be achieved.

[0060] Furthermore, the deposition of solid electrolyte films is not limited to co-evaporation; it can also be carried out in the same chamber using SiO gas and Li By simultaneously generating gases and cooling them on the same surface to be deposited, film formation can be performed. It can also be done this way.

[0061] (Embodiment 2) While Embodiment 1 showed an example of a single-layer cell, this embodiment shows a multi-layer cell An example is shown. Figures 4 and 5 show an implementation for a multilayer cell of a thin-film solid-state secondary battery. It is one form.

[0062] Figure 4 shows an example of a cross-section of a three-layer cell.

[0063] A positive electrode 201 is formed on the substrate 101, and a positive electrode active material layer 204 and a solid electrolyte layer are formed on the positive electrode 201. The first cell is formed by sequentially forming 202, the negative electrode active material layer 205, and the negative electrode 203. They are doing it.

[0064] Furthermore, a second negative electrode active material layer, a second solid electrolyte layer, and a second positive electrode active material layer are placed on the negative electrode 203. The second cell is constructed by sequentially forming a material layer and a second positive electrode layer.

[0065] Furthermore, the third layer consists of a positive electrode active material layer, a solid electrolyte layer, and a negative electrode layer, all placed on top of the second layer of positive electrode. The third cell is formed by sequentially creating the active material layer and the third negative electrode layer.

[0066] In Figure 4, the protective layer 206 is formed last. The three-layer lamination shown in Figure 4 increases the capacity. Although it is configured to be connected in series, it can also be connected in parallel using external wiring. Furthermore, it is possible to select series, parallel, or series-parallel connections for external wiring.

[0067] Note that the solid electrolyte layer 202, the second solid electrolyte layer, and the third solid electrolyte layer are made of the same material. Using this method is preferable because it can reduce manufacturing costs.

[0068] Furthermore, Figure 5 shows an example of a manufacturing flow for obtaining the structure shown in Figure 4.

[0069] In Figure 5, to reduce the number of manufacturing steps, an LCO film is used as the positive electrode active material layer, and A titanium film is used as the electrochemical element, and the titanium film is considered the positive electrode. In addition, the negative electrode active material layer is A silicon film is used, and a titanium film is used as the current collector, which is considered the negative electrode. The titanium film is common. By using it as an electrode, a 3-layer stacked cell can be realized with a minimal configuration.

[0070] (Embodiment 3) Figure 6A is an external view of a thin-film type solid secondary battery. The secondary battery 913 is It has terminals 951 and 952. Terminal 951 is the positive terminal, and terminal 952 is the negative terminal. They are electrically connected.

[0071] Figure 6B is an external view of the battery control circuit. The battery control circuit shown in Figure 6B is located on a circuit board 900 mm. It has a layer 916. Circuits 912 and an antenna 914 are provided on the substrate 900. Antenna 914 is electrically connected to circuit 912. Circuit 912 has terminal 971 and terminal The child 972 is electrically connected. Circuit 912 is electrically connected to terminal 911.

[0072] Terminal 911 is connected to a device that is powered by, for example, a thin-film solid-state rechargeable battery. It is then connected to a display device, sensor, etc.

[0073] Layer 916 has the function of shielding electromagnetic fields, for example, from the secondary battery 913. For layer 916, for example, a magnetic material can be used.

[0074] Figure 6C shows an example where the battery control circuit shown in Figure 6B is placed on the secondary battery 913. Terminal 9 Terminal 71 is electrically connected to terminal 951, and terminal 972 is electrically connected to terminal 952. Layer 91 6 is positioned between the circuit board 900 and the secondary battery 913.

[0075] It is preferable to use a flexible substrate as the substrate 900.

[0076] By using a flexible substrate as substrate 900, a thin battery control circuit can be realized. This is possible. Also, as shown in Figure 7D later, the battery control circuit is wrapped around the secondary battery. It is possible.

[0077] Figure 7A is an external view of a thin-film solid-state secondary battery. The battery control circuit shown in Figure 7B is located on substrate 90 It has layers 0 and 916.

[0078] As shown in Figure 7C, the substrate 900 is bent to match the shape of the secondary battery 913, and the battery control circuit By arranging the battery control circuit around the secondary battery, as shown in Figure 7D, the battery control circuit is connected to the secondary battery It can be wrapped around it.

[0079] (Embodiment 4) This embodiment is applicable to the battery control circuit described in the above embodiment. This section explains the configuration of transistors. Specifically, it describes transistors with different electrical characteristics. A configuration in which layers are stacked will be described. By adopting this configuration, the design of the semiconductor device itself The degree of freedom can be increased. Also, transistors with different electrical characteristics can be stacked and provided. This allows for an increase in the integration density of semiconductor devices.

[0080] The semiconductor device shown in Figure 8 includes transistor 300, transistor 500, and capacitor 600. , has. Figure 10A is a cross-sectional view of transistor 500 in the channel length direction, and Figure 1 Figure 0B is a cross-sectional view of transistor 500 in the channel width direction, and Figure 10C is a cross-sectional view of transistor 3 This is a cross-sectional view of channel 00 in the channel width direction.

[0081] Transistor 500 is an OS transistor. Therefore, transistor 500 is OFF. Because the current is extremely low, by using this in the transistors of semiconductor devices, It is possible to retain the written data voltage or charge over a long period of time. In other words, The refresh operation is infrequent, or does not require a refresh operation, so The power consumption of the conductor device can be reduced.

[0082] The semiconductor device described in this embodiment includes a transistor 300, as shown in Figure 8. It has transistor 500 and capacitance 600. Transistor 500 is located above transistor 300. Capacitor 600 is provided above transistors 300 and 500. It is.

[0083] The transistor 300 is mounted on the substrate 311 and consists of a conductor 316, an insulator 315, and substrate 3 A semiconductor region 313 consisting of part of 11, a low that functions as a source region or drain region. It has a resistance region 314a and a low resistance region 314b.

[0084] As shown in Figure 10C, transistor 300 is located on the top surface and channel of semiconductor region 313. The sides in the width direction are covered by the conductor 316 via the insulator 315. In this way, By making the ZISTA 300 a Fin type, the effective channel width is increased. The ON characteristics of the transistor 300 can be improved. Also, the contribution of the electric field of the gate electrode. This allows for an increase in the off-peak characteristics of transistor 300. .

[0085] Note that transistor 300 can be either a p-channel or n-channel type.

[0086] The region where the channel of the semiconductor region 313 is formed, the region near it, the source region, or the do In the low-resistance region 314a and low-resistance region 314b, which are rain regions, silico It is preferable that the semiconductor contains semiconductors such as silicon-based semiconductors, and it is preferable that it contains single-crystal silicon. Alternatively, Ge (germanium), SiGe (silicon germanium), GaAs (galvanium) It may also be formed from materials containing arginine, GaAlAs (gallium aluminum arsenide), etc. By applying stress to the crystal lattice and changing the lattice spacing, silicon with controlled effective mass is produced. The configuration used may also be used. Alternatively, by using GaAs and GaAlAs, etc., the transient TA300 is HEMT (High Electron Mobility Transit) You can also use "tor)".

[0087] Low-resistance regions 314a and 314b are semiconductor regions applied to semiconductor region 313. In addition to the main material, elements that impart n-type conductivity, such as arsenic and phosphorus, or p-type conductivity, such as boron. It contains elements that impart conductivity.

[0088] The conductor 316, which functions as a gate electrode, is a component that imparts n-type conductivity, such as arsenic or phosphorus. Semiconductor materials such as silicon containing elements that impart p-type conductivity, such as boron or other elements. Conductive materials such as metallic materials, alloy materials, or metal oxide materials can be used.

[0089] Furthermore, since the work function is determined by the material of the conductor, by selecting the material of the conductor... This allows you to adjust the threshold voltage of the transistor. Specifically, titanium nitride is used as the conductor. It is preferable to use materials such as tannin or tantalum nitride. Furthermore, it is desirable to achieve both conductivity and embedding properties. To achieve this, metal materials such as tungsten and aluminum are used as laminates in the conductive material. This is preferable, and using tungsten is particularly preferable in terms of heat resistance.

[0090] Note that the transistor 300 shown in Figure 8 is just one example, and its structure is not limited to that example; the circuit configuration and other factors may also be considered. The appropriate transistor should be used depending on the driving method. For example, a semiconductor device can use an OS transistor. Unipolar circuits consisting only of transistors (e.g., only n-channel transistors, or transistors of the same polarity). If this means that, then as shown in Figure 9, the configuration of transistor 300 is such that oxide semiconductor The transistor 500, which uses a body, should have the same configuration. Details about 0 will be discussed later.

[0091] The transistor 300 is covered by insulators 320, 322, 324, and insulation. The bodies 326 are arranged in a series of stacked units.

[0092] As insulators 320, 322, 324, and 326, for example, oxidative Silicon, silicon oxide nitride, silicon nitride, silicon nitride, aluminum oxide, acid Aluminum nitride, aluminum nitride oxide, aluminum nitride, etc., can be used.

[0093] In this specification, silicon oxidnitride refers to a material whose composition contains more oxygen than nitrogen. This refers to materials with a high concentration of nitrogen, and silicon nitride, in its composition, has a higher nitrogen content than oxygen. This indicates a material in large quantities. Furthermore, in this specification, aluminum oxide nitride refers to its composition This refers to a material with a higher oxygen content than nitrogen, and aluminum nitride oxide is a material whose composition This refers to materials with a higher nitrogen content than oxygen content.

[0094] The insulator 322 smooths out the step created by the transistor 300 and the like located below it. It may also function as a planarizing film that flattens. For example, the upper surface of the insulator 322 is flat To improve its flexibility, it is planarized using a planarization treatment such as chemical mechanical polishing (CMP). It's okay to be there.

[0095] Furthermore, the insulator 324 receives transistors from the substrate 311 or transistors 300, etc. A barrier film is used in the region where the TA500 is provided to prevent the diffusion of hydrogen and impurities. It is preferable that they be present.

[0096] As an example of a film that has barrier properties against hydrogen, for example, silica nitride formed by CVD. A semiconductor having an oxide semiconductor such as transistor 500 can be used. The diffusion of hydrogen into the element may degrade the characteristics of the semiconductor element. Therefore, A film that suppresses hydrogen diffusion is used between transistor 500 and transistor 300. It is preferable to have one. Specifically, a membrane that suppresses hydrogen diffusion is one that minimizes hydrogen desorption. It will form a membrane.

[0097] The amount of hydrogen desorbed can be analyzed, for example, using a thermodynamic desorption gas analysis (TDS) method. For example, the amount of hydrogen desorption from insulator 324 is determined in TDS analysis when the film surface temperature is 5 In the range of 0°C to 500°C, the amount of desorption converted to hydrogen atoms is per unit area of ​​insulator 324. Convert to units, 10 x 10 15 atoms / cm 2 The following is preferably 5 × 10 15 at oms / cm 2 The following is acceptable.

[0098] Furthermore, it is preferable that the dielectric constant of the insulator 326 is lower than that of the insulator 324. For example, insulation The relative permittivity of body 326 is preferably less than 4, and more preferably less than 3. Also, for example, insulator 3 The relative permittivity of 26 is preferably 0.7 times or less the relative permittivity of the insulator 324, and preferably 0.6 times or less. More preferable. By using a material with a low dielectric constant as the interlayer film, parasitic capacitance between wirings can be reduced. It is possible.

[0099] In addition, insulators 320, 322, 324, and 326 have a capacity of 600. , or a conductor 328 and a conductor 330, etc., which are connected to transistor 500 are embedded. It is provided. Furthermore, conductors 328 and 330 function as plugs or wires. It has. In addition, a conductor that functions as a plug or wiring combines multiple structures. In some cases, the same symbol may be assigned to them. Also, in this specification, etc., wiring and connections to wiring The plug and the conductor may be integrated into a single unit. That is, when a part of the conductor functions as wiring. In some cases, a portion of the conductor may also function as a plug.

[0100] The materials for each plug and wiring (conductor 328, conductor 330, etc.) are metal materials, composite materials, etc. A conductive material such as gold material, metal nitride material, or metal oxide material is used in a single layer or in a multi-layered configuration. It can be used with high-melting-state materials such as tungsten and molybdenum, which offer both heat resistance and conductivity. It is preferable to use a point material, and it is preferable to use tungsten. Alternatively, aluminum It is preferable to form it with a low-resistance conductive material such as nium or copper. This can lower the wiring resistance.

[0101] A wiring layer may be provided on the insulator 326 and the conductor 330. For example, in Figure 8 Insulators 350, 352, and 354 are arranged in a sequential stack. Furthermore, a conductor 356 is formed on insulators 350, 352, and 354. Conductor 356 functions as a plug or wire connecting to transistor 300. It has the same material as conductors 328 and 330. It can be established.

[0102] For example, insulator 350 has a barrier property against hydrogen, similar to insulator 324. It is preferable to use an insulator. Furthermore, the conductor 356 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 350 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0103] For example, tantalum nitride can be used as a conductor that has barrier properties against hydrogen. This is good. Also, by laminating tantalum nitride and highly conductive tungsten, the wiring can be This allows for the suppression of hydrogen diffusion from transistor 300 while maintaining conductivity. In this case, the tantalum nitride layer having barrier properties against hydrogen provides a barrier against hydrogen. It is preferable that the structure is in contact with the insulator 350.

[0104] A wiring layer may be provided on the insulator 354 and the conductor 356. For example, in Figure 8 Insulators 360, 362, and 364 are arranged in a series of layers. Furthermore, a conductor 366 is formed on insulators 360, 362, and 364. Conductor 366 has the function of a plug or wiring. It can be provided using the same material as conductors 328 and 330.

[0105] For example, insulator 360 has a barrier property against hydrogen, similar to insulator 324. It is preferable to use an insulator. Furthermore, the conductor 366 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 360 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0106] A wiring layer may be provided on the insulator 364 and the conductor 366. For example, in Figure 8 Insulators 370, 372, and 374 are arranged in a sequential stack. Furthermore, a conductor 376 is formed on insulators 370, 372, and 374. It is present. Conductor 376 has the function of a plug or wiring. Note that Conductor 376 is It can be provided using the same material as conductors 328 and 330.

[0107] For example, insulator 370 has a barrier property against hydrogen, similar to insulator 324. It is preferable to use an insulator. Furthermore, the conductor 376 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 370 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0108] A wiring layer may be provided on the insulator 374 and the conductor 376. For example, in Figure 8 Insulators 380, 382, ​​and 384 are arranged in a sequential stack. Furthermore, a conductor 386 is formed on insulators 380, 382, ​​and 384. Conductor 386 functions as a plug or wiring. It can be provided using the same material as conductors 328 and 330.

[0109] For example, insulator 380 has a barrier property against hydrogen, similar to insulator 324. It is preferable to use an insulator. Furthermore, the conductor 386 has barrier properties against hydrogen. It is preferable that it contains a conductor. In particular, the insulator 380 having barrier properties against hydrogen is preferable. A conductor having a barrier property against hydrogen is formed in the opening. With this configuration, Transistor 300 and transistor 500 can be separated by a barrier layer. This can suppress the diffusion of hydrogen from transistor 300 to transistor 500.

[0110] In the above, a wiring layer containing a conductor 356, a wiring layer containing a conductor 366, and a conductor 376 Although the wiring layer including the conductive 386 has been described, this embodiment is not applicable. The semiconductor device is not limited to this. A wiring layer similar to a wiring layer containing conductor 356 The number of layers may be three or less, or the wiring layers similar to the wiring layer containing the conductor 356 may be made five or more layers. That's good too.

[0111] Insulator 384 has insulators 510, 512, 514, and 516. They are arranged in a stack in order. Insulator 510, insulator 512, insulator 514, and insulating It is preferable that one of the surrounding bodies 516 be made of a material that has barrier properties against oxygen and hydrogen. stomach.

[0112] For example, the insulator 510 and the insulator 514 have, for example, a substrate 311 or a transient From the area where transistor 300 is installed, hydrogen and impurities are present in the area where transistor 500 is installed. It is preferable to use a film that has barrier properties to prevent diffusion. Therefore, insulator 32 The same materials as in 4 can be used.

[0113] As an example of a film with hydrogen barrier properties, silicon nitride formed by CVD is used. This can be done. Here, a semiconductor device having an oxide semiconductor such as transistor 500, Hydrogen diffusion can degrade the properties of the semiconductor device. Therefore, A film that suppresses hydrogen diffusion is used between transistor 500 and transistor 300. This is preferable. Specifically, a membrane that suppresses hydrogen diffusion is a membrane that releases less hydrogen. .

[0114] Furthermore, as films having barrier properties against hydrogen, for example, insulator 510 and insulator 5 14 uses metal oxides such as aluminum oxide, hafnium oxide, and tantalum oxide. It is preferable.

[0115] In particular, aluminum oxide is a source of oxygen and hydrogen, which can cause variations in the electrical properties of transistors. It has a high barrier effect that prevents both water and other impurities from passing through the film. Aluminum oxide is susceptible to hydrogen, moisture, and other elements during and after the transistor fabrication process. This prevents impurities from entering transistor 500. This can suppress the release of oxygen from the oxides that make up the transistor. It is suitable for use as a protective film against 500.

[0116] Furthermore, for example, the same material as the insulator 320 is used for insulators 512 and 516. It is possible to do so by applying materials with relatively low dielectric constants to these insulators. This can reduce parasitic capacitance between wirings. For example, insulator 512 and insulation As body 516, silicon oxide films, silicon oxide nitride films, and the like can be used.

[0117] Furthermore, insulators 510, 512, 514, and 516 contain a conductor 5 18, and a conductor (e.g., conductor 503) that constitutes the transistor 500 is embedded. It is made. Note that conductor 518 is connected to capacitor 600 or transistor 300. It functions as a plug or wiring. Conductor 518 is connected to conductor 328, and is conductive It can be provided using the same material as body 330.

[0118] In particular, the conductor 518 in the region in contact with the insulator 510 and the insulator 514 is oxygen, hydrogen, And preferably it is a conductor that has barrier properties against water. With this configuration, Transistor 300 and Transistor 500 have barrier properties against oxygen, hydrogen, and water. In the layer, it can be separated, and hydrogen from transistor 300 to transistor 500 It can suppress diffusion.

[0119] A transistor 500 is provided above the insulator 516.

[0120] As shown in Figures 10A and 10B, transistor 500 is an insulator 514 and an insulating A conductor 503 is positioned to be embedded in the body 516, and the insulator 516 and conductor 5 An insulator 520 placed on top of 03, and an insulator 522 placed on top of insulator 520, An insulator 524 placed on top of insulator 522, and an oxide 5 placed on top of insulator 524 30a, oxide 530b placed on oxide 530a, and on oxide 530b, Conductors 542a and 542b are arranged separately from each other, and conductor 542a and conductor It is placed on the body 542b and is superimposed between the conductor 542a and the conductor 542b to form an opening. The insulator 580, oxide 530c and oxide 53 are arranged on the bottom and sides of the opening. An insulator 550 is placed on the formation surface of 0c, and a conductor 5 is placed on the formation surface of the insulator 550. It has 60 and

[0121] Furthermore, as shown in Figures 10A and 10B, oxide 530a, oxide 530b, conductor An insulator 544 is placed between 542a and the conductor 542b and the insulator 580. This is preferable. Also, as shown in Figures 10A and 10B, the conductor 560 is an insulator 5 A conductor 560a is provided inside 50, and is embedded inside the conductor 560a It is preferable to have a conductor 560b provided. Also, Figures 10A and 10B As shown, an insulator 574 is placed on top of an insulator 580, a conductor 560, and an insulator 550. It is preferable that they be arranged in this manner.

[0122] In this specification, oxides 530a, 530b, and 530c are used interchangeably. These are sometimes collectively referred to as oxide 530.

[0123] Furthermore, in transistor 500, oxidation occurs in the region where the channel is formed and in its vicinity. The following describes a configuration in which three layers of material 530a, oxide 530b, and oxide 530c are laminated. However, the present invention is not limited thereto. For example, a single layer of oxide 530b, oxidation Two-layer structure of substance 530b and oxide 530a, two-layer structure of oxide 530b and oxide 530c, Alternatively, a configuration with a stacked structure of four or more layers may be used. Furthermore, in transistor 500, Although the conductor 560 is shown as a two-layer laminated structure, the present invention is not limited thereto. For example, the conductor 560 may have a single-layer structure or a laminated structure of three or more layers. This is also acceptable. Furthermore, the transistor 500 shown in Figures 8 and 10A is just one example, and its structure is not limited to that. It is not necessary to use a specific transistor; instead, an appropriate transistor should be used depending on the circuit configuration and driving method.

[0124] Here, conductor 560 functions as the gate electrode of the transistor, and conductor 542a and The conductor 542b functions as either a source electrode or a drain electrode, respectively. In addition, the conductor 560 is connected to the opening of the insulator 580, and to the conductors 542a and 542b. It is formed so as to be embedded in the sandwiched region. Conductor 560, Conductor 542a and Conductor The arrangement of the electric element 542b is selected in a self-aligned manner with respect to the opening of the insulator 580. In transistor 500, the gate electrode is connected between the source electrode and the drain electrode, self It can be arranged in a consistent manner. Therefore, the conductor 560 is provided with a margin for alignment. Since it can be formed without any additional steps, the occupied area of ​​transistor 500 can be reduced. This makes it possible to miniaturize and highly integrate semiconductor devices.

[0125] Furthermore, the conductor 560 is formed in a self-aligned manner in the region between conductor 542a and conductor 542b. Therefore, the conductor 560 has a region that overlaps with conductor 542a or conductor 542b. It does not have. As a result, a shape is formed between the conductor 560 and the conductors 542a and 542b. The resulting parasitic capacitance can be reduced. Therefore, the switching of transistor 500 This allows for increased speed and improved frequency response.

[0126] Conductor 560 may function as the first gate (also called the top gate) electrode. Furthermore, the conductor 503 functions as a second gate (also called a bottom gate) electrode. There is a match. In that case, the potential applied to conductor 503 is the same as the potential applied to conductor 560, By changing it independently, without linking it to other functions, the threshold voltage of transistor 500 is controlled. This is possible. In particular, by applying a negative potential to the conductor 503, the transistor 50 By making the threshold voltage for 0 greater than 0V, it becomes possible to reduce the off-current. Therefore Therefore, applying a negative potential to the conductor 503 results in a greater effect on the conductor 560 than not applying a negative potential. The drain current can be reduced when the applied potential is 0V.

[0127] The conductor 503 is positioned to overlap with the oxide 530 and the conductor 560. Therefore, when a potential is applied to the conductor 560 and the conductor 503, the conductor 560 generates The electric field generated by the conductor 503 connects with the electric field generated by the conductor 503, forming a chain in the oxide 530. It can cover the flannel formation region.

[0128] In this specification, etc., a pair of gate electrodes (a first gate electrode and a second gate electrode) The electric field electrically surrounds the transistor structure that forms the channel formation region, This is called an ounded channel (S-channel) structure. Also, in this specification, etc. In this context, the surrounded channel (S-channel) structure is, Acid in contact with conductors 542a and 542b, which function as electrodes and drain electrodes. The sides and periphery of compound 530 have the characteristic of being type I, just like the channel-forming region. In addition, the sides and periphery of the oxide 530 in contact with the conductors 542a and 542b. Since the edges are in contact with the insulator 544, they can be I-shaped, similar to the channel-forming region. In this specification, Type I can be treated the same as high-purity intrinsic resin, as described later. Furthermore, the S-channel structures disclosed herein include Fin-type structures and Planar-type structures. The structure is different. By adopting an S-channel structure, resistance to short-channel effects is achieved. This improves performance, or in other words, it makes it possible to create a transistor that is less susceptible to short-channel effects.

[0129] Furthermore, the conductor 503 has the same configuration as the conductor 518, and the insulators 514 and 5 A conductor 503a is formed in contact with the inner wall of the 16 openings, and a conductor 503b is formed further inside. This has been done. Furthermore, in transistor 500, conductors 503a and 503b are used. Although the present invention describes a stacked configuration, it is not limited thereto. For example, The electrical body 503 may be configured as a single layer or a laminated structure of three or more layers.

[0130] Here, the conductor 503a allows for the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, and copper atoms. It is preferable to use a conductive material that has a suppressive function (i.e., the above-mentioned impurities are less likely to permeate it). i. Or, inhibit the diffusion of oxygen (for example, at least one such as an oxygen atom or oxygen molecule). It is preferable to use a conductive material that has a functional property (i.e., one that is impermeable to the above-mentioned oxygen). In this specification, the function of suppressing the diffusion of impurities or oxygen means the above-mentioned impurities or The function is to suppress the diffusion of any one or all of the above-mentioned oxygen species.

[0131] For example, conductor 503a has the function of suppressing oxygen diffusion, so conductor 503b This can suppress the oxidation that causes a decrease in conductivity.

[0132] Furthermore, if the conductor 503 also functions as wiring, the conductor 503b may be tungsten, copper, Alternatively, it is preferable to use a highly conductive material, mainly composed of aluminum. In this embodiment, the conductor 503 is shown as a laminate of conductor 503a and conductor 503b. However, the conductor 503 may have a single-layer structure.

[0133] Insulators 520, 522, and 524 function as a second gate insulating film. It holds.

[0134] Here, the insulator 524 in contact with the oxide 530 is more than the oxygen that satisfies the stoichiometric composition. It is preferable to use an insulator containing oxygen. In other words, the insulator 524 contains excess oxygen. It is preferable that such an insulator containing excess oxygen is brought into contact with oxide 530. By providing this, the oxygen deficiency (V) in oxide 530 is reduced. O :oxygen vacanc This reduces (also known as y) and improves the reliability of transistor 500. When hydrogen enters an oxygen vacancy in oxide 530, the defect (hereinafter referred to as V) O It is sometimes called H It) functions as a donor, and electrons that are carriers may be generated. Also, hydrogen may combine with oxygen that binds to metal atoms to generate electrons that are carriers . Therefore, a transistor using an oxide semiconductor containing a large amount of hydrogen tends to have normal-off characteristics. Also, hydrogen in the oxide semiconductor is likely to move due to stresses such as heat and an electric field. Thus, when a large amount of hydrogen is contained in the oxide semiconductor, the reliability of the transistor may deteriorate . In one aspect of the present invention, VH in the oxide 530 is reduced as much as possible and preferably made highly pure intrinsic or substantially highly pure intrinsic. Thus, in order to obtain an oxide semiconductor in which VH is O sufficiently reduced, it is important to remove impurities such as moisture and hydrogen in the oxide semiconductor (sometimes referred to as dehydration and dehydrogenation treatment), and to supply oxygen to the oxide semiconductor to compensate for oxygen deficiencies (sometimes referred to as oxygen addition treatment). By using an oxide semiconductor in which impurities such as VH are sufficiently reduced in the channel formation region of the transistor, stable electrical characteristics can be imparted O . As the insulator having an excess oxygen region, specifically, it is preferable to use an oxide material in which some oxygen is desorbed by heating. An oxide that desorbs oxygen by heating is one in which the desorption amount of oxygen in terms of oxygen atoms is 1.0×10 atoms / cm or more, preferably 1.0× 10 O atoms / cm or more, and more preferably 2.0×10

[0135] in TDS (Thermal Desorption Spectroscopy) analysis . calculated to 18 3 19 3 19 ​​​​​atoms / cm 3 Above, or 3.0 × 10 20 atoms / cm 3 The above describes the oxide film. The surface temperature of the film during the above TDS analysis is between 100°C and 700°C, or 10 A temperature range of 0°C to 400°C is preferred.

[0136] Furthermore, the insulator having the above excess oxygen region and oxide 530 are brought into contact and heat treated, microphone One or more of the following processes may be performed: low-wave processing or RF processing. By doing so, water or hydrogen can be removed from oxide 530. For example, oxide 5 At 30, a reaction occurs in which the VoH bond is broken, or in other words, "V O H→Vo+H The following reaction occurs, allowing for dehydrogenation. Some of the hydrogen produced at this time is acid It combines with an element to form H2O, and is removed from oxide 530 or the insulator near oxide 530. In some cases, this may occur. Also, some of the hydrogen may be gettered by the conductor 542.

[0137] Furthermore, the above microwave processing is performed using, for example, an apparatus having a power supply that generates high-density plasma. Alternatively, it is preferable to use a device that has a power supply that applies RF to the substrate side. For example, acid By using a gas containing elements and employing a high-density plasma, high-density oxygen radicals are generated. This can be achieved by applying RF to the substrate side, generating high-density plasma. Efficiently introduce oxygen radicals into oxide 530 or an insulator near oxide 530. This can be done. Furthermore, the above microwave treatment is performed at a pressure of 133 Pa or higher, preferably 200 Pa. The Pa should be Pa or higher, more preferably 400 Pa or higher. For example, oxygen and argon are used as gases introduced into the apparatus, with an oxygen flow rate ratio (O2 The process should be carried out with (O2+Ar) content of 50% or less, preferably between 10% and 30%.

[0138] Furthermore, during the manufacturing process of transistor 500, the surface of oxide 530 is exposed. Therefore, heat treatment is preferable. This heat treatment is, for example, between 100°C and 450°C. More preferably, the heating should be carried out at a temperature of 350°C to 400°C. The heat treatment is performed using nitrogen gas. Alternatively, an inert gas atmosphere, or an oxidizing gas at 10 ppm or more, 1% or more, The procedure should be carried out in an atmosphere containing 10% or more of the substance. For example, heat treatment is preferably carried out in an oxygen atmosphere. This supplies oxygen to oxide 530, thus eliminating oxygen deficiency (V O ) can be reduced. Furthermore, the heat treatment may be carried out under reduced pressure. Alternatively, the heat treatment may be carried out under nitrogen gas or After heat treatment in an active gas atmosphere, an oxidizing gas is added at 10 pJ to replenish the desorbed oxygen. The procedure may be carried out in an atmosphere containing 1% or more of the substance, or 10% or more of the substance. Alternatively, an oxidizing gas may be used. After heat treatment in an atmosphere containing 10 ppm or more, 1% or more, or 10% or more, then continuously The heat treatment may be carried out in a nitrogen gas or inert gas atmosphere.

[0139] Furthermore, by performing an oxygenation treatment on oxide 530, the oxygen deficiencies in oxide 530 are supplied. The oxygen used for repair, or in other words, the reaction "Vo + O → null" is promoted. Furthermore, the oxygen supplied reacts with the hydrogen remaining in oxide 530. This allows the hydrogen to be removed as H2O (dehydrated). This eliminates oxidation. The hydrogen remaining in substance 530 recombines with the oxygen vacancy and V OSuppress the formation of H This is possible.

[0140] Also, when the insulator 524 has an excess oxygen region, the insulator 522 preferably has a function of suppressing the diffusion of oxygen (e.g., oxygen atoms, oxygen molecules, etc.) (the above oxygen is difficult to permeate). This is preferable. This is preferable.

[0141] By the insulator 522 having a function of suppressing the diffusion of oxygen and impurities, the oxygen possessed by the oxide 530 does not diffuse to the insulator 520 side, which is preferable. Also, the conductor 503 can be suppressed from reacting with the oxygen possessed by the insulator 524 and the oxide 530. This is preferable. Also, the conductor 503 can be suppressed from reacting with the oxygen possessed by the insulator 524 and the oxide 530. This is possible.

[0142] The insulator 522 is preferably a single layer or a laminate of an insulator containing a so-called high-k material such as aluminum oxide, hafnium oxide, an oxide containing aluminum and hafnium (hafnium aluminate), tantalum oxide, zirconium oxide, lead zirconate titanate (PZT), strontium titanate (SrTiO3), or (Ba,Sr)TiO3 (BST). As the miniaturization and high integration of transistors progress, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it becomes possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. This is preferable. As the miniaturization and high integration of transistors progress, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it becomes possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. This is preferable. As the miniaturization and high integration of transistors progress, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it becomes possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. This is preferable. As the miniaturization and high integration of transistors progress, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it becomes possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. This is preferable. As the miniaturization and high integration of transistors progress, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it becomes possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. This is preferable. As the miniaturization and high integration of transistors progress, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it becomes possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. This is preferable. As the miniaturization and high integration of transistors progress, problems such as leakage current may occur due to the thinning of the gate insulating film. By using a high-k material for the insulator that functions as the gate insulating film, it becomes possible to reduce the gate potential during transistor operation while maintaining the physical film thickness. This is possible.

[0143] In particular, it is advisable to use an insulator containing one or both oxides of aluminum and hafnium, which is an insulating material having a function of suppressing the diffusion of impurities and oxygen (the above oxygen is difficult to permeate). This is preferable. This is preferable. , aluminum oxide, hafnium oxide, aluminum and hafnium oxide ( It is preferable to use materials such as humic aluminate. When 22 is formed, the insulator 522 prevents the release of oxygen from the oxide 530 and the transistor It functions as a layer that suppresses the incorporation of impurities such as hydrogen from the peripheral area of ​​500 into the oxide 530. .

[0144] Alternatively, these insulators may contain, for example, aluminum oxide, bismuth oxide, or germanium oxide. M, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, acid Zirconium oxide may be added. Alternatively, these insulators may be nitrided. Silicon oxide, silicon oxide-nitride, or silicon nitride may be used as an insulator in a laminated form.

[0145] Furthermore, it is preferable that the insulator 520 is thermally stable. For example, silicon oxide and Silicon oxide nitride is suitable because it is thermally stable. Also, high-k material By combining the insulator with silicon oxide or silicon oxide nitride, thermal stability and A laminated insulator 520 with a high dielectric constant can be obtained.

[0146] The transistor 500 is formed in the oxide 530 including the channel formation region as an oxide semiconductor. It is preferable to use a metal oxide that can perform the function. For example, as oxide 530, In-MZ n oxide (element M is aluminum, gallium, yttrium, copper, vanadium, beryllium) Um, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, rancid Tan, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium It is preferable to use one or more metal oxides selected from the above. In particular, oxide 5 In-M-Zn oxides that can be applied as 30 are CAAC-OS(c-axis ali (gned crystalline oxide semiconductor) This is preferable. Alternatively, CAC-OS (Cloud-Aligned Compositing) It is preferable that it is a te oxide semiconductor. C represents an example of a crystal structure, and CAC represents an example of a function or material composition. Also, oxidation In-Ga oxide and In-Zn oxide may be used as material 530.

[0147] CAC-OS refers to a material that possesses both conductive and insulating properties in some parts. It possesses the properties of a semiconductor as a whole. Note that CAC-OS or CAC-m When ethanol oxide is used in the active layer of a transistor, its conductive function is due to the carrier The function of A is to allow electrons (or holes) to flow, and the insulating function is to allow carrier electrons to flow. It has a function to prevent flow. It utilizes the complementary functions of conductivity and insulation. This allows the switching function (the function to turn on / off) to be controlled by CAC-OS or CAC -Can be applied to metal oxide. CAC-OS or CAC-meta In 1-oxide, by separating the functions of each component, the functions of both components can be maximized. It is possible to do so.

[0148] Furthermore, CAC-OS or CAC-metal oxide has conductive and insulating properties. It has regions. The conductive region has the conductive function described above, and the insulating region has the insulating function described above. It has the function of [this]. Furthermore, within the material, the conductive region and the insulating region are at the nanoparticle level. In some cases, they are separated by a rib. Also, conductive regions and insulating regions are located within the material. They may be unevenly distributed. Furthermore, the conductive regions appear blurred around the edges and connected in a cloud-like pattern. There are cases where this occurs.

[0149] Furthermore, in CAC-OS or CAC-metal oxide, the conductive region and the insulating region The marginal region is defined as being between 0.5 nm and 10 nm, preferably between 0.5 nm and 3 nm. These particles may be dispersed in the material at the following sizes.

[0150] Furthermore, CAC-OS or CAC-metal oxide have different band gaps. It is composed of the following components. For example, CAC-OS or CAC-metal oxid e consists of a component with a wide gap due to the insulating region and a narrow gap due to the conductive region. - It consists of a component having a gap. In this configuration, when the carrier is flowed, In components with a narrow gap, mainly carriers flow. Also, the narrow gap The components possessed act complementaryly with components having a wide gap, and have a narrow gap. Carriers also flow to components with a wide gap in conjunction with the components. Therefore, the above CA C-OS or CAC-metal oxide is used in the channel formation region of the transistor. In this case, the transistor has a high current driving force in the ON state, that is, a large ON current, and High field-effect mobility can be obtained.

[0151] In other words, CAC-OS or CAC-metal oxide is a matrix composite material. (matrix composite), or metal matrix composite (metal m It can also be called an atrix composite.

[0152] Furthermore, metal oxides that function as oxide semiconductors include single-crystal oxide semiconductors and other non-metal oxides. They can be divided into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. C-OS, polycrystalline oxide semiconductor, nc-OS (nanocrystalline oxide de semiconductor), pseudo-amorphous oxide semiconductor (a-like OS: (non-linear-like oxide semiconductor), and non Examples include crystalline oxide semiconductors.

[0153] IGZO can be broadly divided into Amorphous and Crystalline. They are classified into crystalline and crystallized. Also, within Amorphous... This includes completely amorphous. Also, Crystal Among the ine molecules, there is CAAC (c-axis aligned crystalline). nc (nanocrystalline), and CAC (Cloud-Aligned This includes Composite. Note that the classification of Crystalline includes sin Gle crystal, poly crystal, and completely am Orphous is excluded. Also, among Crystals, there is single crystal. This includes aluminum and polycrystalline materials.

[0154] CAAC-OS has c-axis orientation and multiple nanocrystals are linked in the ab-plane direction. Furthermore, it has a distorted crystal structure. Note that distortion refers to the region where multiple nanocrystals are connected. Within the region, between a region with aligned lattice arrangements and another region with aligned lattice arrangements, This refers to the part where the direction has changed.

[0155] Nanocrystals are based on a hexagonal structure, but they are not necessarily regular hexagons; they can also be non-regular hexagonal. Yes, it exists. Furthermore, the distortion may have lattice arrangements such as pentagons and heptagons. Furthermore, in CAAC-OS, even near strain, clear grain boundaries (grain bounds) are present. It is difficult to confirm (also called Dally). In other words, due to the distortion of the lattice arrangement, the crystal It can be seen that grain boundary formation is suppressed. This is because CAAC-OS is in the ab-plane direction. In this case, the arrangement of oxygen atoms is not dense, and the substitution of metal elements reduces the interatomic bond distance. This is because the distortion can be tolerated due to changes in other factors.

[0156] Furthermore, CAAC-OS consists of a layer containing indium and oxygen (hereinafter referred to as the In layer), and elements A layered crystalline structure in which layers containing M, zinc, and oxygen (hereinafter referred to as (M,Zn) layers) are stacked. It tends to have a layered structure (also called a structure). Furthermore, indium and element M are substituted for each other. It is possible, and if element M in the (M,Zn) layer is replaced with indium, then (In,M,Zn) It can also be represented as a layer. Furthermore, if the indium in the In layer is substituted with element M, then (In,M It can also be represented as a layer.

[0157] CAAC-OS is a highly crystalline metal oxide. On the other hand, CAAC-OS has a distinct crystal structure. Because it is difficult to identify grain boundaries, a decrease in electron mobility caused by grain boundaries is less likely to occur. It can be said that the crystallinity of metal oxides decreases due to the inclusion of impurities and the formation of defects. Because this can happen, CAAC-OS is a metal oxide with few impurities or defects (such as oxygen deficiencies). It can also be said that metal oxides containing CAAC-OS have stable physical properties. Therefore, metal oxides containing CAAC-OS are heat-resistant and highly reliable.

[0158] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially between 1 nm and 3 nm). It has periodicity in the atomic arrangement in the region of less than nm. Furthermore, nc-OS has different nanometers. No regularity in crystal orientation is observed between crystals. Therefore, no orientation is observed throughout the entire film. Therefore, depending on the analysis method, nc-OS can be classified as a-like OS or amorphous oxide semiconductor. It can sometimes be difficult to distinguish between them.

[0159] In addition, In-G is a type of metal oxide containing indium, gallium, and zinc. α-Zn oxide (also called "IGZO") has a stable structure when formed into the nanocrystals described above. In some cases, this may be the case. In particular, IGZO tends to have difficulty growing crystals in the atmosphere, so Smaller crystals than large crystals (here, crystals of several millimeters or several centimeters) (for example, Using the aforementioned nanocrystal structure may result in greater structural stability.

[0160] a-like OS is a metal oxide having a structure between nc-OS and amorphous oxide semiconductors. It is a substance. an a-like OS has porous or low-density regions. That is, a-lik e OS has lower crystallinity compared to nc-OS and CAAC-OS.

[0161] Oxide semiconductors (metal oxides) can take on diverse structures, each possessing different properties. One embodiment of the invention is an oxide semiconductor, an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, and an a-lik It may have two or more of the following: e OS, nc-OS, and CAAC-OS.

[0162] Furthermore, it is preferable to use a metal oxide with a low carrier concentration for transistor 500. When reducing the carrier concentration of the metal oxide, the impurity concentration in the metal oxide is reduced. Therefore, it is sufficient to lower the defect level density. In this specification, the impurity concentration is low and the defect level A low ion density is referred to as high-purity intrinsic or substantially high-purity intrinsic. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, and nickel. , silicone, etc.

[0163] In particular, the hydrogen contained in metal oxides reacts with the oxygen bonded to the metal atoms to form water, Oxygen vacancies can form in metal oxides. If defects are present, the transistor may exhibit normally-on characteristics. Furthermore, A defect where hydrogen fills an oxygen vacancy functions as a donor, generating electrons, which act as carriers. Furthermore, some of the hydrogen combines with the metal atom, and oxygen combines with the electron carrier. This can generate transients. Therefore, transients using metal oxides that contain a lot of hydrogen are produced. Ta tends to exhibit normally-on characteristics.

[0164] Defects where hydrogen fills an oxygen vacancy can function as donors for metal oxides. However, It is difficult to quantitatively evaluate the defect in question. Therefore, in metal oxides, donor In some cases, evaluation is based on carrier concentration rather than concentration. Therefore, in this specification, etc., metal acids The parameters of the compound are not the donor concentration, but rather the assumption that no electric field is applied. Rear concentration may be used. In other words, the "carrier concentration" described in this specification, etc., is "Dona It can sometimes be rephrased as "concentration."

[0165] Therefore, when using metal oxides in oxide 530, the amount of hydrogen in the metal oxide should be reduced as much as possible. It is preferable that this is done. Specifically, in metal oxides, secondary ion mass spectrometry ( SIMS (Secondary Ion Mass Spectrometry) The hydrogen concentration obtained is 1 × 10 20 atoms / cm 3 Less than 1 × 10 19 a toms / cm 3 Less than 5x10 18 atoms / cm 3 Less than, even better Mashiku is 1 x 10 18 atoms / cm 3 It shall be less than. Impurities such as hydrogen shall be sufficiently reduced. By using a metal oxide in the channel formation region of a transistor, stable electrical characteristics can be achieved. It can be granted.

[0166] Furthermore, when a metal oxide is used for oxide 530, the metal oxide carrier in the channel formation region The concentration is 1 × 10 18 cm -3 The following is preferable: 1 × 10 17 cm -3 less than It is more preferable that it be 1 × 10 16 cm -3 It is even more preferable that it be less than 1 ×10 13 cm -3 It is even more preferable that it be less than 1 × 10 12 cm -3 Less than It is even more preferable that the lower limit of the carrier concentration of the metal oxide in the channel formation region is Therefore, there are no particular limitations, but for example, 1 x 10 -9 cm -3 It can be done this way.

[0167] Furthermore, when a metal oxide is used for oxide 530, the conductor 542 (conductor 542a, and When the conductor 542b) and the oxide 530 come into contact, the oxygen in the oxide 530 enters the conductor 54 It may diffuse into 2, causing the conductor 542 to oxidize. When the conductor 542 oxidizes, the conductivity There is a high probability that the conductivity of body 542 will decrease. Note that oxygen in oxide 530 is present in conductor 542. To describe the diffusion into the oxide 530, it can be rephrased as the conductor 542 absorbing oxygen from the oxide 530. It is possible.

[0168] Furthermore, the oxygen in oxide 530 is conductor 542 (conductor 542a and conductor 542b) By diffusion, the conductor 542a and oxide 530b, and the conductor 542b and A different layer may be formed between the oxide 530b and the conductor 542. Because it contains a large amount of oxygen, this different layer is presumed to have insulating properties. At this time, conductor 542 The three-layer structure of the aforementioned heterogeneous layer and oxide 530b is a three-layer structure consisting of metal-insulator-semiconductor. It can be considered a structure, and MIS (Metal-Insulator-Semiconductor) It is sometimes called a ctor structure, or a diode junction structure that mainly consists of MIS structures. ru.

[0169] Furthermore, the above-mentioned heterogeneous layer is not limited to being formed between the conductor 542 and the oxide 530b. For example, when a different layer is formed between the conductor 542 and the oxide 530c, or when the conductor 54 The fields formed between 2 and oxide 530b, and between conductor 542 and oxide 530c There is a match.

[0170] Furthermore, the metal oxide that functions as a channel-forming region in oxide 530 is bandg It is preferable to use a cap with a voltage of 2 eV or more, preferably 2.5 eV or more. By using metal oxides with a large band gap, the off-current of the transistor can be reduced. It can be reduced.

[0171] Oxide 530 has oxide 530a beneath oxide 530b, so oxide 530a Furthermore, it is possible to suppress the diffusion of impurities from the structure formed below to oxide 530b. It can be done. Also, by having oxide 530c on oxide 530b, oxide 530c is better than The diffusion of impurities from the structure formed above to oxide 530b can be suppressed. .

[0172] Furthermore, oxide 530 has a layered structure of multiple oxide layers with different atomic ratios of each metal atom. It is preferable that the metal oxide used in oxide 530a contains constituent elements The atomic ratio of element M in the oxide is the element of the constituent elements in the metal oxide used in oxide 530b. It is preferable that the ratio is greater than the atomic ratio of element M. Also, the metal oxide used in oxide 530a In this case, the atomic ratio of element M to In is in the metal oxide used in oxide 530b. Furthermore, it is preferable that the atomic ratio of element M to In is greater than that of In. Also, in oxide 530b In the metal oxide used, the atomic ratio of In to element M is used in oxide 530a. It is preferable that the atomic ratio of In to element M in the metal oxide is greater than that of In. Oxide 530c is a metal oxide that can be used in oxide 530a or oxide 530b. The object can be used.

[0173] Furthermore, the energy at the lower end of the conduction band of oxide 530a and oxide 530c is It is preferable that the energy of b is higher than the energy of the lower end of the conduction band. In other words, oxide The electron affinity of 530a and oxide 530c is smaller than the electron affinity of oxide 530b. It is preferable.

[0174] Here, at the joint of oxide 530a, oxide 530b, and oxide 530c, The energy levels at the lower end of the guide band change smoothly. In other words, oxide 530a, oxide The energy levels at the lower end of the conduction band at the junction of 530b and oxide 530c are continuous. It can also be said that it undergoes a gradual change or continuous bonding. In order to do this, oxide 5 At the interface between 30a and oxide 530b, and at the interface between oxide 530b and oxide 530c It is desirable to lower the defect level density of the mixed layer that is formed.

[0175] Specifically, oxide 530a and oxide 530b, and oxide 530b and oxide 530c, By having a common element other than the primary element (as the main component), a mixed layer with a low defect level density is formed. It is possible. For example, if oxide 530b is In-Ga-Zn oxide, then oxide 5 As 30a and oxide 530c, In-Ga-Zn oxide, Ga-Zn oxide, oxide Gallium or similar materials would be suitable.

[0176] In this case, the main carrier pathway is oxide 530b. Oxide 530a, oxide 53 By configuring 0c as described above, the interface between oxide 530a and oxide 530b, and oxidation The defect level density at the interface between material 530b and oxide 530c can be reduced. Therefore, the influence of interfacial scattering on carrier conduction is reduced, and transistor 500 has high On-current can be obtained.

[0177] On the oxide 530b are conductors 542a, which function as source and drain electrodes. , and a conductor 542b are provided. Conductors 542a and 542b are Aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium Um, beryllium, indium, ruthenium, iridium, strontium, lanthanum? A selected metal element, or an alloy containing the above-mentioned metal elements, or the above-mentioned metal elements It is preferable to use a combination of alloys, etc. For example, tantalum nitride, titanium nitride, tan Gusten, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, Ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum It is preferable to use oxides containing nickel. Also, tantalum nitride and titanium nitride are preferable. , nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, lutein oxide nium, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel Oxides containing ions are conductive materials that are resistant to oxidation, or maintain their conductivity even when absorbing oxygen. It is preferable because it is a material that can withstand hydrogen or acid. Furthermore, metal nitride films such as tantalum nitride can withstand hydrogen or acid. It is preferable because it has barrier properties against the element.

[0178] Furthermore, although conductors 542a and 542b are shown as single-layer structures in Figure 10, A laminated structure of two or more layers is also possible. For example, a tantalum nitride film and a tungsten film may be laminated. This is good. Alternatively, a titanium film and an aluminum film may be laminated. Also, on a tungsten film A two-layer structure with stacked aluminum films, and a copper film on top of a copper-magnesium-aluminum alloy film. Laminated two-layer structure, two-layer structure with copper film laminated on titanium film, copper film laminated on tungsten film It may also be a two-layered structure.

[0179] Furthermore, a titanium film or titanium nitride film, and an aluminum film layered on top of the titanium film or titanium nitride film. A titanium film or copper film is laminated, and then a titanium film or titanium nitride film is formed on top of it. Three-layer structure, molybdenum film or molybdenum nitride film, and the molybdenum film or molybdenum nitride An aluminum film or copper film is laminated on top of the molybdenum film, and then a molybdenum film is placed on top of that. It has a three-layer structure that forms a molybdenum nitride film, etc. Furthermore, indium oxide, tin oxide or A transparent conductive material containing zinc oxide may also be used.

[0180] Furthermore, as shown in Figure 10A, the oxide 530 and the conductor 542a (conductor 542b) Regions 543a and 543b are formed at and near the interface as low-resistance regions. In some cases, region 543a may function as either the source region or the drain region. Region 543b can function as either the source region or the drain region. A channel-forming region is formed in the area sandwiched between region 543a and region 543b.

[0181] By providing the conductor 542a (conductor 542b) in contact with the oxide 530, The oxygen concentration in region 543a (region 543b) may decrease. Also, region 543a (region In region 543b), the metal contained in conductor 542a (conductor 542b) and the oxide 530 A metal compound layer containing the component may be formed. In such cases, region 543a (region The carrier density in region 543b increases, and region 543a (region 543b) becomes a low-resistance region. ru.

[0182] The insulator 544 is provided so as to cover the conductors 542a and 542b, and the conductor The oxidation of 542a and conductor 542b is suppressed. At this time, the insulator 544 is oxide It may be provided to cover the side of 530 and to be in contact with the insulator 524.

[0183] Insulator 544 includes hafnium, aluminum, gallium, yttrium, and zirconium. Tungsten, titanium, tantalum, nickel, germanium, neodymium, lanthanum Alternatively, a metal oxide containing one or more metals selected from magnesium, etc., may be used. It is possible to use silicon nitride or silicon nitride as the insulator 544. It can also be used.

[0184] In particular, as insulator 544, an oxide of either aluminum or hafnium, or both. Insulators containing aluminum oxide, hafnium oxide, aluminum, and hafnium It is preferable to use an oxide containing um (hafnium aluminate), etc. In particular, haf Aluminium aluminate has higher heat resistance than hafnium oxide film. Therefore, in subsequent processes... In heat treatment, it is preferable because it does not easily crystallize. Note that conductor 542a and conductor 542b is a material that is oxidation-resistant, or whose conductivity does not significantly decrease even when it absorbs oxygen. In this case, insulator 544 is not an essential component. The design should be appropriate depending on the desired transistor characteristics. That's all you need to do.

[0185] The presence of the insulator 544 allows water and other impurities such as hydrogen contained in the insulator 580 to be acidic. The diffusion of oxide 530c to oxide 530b via insulator 550 is suppressed. Yes, it is possible. Furthermore, the excess oxygen in the insulator 580 suppresses the oxidation of the conductor 560. It is possible.

[0186] Insulator 550 functions as the first gate insulating film. Insulator 550 is oxide 530c It is preferable to place it in contact with the inside (top surface and side surface) of the insulator 550 as described above. Similar to insulator 524, an insulator that contains an excess of oxygen and releases oxygen upon heating It is preferable to use this method to form the product.

[0187] Specifically, silicon oxide, silicon oxide nitride, silicon nitride oxide, and silicon oxide containing excess oxygen. Silicon oxide, silicon oxide with added fluorine, silicon oxide with added carbon, carbon, and Silicon oxide with added nitrogen and silicon oxide with voids can be used. Silicon oxide and silicon oxide-nitride are preferred because they are stable to heat.

[0188] An insulator that releases oxygen upon heating is designated as insulator 550 and is brought into contact with the upper surface of oxide 530c. By providing this, the oxide 530b is transmitted from the insulator 550 through the oxide 530c. It can effectively supply oxygen to the channel-forming region. Also, similar to insulator 524. Preferably, the concentration of impurities such as water or hydrogen in the insulator 550 is reduced. The thickness of the edge body 550 is preferably between 1 nm and 20 nm.

[0189] Furthermore, in order to efficiently supply excess oxygen from the insulator 550 to the oxide 530, A metal oxide may be provided between the body 550 and the conductor 560. The metal oxide is an insulator. It is preferable to suppress oxygen diffusion from 550 to the conductor 560. By providing a metal oxide, the diffusion of excess oxygen from the insulator 550 to the conductor 560 is suppressed. This means that the decrease in the amount of excess oxygen supplied to oxide 530 can be suppressed. This can suppress the oxidation of the conductor 560 due to excess oxygen. The metal oxide in question is Any material suitable for use as an insulator 544 may be used.

[0190] Furthermore, the insulator 550 may have a multilayer structure, similar to the second gate insulating film. As the miniaturization and integration of the grid progresses, the thinning of the gate insulating film leads to leakage current, etc. Because problems may occur, the insulator that functions as the gate insulating film is made of high-k material. By creating a laminated structure of a material and a thermally stable material, the physical film thickness is maintained while preventing traction. This allows for a reduction in gate potential during inverter operation. Furthermore, it offers thermal stability and a high dielectric constant. It can be made into a layered structure.

[0191] The conductor 560, which functions as the first gate electrode, has a two-layer structure in Figures 10A and 10B. Although it is shown as such, it may be a single-layer structure or a laminated structure of three or more layers.

[0192] Conductor 560a contains hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and nitrogen oxide molecules. Conductive properties that suppress the diffusion of impurities such as N2O, NO, NO2, and copper atoms. It is preferable to use a material. Alternatively, oxygen (for example, oxygen atoms, oxygen molecules, etc.) It is preferable to use a conductive material that has the function of suppressing the diffusion of (1). Conductor 56 Because 0a has the function of suppressing oxygen diffusion, the oxygen contained in the insulator 550 This can suppress the oxidation of the conductor 560b and the resulting decrease in conductivity. Oxygen diffusion Examples of conductive materials that have the function of suppressing this include tantalum, tantalum nitride, and ruthenium. It is preferable to use um or ruthenium oxide. Also, as conductor 560a In that case, an oxide semiconductor applicable to oxide 530 can be used. By depositing 0b using the sputtering method, the electrical resistance of the conductor 560a is reduced. It can be made into an electrostatic material. This is called an OC (Oxide Conductor) electrode. It is possible.

[0193] Furthermore, the conductive material 560b is a conductive material whose main components are tungsten, copper, or aluminum. It is preferable to use the material. Also, since the conductor 560b also functions as wiring, It is preferable to use a highly conductive material. For example, tungsten, copper, or aluminum. A conductive material with um as its main component can be used. In addition, the conductor 560b has a laminated structure. It may also be used as a laminated structure of titanium or titanium nitride and the above conductive material. good.

[0194] The insulator 580 is provided on the conductors 542a and 542b via the insulator 544. It is possible. The insulator 580 preferably has an excess oxygen region. For example, insulator 58 As 0, silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, fluorine Silicon oxide with added carbon, silicon oxide with added carbon, carbon, and nitrogen-added acid It is preferable to have silicon dioxide, porous silicon oxide, or a resin. Silicon oxide and silicon oxide-nitride are preferred because they are thermally stable. In particular, acid Silicon oxide and porous silicon oxide readily form excess oxygen regions in subsequent processes. This is preferable because it allows for this.

[0195] The insulator 580 preferably has an excess oxygen region. By providing the edge 580 in contact with the oxide 530c, the oxygen in the insulator 580 is removed from the oxide. It can be efficiently supplied to oxide 530 through 530c. Note that insulator 58 It is preferable that the concentration of impurities such as water or hydrogen in the solution is reduced.

[0196] The opening in the insulator 580 is formed superimposed on the region between the conductor 542a and the conductor 542b. As a result, the conductor 560 has an opening in the insulator 580, and the conductor 542a and the conductor It is formed in a way that it is embedded in the region sandwiched between 542b.

[0197] When miniaturizing semiconductor devices, it is necessary to shorten the gate length, but the conductor 56 It is necessary to prevent the conductivity of 0 from decreasing. To achieve this, the film thickness of conductor 560 is increased. As a result, the conductor 560 may have a shape with a high aspect ratio. In this embodiment, the conductor Since 560 is to be embedded in the opening of the insulator 580, the conductor 560 has an aspect ratio Even with a highly shaped form, the conductive material 560 can be formed without collapsing during the process. ru.

[0198] The insulator 574 is located on the upper surface of the insulator 580, the upper surface of the conductor 560, and the upper surface of the insulator 550. It is preferable that it be provided in contact with the insulator 574. This allows for the creation of excess oxygen regions in the insulator 550 and the insulator 580. Therefore, oxygen can be supplied to the oxide 530 from the excess oxygen region.

[0199] For example, as insulator 574, hafnium, aluminum, gallium, yttrium, and Titanium, tungsten, titanium, tantalum, nickel, germanium, or magnesium Metal oxides containing one or more selected metals, such as cium, can be used. ru.

[0200] In particular, aluminum oxide has high barrier properties, and in thin films of 0.5 nm to 3.0 nm... However, the diffusion of hydrogen and nitrogen can be suppressed. Therefore, the sputtering method The aluminum oxide film formed using this method serves as both an oxygen source and a barrier against impurities such as hydrogen. It can also function as a membrane.

[0201] Furthermore, it is preferable to provide an insulator 581 that functions as an interlayer film on top of the insulator 574. Insulator 581, like insulator 524, has an impurity concentration of water or hydrogen in the film. It is preferable that it be reduced.

[0202] Furthermore, openings formed in insulators 581, 574, 580, and 544 Conductors 540a and 540b are placed in the opening. Conductors 540a and conductors 540b is provided opposite the conductor 560, with the conductor 540a and conductor 540. b has the same configuration as conductors 546 and 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, it is preferable to use a barrier material. The same material as body 514 can be used. For example, insulator 582 can be made of aluminum oxide. It is preferable to use metal oxides such as um, hafnium oxide, and tantalum oxide.

[0204] In particular, aluminum oxide is a source of oxygen and hydrogen, which can cause variations in the electrical properties of transistors. It has a high barrier effect that prevents both water and other impurities from passing through the film. Aluminum oxide is susceptible to hydrogen, moisture, and other elements during and after the transistor fabrication process. This prevents impurities from entering transistor 500. This can suppress the release of oxygen from the oxides that make up the transistor. It is suitable for use as a protective film against 500.

[0205] Furthermore, an insulator 586 is provided on the insulator 582. The insulator 586 is insulator 3 Similar materials to those used in 20 can be used. Furthermore, these insulators have a relatively low dielectric constant. By applying certain materials, parasitic capacitance between wires can be reduced. For example, insulation As component 586, silicon oxide films or silicon oxide-nitride films can be used.

[0206] Also, insulator 520, insulator 522, insulator 524, insulator 544, insulator 580, insulation Body 574, insulator 581, insulator 582, and insulator 586 are connected to conductor 546, and Conductors such as 548 are embedded within.

[0207] Conductors 546 and 548 are capacitors 600, transistors 500, or transistors. It functions as a plug or wiring to connect to the ZISTA 300. Conductor 546, and The conductor 548 is provided using the same material as the conductors 328 and 330. It is possible.

[0208] Furthermore, after the formation of the transistor 500, an opening is formed to surround the transistor 500. An insulator with high barrier properties against hydrogen or water may be formed to cover the opening. By encasing the transistor 500 in the aforementioned high-barrier insulator, moisture and other elements are prevented from entering from the outside. This can prevent hydrogen from entering. Alternatively, multiple transistors 500 can be used. Furthermore, it may be wrapped in an insulator with high barrier properties against hydrogen or water. When forming an opening to surround the inverter 500, for example, insulator 522 or insulator 5 The above-mentioned burr forms an opening that reaches 14 and contacts the insulator 522 or insulator 514. By forming a highly insulating material, it can also serve as part of the manufacturing process for transistor 500. , is preferable. Furthermore, an insulator with high barrier properties against hydrogen or water is, for example, The same material as insulator 522 or insulator 514 may be used.

[0209] Next, above transistor 500, capacitor 600 is provided. Capacitor 600 is, It has a conductor 610, a conductor 620, and an insulator 630.

[0210] Furthermore, a conductor 612 may be provided on the conductor 546 and the conductor 548. Conductor 6 12 functions as a plug or wire connecting to transistor 500. Conductive Body 610 functions as an electrode with a capacitance of 600. Note that conductor 612 and conductive Body 610 can be formed simultaneously.

[0211] Conductors 612 and 610 contain molybdenum, titanium, tantalum, and tungsten. A metal film containing elements selected from aluminum, copper, chromium, neodymium, and scandium. Alternatively, metal nitride films containing the above-mentioned elements (tantalum nitride film, titanium nitride film, monoxide nitride film) A ribdenum film, tungsten nitride film, etc., can be used. Alternatively, indium tin oxide can be used. Indium oxide containing tungsten oxide, indium zinc containing tungsten oxide Oxides, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, Conductive materials such as indium zinc oxide and indium tin oxide with added silicon oxide are applied. It is also possible.

[0212] In this embodiment, the conductor 612 and the conductor 610 are shown as a single-layer structure, but the configuration It is not limited to this, and may also be a laminated structure of two or more layers. For example, a conductor with barrier properties and a conductive A conductor with barrier properties between it and a highly conductive conductor, and a conductor that is tightly packed against a highly conductive conductor. A conductive material with high adhesion properties may be formed.

[0213] A conductor 620 is provided so as to overlap with the conductor 610 via an insulator 630. The conductor 620 uses a conductive material such as a metallic material, an alloy material, or a metal oxide material. This is possible. High-melting-point materials such as tungsten and molybdenum that offer both heat resistance and conductivity. It is preferable to use a conductive material, and it is particularly preferable to use tungsten. When forming it simultaneously with other structures, low-resistance metallic materials such as Cu (copper) or Al (aluminium) are used. You can use (Mu), etc.

[0214] An insulator 640 is provided on the conductor 620 and the insulator 630. 0 can be provided using the same material as insulator 320. Also, insulator 640 is It may also function as a flattening film that covers the uneven surface below it.

[0215] By using this structure, in semiconductor devices using transistors having oxide semiconductors This allows for miniaturization or high integration.

[0216] Substrates that can be used in a semiconductor device according to one aspect of the present invention include glass substrates and quartz substrates. , sapphire substrate, ceramic substrate, metal substrate (e.g., stainless steel substrate, ste Substrates having stainless steel foil, tungsten substrates, and tungsten foil (Surfaces such as), semiconductor substrates (for example, single-crystal semiconductor substrates, polycrystalline semiconductor substrates, or compound SOI (Silicon on Insulator) substrates (such as semiconductor substrates) , etc. can be used. Furthermore, it has heat resistance that can withstand the processing temperature of this embodiment. A plastic substrate may also be used. An example of a glass substrate is barium borosilicate glass. Sodium, aluminosilicate glass, or aluminoborosilicate glass, or soda lime Glass is one example. Other materials, such as crystallized glass, can also be used.

[0217] Alternatively, the substrate may be a flexible substrate, a laminated film, paper containing fibrous material, or A base film can be used. Flexible substrate, laminated film, base film Examples of materials like polyethylene terephthalate include the following: (PET), polyethylene naphthalate (PEN), polyethersulfone (PES) There are plastics, such as polytetrafluoroethylene (PTFE). Or, One example is synthetic resins such as acrylic. Another example is polypropylene. Examples include polyester, polyvinyl fluoride, or polyvinyl chloride. Examples include polyamide, polyimide, aramid, epoxy, inorganic vapor-deposited film, or paper. There are various types, etc. In particular, transients using semiconductor substrates, single crystal substrates, or SOI substrates. By manufacturing staves, variations in characteristics, size, or shape are minimized, and current High-performance, small-sized transistors can be manufactured. Using staves to construct a circuit can lead to lower power consumption or higher circuit integration. It is possible.

[0218] Furthermore, a flexible substrate is used as the substrate, and transistors, resistors, and A capacitor or other capacitance may be formed. Alternatively, a substrate, a transistor, a resistor, and / or Alternatively, a release layer may be provided between the capacitors, etc. The release layer is provided on top of a semiconductor device. After all the components are completed, they can be separated from the circuit board and used to transfer them to another circuit board. In that case, transistors, resistors, and / or capacitors are placed on substrates with poor heat resistance or flexible substrates. It can also be mounted on a substrate. The aforementioned release layer may, for example, consist of a tungsten film and silicon oxide. The configuration of a laminated structure of an inorganic film and a substrate, or a configuration in which an organic resin film such as polyimide is formed on a substrate. A silicon film containing hydrogen can be used.

[0219] In other words, even if you form a semiconductor device on one substrate and then transfer the semiconductor device to another substrate... Good. An example of a substrate on which a semiconductor device is placed is the one on which the transistor described above is formed. In addition to substrates that can be used, paper substrates, cellophane substrates, aramid film substrates, and polyimide film substrates are also available. Film substrates, stone substrates, wood substrates, fabric substrates (natural fibers (silk, cotton, linen), synthetic fibers (nylon) Polyurethane, polyester, or regenerated fibers (acetate, cupro, rayon) These include recycled polyester, leather substrates, or rubber substrates. By using plates, it is possible to manufacture flexible semiconductor devices and semiconductor devices that are less prone to breakage. This allows for the addition of heat resistance, weight reduction, or thinning of the material.

[0220] (Embodiment 5) In this embodiment, Figures 11 and 12 illustrate an example of an electronic device using a thin-film secondary battery. Then, I will explain.

[0221] Figure 11B shows an IC card, which is an example of an application device using the thin-film secondary battery according to the present invention. The power obtained by receiving radio wave 3005 is used in the thin-film secondary battery 3 shown in Figure 11A. It can be charged to 001. Inside IC card 3000 are an antenna and IC3004 Also, a thin-film secondary battery 3001 is located there. On the IC card 3000, the owner's I D3002 and photograph 3003 are attached. The thin-film secondary battery 3001 has been charged. It is also possible to use electricity to transmit signals such as authentication signals from the antenna.

[0222] Alternatively, an active matrix display device may be provided instead of the one shown in photograph 3003. Matrix display devices include reflective liquid crystal displays, organic EL displays, and electronic paper. It has the ability to display images (video or still images) and time on an active matrix display device. It is also possible. The power for the active matrix display device is supplied from the thin-film secondary battery 3001. They can provide it.

[0223] Since IC cards use plastic substrates, organic EL displays using flexible substrates are available. A display device is preferred.

[0224] Furthermore, solar cells may be installed. These cells absorb light upon exposure to ambient light, generate electricity, and then... The power can be used to charge the thin-film secondary battery 3001.

[0225] Furthermore, thin-film rechargeable batteries are not limited to IC cards, but are also used to power wireless sensors used in vehicles. It can be used as a power source, a secondary battery for MEMS devices, and the like.

[0226] Figure 12A shows an example of a wearable device. A wearable device has a power source and It uses a rechargeable battery. Furthermore, the user is responsible for water resistance during everyday use or outdoor use. To enhance this, in addition to wired charging where the connector part is exposed, wireless charging is also available. Wearable devices that can also operate electronically are in demand.

[0227] For example, a secondary battery can be mounted in a spectacle-type device 400 as shown in Figure 12A. The spectacle-type device 400 has a frame 400a and a display unit 400b. It has a curved shape. By incorporating a secondary battery into the temple of the frame 400a, it is lightweight and heavy This allows for a well-balanced, long-lasting glasses-type device 400. The thin-film secondary battery shown in Form 1 may be provided, and in order to accommodate space saving due to the miniaturization of the housing, It is possible to realize a configuration that can be achieved.

[0228] Furthermore, a rechargeable battery can be installed in the headset-type device 401. The device 401 comprises at least a microphone section 401a and a flexible pipe 401b, It has an earphone section 401c. Inside the flexible pipe 401b and the earphone section 401c A secondary battery can be installed inside. It may also be equipped with the thin-film secondary battery shown in Embodiment 1. Furthermore, it is possible to realize a configuration that can accommodate space savings due to the miniaturization of the enclosure.

[0229] Furthermore, a secondary battery can be installed in the device 402, which can be directly attached to the body. A secondary battery 402b can be installed inside the thin housing 402a of the vice 402. The device may also be equipped with a thin-film secondary battery as shown in Embodiment 1, which contributes to space saving due to the miniaturization of the housing. It is possible to implement a configuration that can handle the requirements.

[0230] Furthermore, a secondary battery can be installed in the device 403, which can be attached to clothing. A secondary battery 403b can be installed inside the thin housing 403a of S403. The device may also be equipped with the thin-film secondary battery shown in Embodiment 1, which helps to reduce space requirements due to the miniaturization of the housing. It is possible to realize the desired configuration.

[0231] Furthermore, a secondary battery can be mounted on the belt-type device 406. 06 has a belt portion 406a and a wireless power supply and receiving portion 406b, and the belt portion 406 A secondary battery can be installed inside a. The thin-film secondary battery shown in Embodiment 1 It can be equipped with features that allow for a configuration that can accommodate space-saving measures resulting from the miniaturization of the enclosure. ru.

[0232] Furthermore, a rechargeable battery can be installed in the wristwatch-type device 405. 05 has a display unit 405a and a belt unit 405b, and the display unit 405a or the belt unit 4 A secondary battery can be provided in 05b. The thin-film secondary battery shown in Embodiment 3 is provided. This allows for a configuration that can accommodate space savings resulting from the miniaturization of the enclosure.

[0233] The display unit 405a can display not only the time, but also various other information such as incoming emails and phone calls. It is possible.

[0234] Furthermore, the wristwatch-type device 405 is a wearable device that is worn directly on the wrist. Therefore, it may be equipped with sensors to measure the user's pulse, blood pressure, etc. Furthermore, it is possible to accumulate data related to health and use it to help maintain health.

[0235] A detailed explanation of the wristwatch-type device 405 shown in Figure 12A is provided below.

[0236] Figure 12B shows a perspective view of the wristwatch-type device 405 after it has been removed from the arm.

[0237] A side view is also shown in Figure 12C. Figure 12C shows the internal structure with the secondary battery 913. This shows that the secondary battery 913 is the thin-film secondary battery shown in Embodiment 3. Secondary battery The 913 is positioned to overlap with the display unit 405a, and is small and lightweight. [Explanation of symbols]

[0238] 101: Substrate, 201: Positive electrode, 202: Solid electrolyte layer, 203: Negative electrode, 204: Positive electrode active material 205: Negative electrode active material layer, 206: Protective layer, 400: Eyeglass-type device, 400a: F Frame, 400b: Display unit, 401: Headset-type device, 401a: Microphone unit, 4 01b: Flexible pipe, 401c: Earphone section, 402: Device, 402a: Enclosure, 402b: secondary battery, 403: device, 403a: enclosure, 403b: secondary battery, 405: Wristwatch-type device, 405a: Display unit, 405b: Strap unit, 406: Strap type Device, 406a: Belt section, 406b: Wireless power supply / receiving section, 3000: IC car D, 3001: Thin-film secondary battery, 3002: ID, 3003: Photo, 3004: IC, 3 005: Radio Waves

Claims

1. The positive electrode active material layer, A negative electrode active material layer is disposed opposite the positive electrode active material layer, The positive electrode active material layer and the negative electrode active material layer are separated by a solid electrolyte layer containing silicon, oxygen, lithium, and carbon. A solid-state secondary battery in which the ratio of oxygen to silicon (O / Si) in the solid electrolyte layer is greater than 1 and less than 2.

2. The positive electrode active material layer, A negative electrode active material layer is disposed opposite the positive electrode active material layer, The positive electrode active material layer and the negative electrode active material layer are separated by a solid electrolyte layer having silicon, oxygen, lithium, and carbon. A solid-state secondary battery in which the ratio of oxygen to silicon in the solid electrolyte layer (O / Si), determined from EDX measurement results on the cross-section of the solid electrolyte layer, is greater than 1 and less than 2.

3. A solid-state secondary battery according to claim 1 or claim 2, wherein the solid electrolyte layer further comprises nitrogen.

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