Film forming device

Abstract

This film formation device comprises: a vacuum chamber; a substrate support part that supports a substrate in the vacuum chamber; a target support part that supports a target which includes gallium and nitrogen in the vacuum chamber; a sputtering gas supply part that supplies a sputtering gas to the vacuum chamber; a sputtering power supply that applies a voltage to the target; a first radical supply source that is capable of supplying to the vacuum chamber a nitrogen radical generated from N2 gas and / or a hydrogen radical generated from H2 gas; a second radical supply source that is capable of supplying to the vacuum chamber a SiH3radical; and a control part that controls the sputtering gas supply part, the sputtering power supply, the first radical supply source, and the second radical supply source.

Description

[Technical Field]

[0001] One embodiment of the present invention relates to a film deposition apparatus for depositing gallium nitride films. [Background technology]

[0002] In small and medium-sized display devices such as smartphones, display devices using liquid crystal displays (LCDs) and OLEDs (Organic Light Emitting Diodes) have already been commercialized. Among these, OLED display devices, which use self-emissive elements, have the advantage of high contrast and no backlight compared to liquid crystal display devices. However, because OLEDs are composed of organic compounds, it is difficult to ensure high reliability of OLED display devices due to the degradation of these organic compounds.

[0003] In recent years, development has been progressing on so-called micro-LED displays or mini-LED displays, which are next-generation display devices that incorporate tiny LED chips within the pixels of a circuit board. LEDs are self-emissive elements similar to OLEDs, but unlike OLEDs, they are composed of stable inorganic compounds containing gallium (Ga) or indium (In), making it easier to ensure high reliability in micro-LED displays compared to OLED displays. Furthermore, LED chips have high luminous efficiency, enabling high brightness. Therefore, micro-LED displays or mini-LED displays are expected to be next-generation display devices with high reliability, high brightness, and high contrast.

[0004] Incidentally, gallium nitride films used in micro-LEDs and the like are generally deposited on sapphire substrates at high temperatures of 800°C to 1000°C using MOCVD (Metal Organic Chemical Vapor Deposition) or HVPE (Hydride Vapor Phase Epitaxy). However, in recent years, a method for depositing gallium nitride films by sputtering, which allows for deposition at relatively low temperatures, has been developed (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-164927 [Overview of the project] [Problems that the invention aims to solve]

[0006] Micro-LEDs require the formation of n-type and p-type semiconductor layers. However, controlling the dopants in gallium nitride films, which are deposited at low temperatures, has been a challenge.

[0007] One embodiment of the present invention aims to provide a film deposition apparatus that improves the controllability of dopants in gallium nitride films deposited at low temperatures, in view of the above-mentioned problems. [Means for solving the problem]

[0008] A film deposition apparatus according to one embodiment of the present invention includes a vacuum chamber capable of creating a vacuum inside; a substrate support section provided inside the vacuum chamber and supporting a substrate; a target support section provided inside the vacuum chamber and supporting a target containing nitrogen and gallium; a sputtering gas supply section connected to the vacuum chamber and supplying sputtering gas to the vacuum chamber; a sputtering power supply for applying a voltage to the target; a first radical supply source connected to the vacuum chamber and capable of supplying at least one of nitrogen radicals generated from N2 gas and hydrogen radicals generated from H2 gas to the vacuum chamber; a second radical supply source connected to the vacuum chamber and capable of supplying SiH3 radicals to the vacuum chamber; and a control section for controlling the sputtering gas supply section, the sputtering power supply, the first radical supply source, and the second radical supply source.

[0009] A film deposition apparatus according to one embodiment of the present invention includes a vacuum chamber capable of creating a vacuum inside; a substrate support section provided inside the vacuum chamber and supporting a substrate; a target support section provided inside the vacuum chamber and supporting a target containing nitrogen and gallium; a sputtering gas supply section connected to the vacuum chamber and supplying sputtering gas to the vacuum chamber; a sputtering power supply for applying a voltage to a first target; a radical supply source connected to the vacuum chamber and capable of supplying at least one of nitrogen radicals generated from N2 gas and hydrogen radicals generated from H2 gas to the vacuum chamber; a dopant supply source connected to the vacuum chamber and capable of supplying dopants to the vacuum chamber; and a control section for controlling the sputtering gas supply section, the second sputtering power supply, the radical supply source, and the dopant supply source. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the configuration of a film deposition apparatus according to one embodiment of the present invention. [Figure 2] This is a block diagram showing the connection relationships of the control unit of a film deposition apparatus according to one embodiment of the present invention. [Figure 3] This flowchart shows a method for depositing a gallium nitride film using a film deposition apparatus according to one embodiment of the present invention. [Figure 4] This is a sequence diagram showing a method for depositing a gallium nitride film using a film deposition apparatus according to one embodiment of the present invention. [Figure 5] This is a flowchart for a method of depositing a gallium nitride film using a film deposition apparatus according to one embodiment of the present invention, in which the supply and cessation of nitrogen radicals and hydrogen radicals occur simultaneously. [Figure 6] This is a flowchart illustrating a method for depositing gallium nitride using a film deposition apparatus according to one embodiment of the present invention, showing different cases for the supply and cessation of nitrogen radicals and hydrogen radicals. [Figure 7]In the method for forming a gallium nitride film using a film forming apparatus according to an embodiment of the present invention, it is a flowchart when the supply and stop of nitrogen radicals and hydrogen radicals are different. [Figure 8] It is a schematic diagram showing a part of the configuration of a film forming apparatus according to an embodiment of the present invention. [Figure 9] It is a sequence diagram showing a method for forming a gallium nitride film using a film forming apparatus according to an embodiment of the present invention. [Figure 10] It is a sequence diagram showing a method for forming a gallium nitride film using a film forming apparatus according to an embodiment of the present invention. [Figure 11] It is a schematic diagram showing the configuration of a film forming apparatus according to an embodiment of the present invention. [Figure 12] It is a flowchart showing a method for forming a gallium nitride film using a film forming apparatus according to an embodiment of the present invention. [Figure 13] It is a sequence diagram showing a method for forming a gallium nitride film using a film forming apparatus according to an embodiment of the present invention. [Figure 14] It is a schematic diagram showing the configuration of a light emitting device according to an embodiment of the present invention. [Figure 15] It is a flowchart showing a method for manufacturing a light emitting device according to an embodiment of the present invention. [Figure 16] It is a schematic diagram showing the configuration of a semiconductor device according to an embodiment of the present invention. [Figure 17] It is a flowchart showing a method for manufacturing a semiconductor device according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0011] The embodiments of the present invention will be described below with reference to the drawings. Note that each embodiment is merely an example, and any embodiment that a person skilled in the art could easily conceive by modifying it appropriately while maintaining the spirit of the invention is naturally included within the scope of the present invention. Furthermore, in order to clarify the explanation, the drawings may schematically represent the width, thickness, or shape of each part compared to the actual embodiment. However, the illustrated shapes are merely examples and do not limit the interpretation of the present invention.

[0012] In this specification, expressions such as "α includes A, B, or C," "α includes any one of A, B, and C," and "α includes one selected from the group consisting of A, B, and C" do not exclude cases where α includes multiple combinations of A, B, and C, unless otherwise explicitly stated. Furthermore, these expressions do not exclude cases where α includes other elements.

[0013] In this specification, for the sake of explanation, the terms "up" or "above" or "down" or "below" will be used. However, as a general rule, the substrate on which the structure is formed is used as the reference point, and the direction from the substrate toward the structure is defined as "up" or "above." Conversely, the direction from the structure toward the substrate is defined as "down" or "below." Therefore, in the expression "structure on a substrate," the surface of the structure facing the substrate is the bottom surface of the structure, and the opposite surface is the top surface of the structure. Furthermore, the expression "structure on a substrate" merely describes the hierarchical relationship between the substrate and the structure, and other components may be placed between the substrate and the structure. In addition, the terms "up" or "above" or "down" or "below" refer to the stacking order in a structure with multiple layers, and do not necessarily mean that the layers are in a superimposed positional relationship in a plan view.

[0014] In this specification, the letters such as "1st," "2nd," or "3rd" attached to each component are merely convenient indicators used to distinguish each component, and unless otherwise specified, they have no further meaning.

[0015] In this specification and in the drawings, the same reference numeral is used to refer to multiple identical or similar components collectively, and lowercase or uppercase letters may be used to distinguish each of these components. Furthermore, hyphens and natural numbers may be used to distinguish multiple parts of a single component.

[0016] In this specification, cations and anions may be referred to as positive ions and negative ions, respectively.

[0017] The following embodiments can be combined with each other, provided that no technical inconsistencies arise.

[0018] <First Embodiment> Referring to Figures 1 to 7, a film deposition apparatus 10 according to one embodiment of the present invention will be described.

[0019] [1. Configuration of the film deposition apparatus 10] Figure 1 is a schematic diagram showing the configuration of a film deposition apparatus 10 according to one embodiment of the present invention. The film deposition apparatus 10 can be used to form gallium nitride films, primarily containing an n-type dopant. For convenience, the configuration of the film deposition apparatus 10 will be described below assuming that the n-type dopant of the gallium nitride film is silicon. However, the n-type dopant is not limited to silicon.

[0020] As shown in Figure 1, the film deposition apparatus 10 comprises a vacuum chamber 100, a substrate support section 110, a heating section 120, a target 130, a target support section 140, a pump 150, a sputtering power supply 160, a sputtering gas supply section 170, a first radical supply source 180, a second radical supply source 190, and a control unit 200.

[0021] The vacuum chamber 100 contains a substrate support section 110, a heating section 120, a target 130, and a target support section 140. The substrate support section 110 and the heating section 120 are located at the bottom of the vacuum chamber 100. The substrate is placed on the substrate support section 110. The heating section 120 is located inside the substrate support section 110 and can heat the substrate placed on the substrate support section 110. The target 130 and the target support section 140 are located at the top of the vacuum chamber 100. The target 130 is supported by the target support section 140 and is positioned to face the substrate placed on the substrate support section 110.

[0022] In Figure 1, the substrate support section 110 and heating section 120 are located at the bottom of the vacuum chamber 100, while the target 130 and target support section 140 are located at the top of the vacuum chamber 100. However, the positions of these components may be reversed.

[0023] Target 130 is gallium nitride containing nitrogen and gallium. Preferably, the composition ratio of gallium nitride in target 130 is 0.5 to 2 for gallium relative to nitrogen. Since the nitrogen for the gallium nitride film deposited on the substrate is supplied from target 130 and the first radical supply source 180, while the gallium for the gallium nitride film is supplied only from target 130, it is even more preferable that the composition of gallium nitride in target 130 has more gallium than nitrogen.

[0024] Outside the vacuum chamber 100, there are a pump 150, a sputtering power supply 160, a sputtering gas supply unit 170, a first radical supply source 180, and a second radical supply source 190.

[0025] Pump 150 is connected to the vacuum chamber 100 via piping 151. Pump 150 can evacuate the gas inside the vacuum chamber 100 through piping 151. In other words, the vacuum chamber 100 can be evacuated by pump 150 connected to the vacuum chamber 100. Furthermore, the pressure inside the vacuum chamber 100 can be kept constant by opening and closing valve 152 connected to piping 151. As pump 150, for example, a turbomolecular pump or a cryopump can be used.

[0026] The sputtering power supply 160 is electrically connected to the target 130 via wiring 161. The sputtering power supply 160 can generate a direct current (DC) voltage or an alternating current (AC) voltage and apply the generated voltage to the target 130. The frequency of the AC voltage is 13.56 MHz. The sputtering power supply 160 can also apply a bias voltage to the target 130 and further apply a DC or AC voltage.

[0027] The sputtering power supply 160 may periodically change the voltage applied to the target 130. For example, a voltage may be applied to the target 130 for a period of 1 μsec to 1 msec, and then the application of the voltage to the target 130 may be stopped for a period of 1 msec to 100 msec. In the film deposition apparatus 10, the period during which a voltage is applied to the target 130 and the period during which the application of the voltage to the target 130 is stopped are repeated, and a gallium nitride film is deposited. In the following, the state in which a voltage is applied to the target 130 may be referred to as the ON state of the sputtering power supply 160, and the state in which no voltage is applied to the target 130 may be referred to as the OFF state of the sputtering power supply 160.

[0028] The sputtering gas supply unit 170 is connected to the vacuum chamber 100 via piping 171. The sputtering gas supply unit 170 can supply sputtering gas into the vacuum chamber 100 via piping 171. The flow rate of the sputtering gas can also be controlled by a mass flow controller 172 connected to piping 171. Argon (Ar) or krypton (Kr) can be used as the sputtering gas supplied from the sputtering gas supply unit 170.

[0029] The first radical source 180 is connected to a pipe 181 located inside the vacuum chamber 100. A nitrogen gas supply unit 182 is connected to the first radical source 180 via pipe 184, and a hydrogen gas supply unit 183 is connected via pipe 185. The nitrogen gas supply unit 182 can supply nitrogen gas (N2 gas) to the first radical source 180 through pipe 184. The hydrogen gas supply unit 183 can supply hydrogen gas (H2 gas) to the first radical source 180 through pipe 185. In other words, the film deposition apparatus 10 can supply N2 gas and H2 gas to the first radical source 180 through separate pipes.

[0030] A first plasma power supply 186 is connected to the first radical supply source 180. The first plasma power supply 186 can radicalize the N2 gas and H2 gas supplied to the first radical supply source 180. In other words, the first radical supply source 180 can generate nitrogen radicals and hydrogen radicals from the N2 gas and H2 gas, respectively. The nitrogen radicals and hydrogen radicals generated in the first radical supply source 180 are supplied to the vacuum chamber 100 through piping 181. One end of piping 181 may be directed toward the substrate support 110. In this case, nitrogen radicals and hydrogen radicals can be irradiated from one end of piping 181 toward the substrate placed on the substrate support 110.

[0031] The second radical source 190 is connected to piping 191 located within the vacuum chamber 100. A doping gas supply unit 192 is also connected to the second radical source 190 via piping 193. The doping gas supply unit 192 can supply doping gas to the second radical source 190 through piping 193. The doping gas is, for example, silane gas (SiH4 gas).

[0032] A second plasma power supply 194 is connected to the second radical source 190. The second plasma power supply 194 receives SiH4 gas from the second radical source 190. x (x=1~3) radicals can be generated. Furthermore, the second radical source 190 can selectively generate only SiH3 radicals by utilizing the differences in the lifetimes of each radical. In other words, the second radical source 190 can generate SiH3 radicals from SiH4 gas. The SiH3 radicals generated by the second radical source 190 are supplied to the vacuum chamber 100 through the piping 193. One end of the piping 191 may be directed toward the substrate support 110. In this case, SiH3 radicals can be irradiated from one end of the piping 191 toward the substrate placed on the substrate support 110.

[0033] The first radical source 180 and the second radical source 190 may be provided inside the vacuum chamber 100.

[0034] The control unit 200 can control the operation of the film deposition apparatus 10 during the deposition of a gallium nitride film. The control unit 200 is a computer capable of performing arithmetic processing using data or information, and includes, for example, a central processing unit (CPU), a microprocessor (MPU), or random access memory (RAM). Specifically, the control unit 200 controls the operation of the film deposition apparatus 10 by executing a predetermined program. Here, with reference to Figure 2, the details of the control of the control unit 200 will be described.

[0035] Figure 2 is a block diagram showing the connection relationships of the control unit 200 of the film deposition apparatus 10 according to one embodiment of the present invention.

[0036] As shown in Figure 2, the control unit 200 is connected to the sputtering power supply 160 and the sputtering gas supply unit 170. Therefore, the control unit 200 can control the ON or OFF state of the sputtering power supply 160 and the start or stop of the supply of sputtering gas to the vacuum chamber 100. In Figure 2, the control unit 200 is shown as being connected to the sputtering gas supply unit 170, but the control unit 200 may also be connected to a mass flow controller 172, and the start or stop of the sputtering gas supply may be controlled by the mass flow controller 172.

[0037] Furthermore, the control unit 200 is connected to the nitrogen gas supply unit 182, the hydrogen gas supply unit 183, and the first plasma power supply 186. Therefore, the control unit 200 can control the start or stop of the supply of N2 gas to the first radical supply source 180, the start or stop of the supply of H2 gas to the first radical supply source 180, and the start or stop of the generation of nitrogen radicals or hydrogen radicals. When nitrogen radicals or hydrogen radicals are not generated in the first radical supply source 180, N2 gas or H2 gas can be supplied to the vacuum chamber 100. In other words, by being controlled by the control unit 200, the first radical supply source 180 can supply at least one of N2 gas, H2 gas, nitrogen radicals, and hydrogen radicals to the vacuum chamber 100. For convenience, in the following explanation, the control unit 200 may be described as controlling the first radical supply source 180.

[0038] Furthermore, the control unit 200 is connected to the doping gas supply unit 192 and the second plasma power supply 194. Therefore, the control unit 200 can control the start or stop of the supply of doping gas to the second radical supply source 190, and the start or stop of SiH3 radical generation. When SiH3 radicals are not generated in the second radical supply source 190, SiH4 gas can be supplied to the vacuum chamber 100. In other words, the second radical supply source 190 can supply SiH4 gas or SiH3 radicals to the vacuum chamber 100 under the control of the control unit 200. For convenience, in the following explanation, it may be described as if the control unit 200 controls the second radical supply source 190.

[0039] Furthermore, the control unit 200 may control the pump 150 so that the inside of the vacuum chamber 100 is maintained at a predetermined pressure. The control unit 200 may also control the heating unit 120 so that the substrate placed on the substrate support unit 110 is heated to a predetermined temperature.

[0040] Furthermore, the film deposition apparatus 10 can also deposit nitride films other than gallium nitride films by using a material other than gallium nitride for the target 130.

[0041] [2. Method for forming gallium nitride films] Figure 3 is a flowchart showing a method for depositing a gallium nitride film using a film deposition apparatus 10 according to one embodiment of the present invention. In the gallium nitride film deposition method shown in Figure 3, steps S100 to S190 are executed sequentially.

[0042] In step S100, the substrate is placed on the substrate support portion 110 so as to face the target 130. In the film deposition apparatus 10, for example, a glass substrate or a quartz substrate can be used as the substrate. Alternatively, a glass substrate or a quartz substrate on which a titanium film or an aluminum nitride film has been formed can also be used as the substrate.

[0043] In step S110, the substrate is heated to a predetermined temperature by the heating unit 120. The predetermined temperature is, for example, 400°C or more and 600°C or less.

[0044] In step S120, the pump 150 evacuates the gas from the vacuum chamber 100 so that the vacuum level is below a predetermined level. The predetermined vacuum level is, for example, 10 -6 Pa is the most common answer, but it is not limited to this.

[0045] In step S130, the first radical source 180 is controlled, and nitrogen radicals and hydrogen radicals are supplied from the first radical source 180 to the vacuum chamber 100.

[0046] In step S140, the sputtering gas supply unit 170 is controlled, and sputtering gas is supplied from the sputtering gas supply unit 170 to the vacuum chamber 100. The flow rate of the sputtering gas is also adjusted by the mass flow controller 172 so that the pressure inside the vacuum chamber 100 is a predetermined pressure. The predetermined pressure is, for example, between 0.1 Pa and 10 Pa.

[0047] In step S150, the sputtering power supply 160 is controlled, and a predetermined voltage is applied to the target 130 so that the target 130 acts as the cathode relative to the substrate (the sputtering power supply 160 is turned on). This causes the sputtering gas supplied to the vacuum chamber 100 to be plasma-generated, generating cations and electrons in the sputtering gas. The ions in the sputtering gas are accelerated by the potential difference between the substrate and the target 130 and collide with the target 130. As a result, sputtered gallium and gallium cations are emitted from the target 130.

[0048] In step S150, nitrogen radicals are supplied to the vacuum chamber 100 from the first radical source 180. As a result, gallium released from the target 130 recombines with the nitrogen radicals to produce gallium nitride. The generated gallium nitride is deposited on the substrate to form a gallium nitride film.

[0049] In step S150, gallium nitride is also produced by another recombination reaction. Nitrogen has high electronegativity and readily attracts electrons. Therefore, nitrogen radicals react with electrons in the vacuum chamber 100 to produce nitrogen anions. The produced nitrogen anions recombine with gallium cations present near the substrate to produce gallium nitride. The produced gallium nitride is deposited on the substrate, forming a gallium nitride film on the substrate. The recombination reaction of cations and anions is a reaction that releases a large amount of energy. Therefore, even at low substrate temperatures, the thermal energy from the recombination reaction allows for the formation of a high-quality gallium nitride film on the substrate.

[0050] Incidentally, oxygen may remain in the vacuum chamber 100. In this case, gallium cations react with the residual oxygen in the vacuum chamber 100 to produce gallium oxide. Since the growth of the gallium nitride film is inhibited when gallium oxide is produced, it is preferable that the residual oxygen in the vacuum chamber 100 be reduced as much as possible. In step S150, not only nitrogen radicals but also hydrogen radicals are supplied to the vacuum chamber 100. The hydrogen radicals react with the residual oxygen to produce water (water vapor). The produced water vapor is then exhausted from the vacuum chamber 100 by the pump 150. In other words, in the film deposition apparatus 10, the residual oxygen in the vacuum chamber 100 is reduced, so the production of gallium oxide is suppressed, and as a result, the gallium nitride film formed on the substrate is a high-quality film.

[0051] As mentioned above, hydrogen radicals have the effect of removing residual oxygen that inhibits the formation of gallium nitride. Furthermore, hydrogen radicals can react with gallium cations to produce gallium hydride cations. Gallium hydride cations are highly reactive and readily react with nitrogen anions to produce gallium nitride. Therefore, hydrogen radicals also have the effect of promoting the formation of gallium nitride.

[0052] In step S160, the sputtering power supply 160 is controlled, and the application of voltage to the target 130 is stopped (the sputtering power supply 160 is turned off). As a result, the plasma disappears, but the deposition apparatus 10 can still generate gallium nitride in this state. Specifically, in step S160, gallium nitride can be generated by utilizing the metastable state of the sputtering gas (noble gas). The details of gallium nitride generation in step S160 will now be explained.

[0053] It is known that long-lived metastable noble gas atoms exist in noble gas plasmas. For example, the metastable state energies of argon and krypton atoms are 11.61 eV and 9.91 eV, respectively. Such metastable argon or krypton atoms are generated in the sputtering plasma and, due to their long lifetime, can persist even after the plasma has disappeared. In other words, metastable argon or krypton atoms can persist even after the application of voltage to the target 130 is stopped.

[0054] After the voltage application to target 130 is stopped, nitrogen molecules, as well as nitrogen radicals, are present in the vacuum chamber 100. The dissociation energy from nitrogen molecules to nitrogen atoms due to electron collisions is 9.756 eV, which is close to the metastable state energy of argon or krypton atoms. Therefore, when nitrogen molecules collide with metastable argon or krypton atoms, a dissociation reaction of the nitrogen molecules occurs, generating nitrogen radicals. In other words, even after the voltage application to target 130 is stopped, nitrogen radicals are generated by metastable argon or krypton atoms. As mentioned above, nitrogen has high electronegativity, so nitrogen radicals react with electrons in the vacuum chamber 100 to generate nitrogen anions. In step S160, nitrogen radicals are supplied to the vacuum chamber 100 from the first radical supply source 180. The supplied nitrogen radicals react with electrons in the vacuum chamber 100 to generate nitrogen anions. The nitrogen anions generated in this way recombine with gallium cations present near the substrate to produce gallium nitride. The generated gallium nitride is deposited on the substrate, forming a gallium nitride film.

[0055] Therefore, in step S160, gallium nitride can be efficiently produced by utilizing not only nitrogen radicals supplied from the first radical source 180, but also metastable argon atoms or krypton atoms.

[0056] In step S170, the first radical source 180 is controlled, and the supply of nitrogen radicals and hydrogen radicals to the vacuum chamber 100 is stopped.

[0057] In step S180, the second radical source 190 is controlled, and SiH3 radicals are supplied from the second radical source 190 to the vacuum chamber 100. The SiH3 radicals react with the gallium nitride film formed on the substrate, and silicon is added to the gallium nitride film. SiH3 radicals have a long lifespan. Also, in step S180, N2 gas or nitrogen radicals are not supplied to the vacuum chamber 100. Therefore, the mean free path of the SiH3 radicals in the vacuum chamber 100 is large, and they can react efficiently with the gallium nitride film on the substrate. In other words, silicon can be added to the gallium nitride film efficiently.

[0058] Furthermore, the second radical source 190 generates not only SiH3 radicals but also hydrogen radicals. Therefore, in step S180, the hydrogen radicals react with residual oxygen, further reducing the residual oxygen in the vacuum chamber 100. In addition, the hydrogen radicals can reduce gallium oxide near the surface of the gallium nitride film. Thus, the reaction of SiH3 with gallium oxide is suppressed, and silicon can be efficiently doped into the gallium nitride film.

[0059] In step S190, the second radical source 190 is controlled, and the supply of SiH3 radicals to the vacuum chamber 100 is stopped.

[0060] By repeating steps S130 to S190, a gallium nitride film with silicon added can be formed on the substrate. Now, with reference to Figure 4, the details of the timing of control by the control unit 200 will be explained.

[0061] Figure 4 is a sequence diagram showing a method for depositing a gallium nitride film using a film deposition apparatus 10 according to one embodiment of the present invention.

[0062] Figure 4 shows a first period T1 for depositing a gallium nitride film and a second period T2 for adding silicon to the gallium nitride film. In the film deposition apparatus 10, the first period T1 and the second period T2 are repeated to deposit a gallium nitride film with an n-type dopant. Since the second period T2 is the period for adding the n-type dopant to the gallium nitride film, the second period T2 may be shorter than the first period T1.

[0063] During the first period T1, the supply of nitrogen radicals and hydrogen radicals is initiated, followed by the supply of sputtering gas. Subsequently, the sputtering power supply 160 is turned on, and a gallium nitride film is deposited. Also during the first period T1, the sputtering power supply 160 is turned off, and the supply of sputtering gas is stopped. Subsequently, the supply of nitrogen radicals and hydrogen radicals is stopped.

[0064] The supply and cessation of nitrogen radicals and hydrogen radicals during the first period T1 may occur simultaneously or separately. The cases where the supply and cessation of nitrogen radicals and hydrogen radicals occur simultaneously and separately will be explained with reference to Figures 5 to 7.

[0065] Figure 5 is a flowchart of a method for depositing a gallium nitride film using a film deposition apparatus 10 according to one embodiment of the present invention, in which the supply and cessation of nitrogen radicals and hydrogen radicals occur simultaneously. As shown in Figure 5, steps S500 to S550 are executed sequentially.

[0066] In step S500, N2 gas is supplied from the nitrogen gas supply unit 182 to the first radical supply source 180. At this time, the N2 gas supplied to the first radical supply source 180 may also be supplied to the vacuum chamber 100.

[0067] In step S510, H2 gas is supplied from the hydrogen gas supply unit 183 to the first radical supply source 180. At this time, the H2 gas supplied to the first radical supply source 180 can also be supplied to the vacuum chamber 100.

[0068] In step S520, the first plasma power supply 186 is turned on, and nitrogen radicals and hydrogen radicals are generated from the N2 gas and H2 gas supplied to the first radical supply source 180, respectively. As a result, nitrogen radicals and hydrogen radicals are generated simultaneously and can be supplied to the vacuum chamber 100 at the same time.

[0069] In step S530, the first plasma power supply 186 is turned off, and the supply of nitrogen radicals and hydrogen radicals to the vacuum chamber 100 is stopped. At this time, the N2 gas and H2 gas supplied to the first radical supply source 180 can also be supplied to the vacuum chamber 100.

[0070] In step S540, the supply of H2 gas from the hydrogen gas supply unit 183 to the first radical supply source 180 is stopped.

[0071] In step S550, the supply of N2 gas from the nitrogen gas supply unit 182 to the first radical supply source 180 is stopped.

[0072] Figures 6 and 7 are flowcharts showing different cases of supplying and stopping nitrogen radicals and hydrogen radicals in a gallium nitride film deposition method using a film deposition apparatus 10 according to one embodiment of the present invention. As shown in Figures 6 and 7, the method includes steps S600 to S650.

[0073] In step S600, N2 gas is supplied from the nitrogen gas supply unit 182 to the first radical supply source 180. At this time, the N2 gas supplied to the first radical supply source 180 may also be supplied to the vacuum chamber 100.

[0074] In step S610, the first plasma power supply 186 is turned on, and nitrogen radicals are generated from the N2 gas supplied to the first radical source. The generated nitrogen radicals are supplied to the vacuum chamber 100. At this point, hydrogen radicals are not supplied to the vacuum chamber 100.

[0075] In step S620, H2 gas is supplied from the hydrogen gas supply unit 183 to the first radical supply source 180. Hydrogen radicals are also generated from the H2 gas supplied to the first radical supply source 180. The generated hydrogen radicals are supplied to the vacuum chamber 100. This allows hydrogen radicals to be supplied to the vacuum chamber 100 at a different timing than nitrogen radicals.

[0076] In step S630, the supply of H2 gas from the hydrogen gas supply unit 183 to the first radical supply source 180 is stopped. This stops the supply of hydrogen radicals to the vacuum chamber 100. At this point, nitrogen radicals are being supplied to the vacuum chamber 100.

[0077] In step S640, the first plasma power supply 186 is turned off, and the supply of nitrogen radicals to the vacuum chamber 100 is stopped. This allows the supply of nitrogen radicals to the vacuum chamber 100 to be stopped at a different timing than that of hydrogen radicals. Alternatively, the N2 gas supplied to the first radical supply source 180 can also be supplied to the vacuum chamber 100.

[0078] In step S650, the supply of N2 gas from the nitrogen gas supply unit 182 to the first radical supply source 180 is stopped.

[0079] The flowchart shown in Figure 7 is the same as the flowchart in Figure 6, but with the start and stop timings of the N2 gas supply and the H2 gas supply reversed. Since the other configurations are the same, the explanation of the flowchart in Figure 7 is omitted.

[0080] Returning to Figure 4, let's explain the second period, T2.

[0081] During the second period T2, SiH3 radicals are supplied to the vacuum chamber 100 from the second radical source 190. At this time, nitrogen radicals are not supplied to the vacuum chamber 100 from the first radical source 180. Therefore, no reaction occurs between SiH3 radicals and nitrogen radicals, and the SiH3 radicals efficiently react with the gallium nitride film on the substrate, allowing silicon to be added to the gallium nitride film. Subsequently, the supply of SiH3 radicals from the second radical source 190 to the vacuum chamber 100 is stopped. The supply period of SiH3 radicals is between 1 μsec and 100 μsec.

[0082] As described above, in the film deposition apparatus 10, during the first period T1, a gallium nitride film is deposited on the substrate using nitrogen radicals and hydrogen radicals from the first radical supply source 180, and during the second period T2, silicon is added to the gallium nitride film on the substrate using SiH3 radicals from the second radical supply source 190. During the second period T2, since no nitrogen radicals are present in the vacuum chamber 100, the SiH3 radicals can react efficiently with the gallium nitride film. Therefore, the controllability of n-type dopants in the gallium nitride film is improved in the film deposition apparatus 10.

[0083] <Example 1> The film deposition apparatus 10 is not limited to the configuration shown in Figure 1. Below, with reference to Figure 8, the configuration of film deposition apparatus 10A, which is a modified example of film deposition apparatus 10, will be described. Note that when the configuration of film deposition apparatus 10A is the same as that of film deposition apparatus 10, the description of the configuration of film deposition apparatus 10A may be omitted.

[0084] Figure 8 is a schematic diagram showing a part of the configuration of a film deposition apparatus 10A according to one embodiment of the present invention.

[0085] As shown in Figure 8, a retractable pipe 195A is provided between the second radical source 190 and pipe 191. SiH3 radicals generated in the second radical source 190 are supplied to the vacuum chamber 100 through pipes 195A and 191. Increasing the length of pipe 195A makes it easier for SiH3 radicals to be deactivated within pipes 195A and 191. As a result, the amount of SiH3 radicals supplied to the vacuum chamber 100 decreases. In other words, the amount of SiH3 radicals that reach the substrate can be adjusted by adjusting the length of pipe 195A.

[0086] The pipe 195A may be a pipe that expands and contracts to slide relative to the pipe 191, or it may be a bellows pipe.

[0087] As explained above, in the film deposition apparatus 10A, the amount of SiH3 radicals supplied to the vacuum chamber 100 can be adjusted by changing the distance from the second radical supply source 190 to one end of the piping 191 in the vacuum chamber 100. This allows for controllable adjustment of the amount of n-type dopant added to the gallium nitride film. Therefore, the controllability of n-type dopant in the gallium nitride film is improved in the film deposition apparatus 10A.

[0088] <Modification 2> The timing of control by the control unit 200 is not limited to the configuration shown in Figure 4. Refer to Figure 9 to explain another timing of control by the control unit 200. Note that if the configuration shown in Figure 9 is the same as the configuration shown in Figure 4, the explanation of the configuration shown in Figure 9 may be omitted.

[0089] Figure 9 is a sequence diagram showing a method for depositing a gallium nitride film using a film deposition apparatus 10 according to one embodiment of the present invention.

[0090] As shown in Figure 9, during the second period T2', SiH3 radicals are supplied from the second radical source 190 to the vacuum chamber 100, along with sputtering gas, and the sputtering power supply 160 is turned on. In this case, gallium nitride is sputtered from the target, but since nitrogen radicals are not supplied to the vacuum chamber 100, gallium nitride with a higher concentration of gallium than nitrogen is deposited on the substrate. As a result, the surface of the gallium nitride film on the substrate becomes predominantly gallium, and the SiH3 radicals react with the gallium on the gallium surface, resulting in a substitution of gallium with silicon. Therefore, silicon can be efficiently added to the gallium nitride film. In this case, the silicon concentration incorporated into the gallium nitride film changes periodically in the film thickness direction.

[0091] In the second period T2', it is not necessary to actively sputter gallium nitride. Therefore, it is preferable that the power of the sputtering power supply 160 in the second period T2' is smaller than the power of the sputtering power supply 160 in the first period T1.

[0092] As explained above, in the second period T2', by sputtering gallium nitride without supplying nitrogen radicals, n-type dopants can be efficiently added to the gallium nitride film, improving the controllability of the n-type dopant.

[0093] <Variation 3> The gallium plane on the gallium nitride surface on the substrate may be formed at times other than the second period T2'. Another timing of control by the control unit 200 will be described with reference to Figure 10. Note that if the configuration shown in Figure 10 is the same as the configuration shown in Figure 4 or Figure 9, the description of the configuration shown in Figure 10 may be omitted.

[0094] Figure 10 is a sequence diagram showing a method for depositing a gallium nitride film using a film deposition apparatus 10 according to one embodiment of the present invention.

[0095] As shown in Figure 10, in the first period T1', the sputtering power supply is turned off after the supply of nitrogen radicals and hydrogen radicals from the first radical source 180 is stopped. Therefore, the first period T1' includes the period during which gallium nitride is sputtered from the target even after the supply of nitrogen radicals and hydrogen radicals has stopped. During this period, since nitrogen radicals are not supplied to the vacuum chamber 100, gallium nitride with more gallium than nitrogen is deposited on the substrate. That is, the surface of the gallium nitride film on the substrate becomes predominantly gallium. Subsequently, in the second period T2, when SiH3 radicals are supplied to the vacuum chamber 100, they react with the gallium on the gallium surface formed in the first period T1', and gallium is replaced by silicon. Therefore, silicon can be efficiently added to the gallium nitride film.

[0096] As explained above, by forming a gallium nitride film having a gallium surface in the first period T1', and reacting the gallium on the gallium surface with SiH3 radicals in the second period T2, n-type dopants can be efficiently added to the gallium nitride film, improving the controllability of the n-type dopant.

[0097] <Modification 4> The doping gas supplied from the doping gas supply unit 192 is not limited to SiH4 gas. A doping gas in which XeF2 gas is added to SiH4 (SiH4 / XeF2 mixed gas) may also be used. XeF2 undergoes collisions with electrons to form metastable Xe * And an F radical is formed. Metastable state of Xe * The energy is 8.32 eV. This value is close to the dissociation energy of SiH4, which is 8.75 eV. Therefore, in the second radical source 190, metastable Xe * From this source, SiH3 radicals are selectively generated. In addition, F radicals have high electronegativity and can extract hydrogen from SiH4. Therefore, in the second radical source 190, SiH3 radicals are also selectively generated from F radicals.

[0098] XeF2+ e → Xe * + 2F + e SiH4+ Xe * → SiH3 + Xe + H SiH4+ F → SiH3+ HF

[0099] As explained above, the addition of XeF to SiH4 as a doping gas allows for the efficient generation of SiH3 radicals in the second radical source 190. Therefore, n-type dopants can be efficiently added to the gallium nitride film, improving the controllability of the n-type dopant.

[0100] <Modification 5> As the doping gas supplied from the doping gas supply unit 192, a doping gas in which SiH2Cl2 is added to SiH4 (SiH4 / SiH2Cl2 mixed gas) may also be used. In this case, not only SiH3 radicals but also Cl radicals are generated in the second radical supply source 190. Cl radicals have high electronegativity and can abstract hydrogen from SiH4. Therefore, SiH3 radicals are selectively generated from Cl radicals in the second radical supply source 190. Although SiH2 radicals are also generated, SiH2 radicals have a shorter lifetime than SiH3 radicals and are therefore deactivated by other reactions within the second radical supply source 190. For this reason, the gas supplied from the second radical supply source 190 to the vacuum chamber 100 is mainly SiH3 radicals.

[0101] SiH2Cl2 + e → SiH2 + 2Cl + e SiH4 + Cl → SiH3 + HCl

[0102] As explained above, by adding SiH2Cl2 to SiH4 as a doping gas, SiH3 radicals can be efficiently generated in the second radical source 190. Therefore, n-type dopants can be efficiently added to the gallium nitride film, improving the controllability of the n-type dopant. In addition, Cl radicals may be supplied to the vacuum chamber 100. Cl radicals supplied to the vacuum chamber 100 can etch the amorphous regions of the gallium nitride film on the substrate. This improves the crystallinity of the gallium nitride film.

[0103] <Second Embodiment> Referring to Figures 11 to 13, a gallium nitride film deposition apparatus 20 according to one embodiment of the present invention will be described. In the following, if the configuration of the film deposition apparatus 20 is the same as that of the film deposition apparatus 10, the description of the configuration of the film deposition apparatus 20 may be omitted.

[0104] [1. Configuration of the film deposition apparatus 20] Figure 11 is a schematic diagram showing the configuration of a film deposition apparatus 20 according to one embodiment of the present invention. Using the film deposition apparatus 20, a gallium nitride film mainly containing a p-type dopant can be formed. For convenience, the configuration of the film deposition apparatus 20 will be described below assuming that the p-type dopant of the gallium nitride film is magnesium. However, the p-type dopant is not limited to magnesium.

[0105] As shown in Figure 11, the film deposition apparatus 10 comprises a vacuum chamber 100, a substrate support section 110, a heating section 120, a target 130, a target support section 140, a pump 150, a sputtering power supply 160, a sputtering gas supply section 170, a first radical supply source 180, a dopant supply source 210, and a control unit 200.

[0106] The dopant supply source 210 includes a target and a mechanism such as sputtering or electron beam deposition, and can supply magnesium contained in the target to the vacuum chamber 100. If the dopant supply source 210 includes a sputtering mechanism, a cathode electrode may be provided in the vacuum chamber 100. If the dopant supply source 210 includes a counter-target sputtering mechanism, power is applied between two opposing targets, and magnesium sputtered in a direction approximately horizontal to the targets is supplied to the vacuum chamber 100. If the dopant supply source 210 includes an electron beam deposition mechanism, magnesium evaporated in a direction approximately perpendicular to the target is supplied to the vacuum chamber 100.

[0107] Magnesium from the dopant supply source 210 is supplied to the vacuum chamber 100 through an opening 211 provided in the vacuum chamber 100. To adjust the amount of magnesium supplied to the vacuum chamber 100, a shutter with a variable area of ​​the opening 211 may be provided between the vacuum chamber 100 and the dopant supply source 210. The shutter may be controlled by the control unit 200. This allows magnesium to be supplied to the vacuum chamber 100 while controlling the amount of magnesium. Alternatively, the amount of magnesium can be controlled by adjusting the distance from the target of the dopant supply source 210 to the opening 211.

[0108] [2. Method for forming gallium nitride films] Figure 12 is a flowchart showing a method for depositing a gallium nitride film using a film deposition apparatus 20 according to one embodiment of the present invention. In the gallium nitride film deposition method shown in Figure 12, steps S200 to S290 are executed sequentially.

[0109] Steps S200 to S270 are the same as steps S100 to S170 described in the first embodiment, so the explanation of steps S200 to S270 will be omitted.

[0110] In step S280, the dopant supply source 210 is controlled, and magnesium is supplied from the dopant supply source 210 to the vacuum chamber 100. The magnesium reacts with the gallium nitride film formed on the substrate, and magnesium is added to the gallium nitride film. At this time, no N2 gas or nitrogen radicals are supplied to the vacuum chamber 100. Therefore, magnesium can be efficiently added to the gallium nitride film without reacting with N2 gas or nitrogen radicals.

[0111] By repeating steps S230 to S290, a magnesium-doped gallium nitride film can be formed on the substrate. Here, with reference to Figure 13, the details of the control timing by the control unit 200 will be explained.

[0112] Figure 13 is a sequence diagram showing a method for depositing a gallium nitride film using a film deposition apparatus 20 according to one embodiment of the present invention.

[0113] Figure 13 shows a first period T1 for depositing a gallium nitride film and a second period T2 for adding magnesium to the gallium nitride film. In the film deposition apparatus 20, the first period T1 and the second period T2 are repeated to deposit a gallium nitride film with a p-type dopant.

[0114] During the first period T1, the supply of nitrogen radicals and hydrogen radicals is initiated, followed by the supply of sputtering gas. Subsequently, the sputtering power supply 160 is turned on, and a gallium nitride film is deposited. Also during the first period T1, the sputtering power supply 160 is turned off, and the supply of sputtering gas is stopped. Subsequently, the supply of nitrogen radicals and hydrogen radicals is stopped.

[0115] Since the first period T1 is the same as the first period T1 described in the first embodiment, a detailed explanation of the first period T1 will be omitted.

[0116] During the second period T2, magnesium is supplied to the vacuum chamber 100 from the second radical source 190. At this time, nitrogen radicals are not supplied to the vacuum chamber 100 from the first radical source 180. Therefore, no reaction occurs between magnesium and nitrogen radicals, and the magnesium reacts efficiently with the gallium nitride film on the substrate, allowing magnesium to be added to the gallium nitride film. Subsequently, the supply of magnesium from the dopant source 210 to the vacuum chamber 100 is stopped.

[0117] As described above, in the film deposition apparatus 20, during the first period T1, a gallium nitride film is deposited on the substrate using nitrogen radicals and hydrogen radicals from the first radical supply source 180, and during the second period T2, magnesium is added to the gallium nitride film on the substrate using magnesium from the dopant supply source 210. During the second period T2, since no nitrogen radicals are present in the vacuum chamber 100, magnesium can react efficiently with the gallium nitride film. Therefore, the controllability of p-type dopants in the gallium nitride film is improved in the film deposition apparatus 20.

[0118] Furthermore, the film deposition apparatus 20 can deposit indium gallium nitride by supplying indium from the dopant supply source 210, and can also deposit aluminum gallium nitride by supplying aluminum from the dopant supply source 210.

[0119] <Third Embodiment> Figure 14 is a schematic diagram showing the configuration of a light-emitting element 1000 according to one embodiment of the present invention.

[0120] As shown in Figure 14, the light-emitting element 1000 includes a substrate 1010, a barrier layer 1020, a buffer layer 1030, an undoped semiconductor layer 1035, an n-type semiconductor layer 1040, a light-emitting layer 1050, a p-type semiconductor layer 1060, an n-type electrode 1070, a p-type electrode 1080, and a protective layer 1090. The light-emitting element 1000 is a so-called LED (Light Emitting Diode), but is not limited to this.

[0121] As the substrate 1010, for example, a glass substrate or a quartz substrate can be used. As the barrier layer 1020, for example, a silicon nitride film can be used. As the buffer layer 1030, for example, an aluminum nitride film can be used. As the undoped semiconductor layer 1035, for example, a gallium nitride film can be used. As the n-type semiconductor layer 1040, a silicon-doped gallium nitride film can be used. As the light-emitting layer 1050, a laminate in which indium gallium nitride films and gallium nitride films are alternately stacked can be used. As the p-type semiconductor layer 1060, a magnesium-doped gallium nitride film can be used. As the n-type electrode 1070, a multilayer metal film such as titanium / aluminum / titanium / gold (Ti / Al / Ti / Au) or chromium / nickel / gold (Cr / Ni / Au), or a transparent conductive film such as indium tin oxide (ITO) can be used. As the p-type electrode 1080, a multilayer metal film such as palladium / gold (Pd / Au) or nickel / gold (Ni / Au), or a transparent conductive film such as indium tin oxide (ITO) can be used. As the protective layer 1090, a silicon oxide film or the like can be used. In addition, in the light-emitting element 1000 according to this embodiment, a configuration without a barrier layer 1020 can also be applied.

[0122] Figure 15 is a flowchart showing a method for manufacturing a light-emitting element 1000 according to one embodiment of the present invention.

[0123] In step S1000, a silicon nitride film is deposited on the substrate 1010 as a barrier layer 1020. The silicon nitride film can be deposited using a CVD apparatus.

[0124] In step S1010, an aluminum nitride film is formed as a buffer layer 1030 on the barrier layer 1020. The aluminum nitride film can be formed by sputtering aluminum nitride onto the target 130 in the film forming apparatus 10 or the film forming apparatus 20. At this time, nitrogen radicals and hydrogen radicals may be supplied from the first radical supply source 180.

[0125] In step S1020, a gallium nitride film is formed as an undoped semiconductor layer 1035 on the buffer layer 1030. The gallium nitride film can be formed using the film forming apparatus 10 described in the first embodiment.

[0126] In step S1030, a gallium nitride film added with silicon is formed as an n-type semiconductor layer 1040 on the undoped semiconductor layer 1035. The gallium nitride film added with silicon can be formed using the film forming apparatus 10 described in the first embodiment.

[0127] In step S1040, an indium gallium nitride film and a gallium nitride film are alternately formed as a light emitting layer 1050 on the n-type semiconductor layer 1040. The indium gallium nitride film can be formed in the film forming apparatus 20 by supplying indium from the dopant supply source 210 using gallium nitride for the target 130. That is, the indium gallium nitride film can be formed by providing an indium target in the dopant supply source 210 of the film forming apparatus 20 described in the second embodiment. Further, the gallium nitride film can be formed by supplying nitrogen radicals and hydrogen radicals from the first radical supply source 180 using gallium nitride for the target 130 of the film forming apparatus 20. At this time, the oxygen concentration of the light emitting layer 1050 is preferably less than 1×10 18 cm -3 It is preferable that it is less than. In the film forming apparatus 20, since the concentration of residual oxygen in the vacuum chamber 100 can be reduced, the oxygen concentration of the light emitting layer 1050 can be made within the above range.

[0128] In step S1050, a magnesium-doped gallium nitride film is deposited on the light-emitting layer 1050 as a p-type semiconductor layer 1060. The magnesium-doped gallium nitride film can be deposited using the deposition apparatus 20 described in the second embodiment. At this time, the oxygen concentration of the p-type semiconductor layer 1060 is 1 × 10⁻⁶. 18 cm -3 It is preferable that the value be less than the specified value. In the film deposition apparatus 20, the concentration of residual oxygen in the vacuum chamber 100 can be reduced, so that the oxygen concentration of the light-emitting layer 1050 can be kept within the above range.

[0129] In step S1060, heat treatment is performed. In some cases, the activation rate of magnesium added to the gallium nitride film in step S1050 may be low. In such cases, heat treatment can be performed to activate the magnesium and enable it to function as a p-type semiconductor layer 1060.

[0130] In step S1070, the p-type semiconductor layer 1060, the light-emitting layer 1050, and the n-type semiconductor layer 1040 are etched into a predetermined pattern using photolithography. The n-type semiconductor layer 1040 is etched in such a way that its surface is exposed (i.e., a portion of the n-type semiconductor layer 1040 remains). For etching, for example, plasma etching can be used.

[0131] In step S1080, a transparent conductive film of ITO is formed on the n-type semiconductor layer 1040 as an n-type electrode 1070.

[0132] In step S1090, a Pd / Au metal film is formed on the p-type semiconductor layer 1060 as a p-type electrode 1080.

[0133] In step S1100, heat treatment is performed. This reduces the contact resistance between the n-type semiconductor layer 1040 and the n-type electrode 1070, and between the p-type semiconductor layer 1060 and the p-type electrode 1080.

[0134] A protective layer 1090 is formed on the top surface and side walls of the light-emitting element 1000. The protective layer 1090 may be formed after step S1070 or after step S1090. An opening is formed in the protective layer 1090, which can be formed using photolithography and etching.

[0135] As described above, in the fabrication of the light-emitting element 1000 according to this embodiment, steps S1010 to S1050 can be performed using the film deposition apparatus 10 and the film deposition apparatus 20. Therefore, the light-emitting element 1000 can be fabricated using a substrate with low heat resistance, such as a glass substrate, and a light-emitting element 1000 in which the dopants of the n-type semiconductor layer 1040 and the p-type semiconductor layer are controlled can be fabricated.

[0136] <Fourth Embodiment> Figure 16 is a schematic diagram showing the configuration of a semiconductor device 2000 according to one embodiment of the present invention.

[0137] As shown in Figure 16, the semiconductor device 2000 includes a substrate 2010, a barrier layer 2020, a buffer layer 2030, a gallium nitride layer 2040, a first aluminum gallium nitride layer 2050, a second aluminum gallium nitride layer 2060, a third aluminum gallium nitride layer 2070, a source electrode 2080, a drain electrode 2090, a gate electrode 2100, a first insulating layer 2110, a second insulating layer 2120, and a shield electrode 2130. The semiconductor device 2000 is a so-called HEMT (High Electron Mobility Transistor), but is not limited to this.

[0138] As the substrate 2010, for example, a glass substrate or a quartz substrate can be used. As the barrier layer 2020, for example, a silicon nitride film can be used. As the buffer layer 2030, for example, an aluminum nitride film can be used. As the gallium nitride layer 2040, a gallium nitride film can be used. As the first aluminum gallium nitride layer 2050, an aluminum gallium nitride film can be used. As the second aluminum gallium nitride layer 2060, for example, a silicon-doped gallium nitride film can be used. As the third aluminum gallium nitride layer 2070, an aluminum gallium nitride film can be used. As the source electrode 2080 and drain electrode 2090, for example, a multilayer metal film such as titanium / aluminum (Ti / Al) can be used. As the gate electrode 2100, for example, a multilayer metal film such as nickel / gold (Ni / Au) can be used. As the first insulating layer 2110, for example, a silicon nitride film can be used. As the second insulating layer 2120, for example, a silicon oxide film can be used. For example, a multilayer metal film such as titanium / aluminum (Ti / Al) can be used as the shield electrode 2130. Furthermore, in the semiconductor element 2000 according to this embodiment, a configuration without the barrier layer 1020 can also be applied.

[0139] Figure 17 is a flowchart showing a method for manufacturing a semiconductor device 2000 according to one embodiment of the present invention.

[0140] In step S2000, a silicon nitride film is deposited on the substrate 2010 as a barrier layer 2020.

[0141] In step S2010, an aluminum nitride film is deposited on the barrier layer 2020 as a buffer layer 2030.

[0142] In step S2020, a gallium nitride film is deposited on the buffer layer 2030 as a gallium nitride layer 2040. The gallium nitride film can be deposited in the deposition apparatus 10 or 20 by using gallium nitride as the target 130 and supplying nitrogen radicals and hydrogen radicals from the first radical supply source 180.

[0143] In step S2030, an aluminum gallium nitride film is deposited on the gallium nitride layer 2040 as the first aluminum gallium nitride layer 2050. The aluminum gallium nitride film can be deposited in the deposition apparatus 20 by using gallium nitride as the target 130 and supplying aluminum from the dopant supply source 210. That is, the aluminum gallium nitride film can be deposited by providing an aluminum target in the dopant supply source 210 of the deposition apparatus 20 described in the second embodiment.

[0144] In step S2040, a silicon-doped aluminum gallium nitride film is deposited on the first aluminum gallium nitride layer 2050 as a second aluminum gallium nitride layer 2060. The silicon-doped aluminum gallium nitride film can be deposited using the film deposition apparatus 10 described in the first embodiment. In the aluminum gallium nitride film, aluminum gallium nitride is used as the target 130 of the film deposition apparatus 10.

[0145] Furthermore, the aluminum gallium nitride film can also be deposited using a film deposition apparatus in which the film deposition apparatus 10 and film deposition apparatus 20 are integrated (a film deposition apparatus in which the vacuum chamber 100 is shared). In this case, gallium nitride is used as the target 130, SiH3 radicals are supplied from the second radical supply source 190, and aluminum is supplied from the dopant supply source 210.

[0146] In step S2050, a gallium aluminum nitride film is deposited on the second gallium aluminum nitride layer 2060 as a third gallium aluminum nitride layer 2070. The gallium aluminum nitride film can be deposited in the deposition apparatus 20 by using gallium nitride as the target 130 and supplying aluminum from the dopant supply source 210. In other words, the gallium aluminum nitride film can be deposited by providing an aluminum target in the dopant supply source 210 of the deposition apparatus 20 described in the second embodiment.

[0147] In step S2060, the third aluminum gallium nitride layer 2070 and the second aluminum gallium nitride layer 2060 are etched into a predetermined pattern using photolithography. The second aluminum gallium nitride layer 2060 is etched in such a way that its surface is exposed (i.e., a portion of the second aluminum gallium nitride layer 2060 remains). For etching, for example, plasma etching can be used.

[0148] In step S2070, a Ni / Au metal film is formed as the gate electrode 2100.

[0149] In step S2080, a Ti / Al metal film is formed as the source electrode 2080 and the drain electrode 2090.

[0150] In step S2090, a silicon nitride film is deposited as the first insulating layer 2110 so as to cover the source electrode 2080, the drain electrode 2090, and the gate electrode 2100. The silicon nitride film can be deposited using a CVD apparatus.

[0151] In step S2100, a silicon oxide film is formed as a second insulating layer 2120 so as to cover the first insulating layer 2110. The silicon oxide film can be formed using a CVD apparatus.

[0152] In step S2110, a Ti / Al metal film is formed on the second insulating layer 2120 as a shielding electrode.

[0153] As described above, in the fabrication of the semiconductor device 2000 according to this embodiment, steps S2020 to S2050 can be performed using the film deposition apparatus 10 and the film deposition apparatus 20. Therefore, the semiconductor device 2000 can be fabricated using a substrate with low heat resistance, such as a glass substrate. A semiconductor device 2000 in which the dopant of the second aluminum gallium nitride layer 2060 is controlled can be fabricated.

[0154] The embodiments described above as examples of the present invention can be combined and implemented as appropriate, insofar as they do not contradict each other. Furthermore, any modifications made by those skilled in the art to each embodiment, such as adding, deleting, or changing components, or adding, omitting, or changing processes, are also included within the scope of the present invention, as long as they retain the essence of the present invention.

[0155] Any effects or benefits other than those brought about by the embodiments described above, if they are clear from the description herein or easily predictable to a person skilled in the art, are naturally considered to be brought about by the present invention. [Explanation of Symbols]

[0156] 10, 10A, 20: Film deposition apparatus, 100: Vacuum chamber, 110: Substrate support section, 120: Heating section, 130: Target, 140: Target support section, 150: Pump, 151: Piping, 152: Valve, 160: Sputtering power supply, 161: Wiring, 170: Sputtering gas supply section, 171: Piping, 172: Mass flow controller, 180: First radical supply source, 181: Piping, 182: Nitrogen gas supply section, 183: Hydrogen gas supply section, 184: Piping, 185: Piping, 186: First plasma power supply, 190: Second radical supply source, 191: Piping, 192: Doping gas supply section, 193: Piping, 194: Second plasma power supply, 195A: Piping, 200: Control unit, 210: Dopant supply source, 211: Aperture, 1000: Light-emitting element, 1010: Substrate, 1020: Barrier layer, 1030: Buffer layer, 1035: Undoped semiconductor layer, 1040: n-type semiconductor layer, 1050: Light-emitting layer, 1060: p-type semiconductor layer, 1070: n-type electrode, 1080: p-type electrode, 1090: Protective layer, 2000: Semiconductor element, 2010: Substrate, 2020: Barrier layer, 2030: Buffer layer, 2040: Gallium nitride layer, 2050: First aluminum gallium nitride layer, 2060: Second aluminum gallium nitride layer, 2070: Third aluminum gallium nitride layer, 2080: Source electrode, 2090: Drain electrode, 2100: Gate electrode, 2110: First insulating layer, 2120: Second insulating layer, 2130: Shield electrode

Claims

1. A vacuum chamber capable of creating a vacuum inside, A substrate support portion is provided within the vacuum chamber to support the substrate, A target support section provided within the vacuum chamber, which supports a target containing nitrogen and gallium, A sputtering gas supply unit connected to the vacuum chamber and supplying sputtering gas to the vacuum chamber, A sputtering power supply for applying voltage to the target, Connected to the aforementioned vacuum chamber, N ２ Nitrogen radicals and H generated from the gas ２ A first radical source capable of supplying at least one hydrogen radical generated from a gas to the vacuum chamber, Connected to the aforementioned vacuum chamber, SiH ３ A second radical source capable of supplying radicals to the vacuum chamber, A film deposition apparatus comprising a sputtering gas supply unit, a sputtering power supply, a first radical supply source, and a control unit for controlling the second radical supply source.

2. The aforementioned N ２ gas and the H ２ The film deposition apparatus according to claim 1, wherein the gas is supplied to the first radical supply source via separate piping.

3. The control unit has a first period during which it supplies the sputtering gas, the nitrogen radicals, and the hydrogen radicals to the vacuum chamber, and the SiH ３ The film deposition apparatus according to claim 1, wherein the sputtering gas supply unit, the sputtering power supply, the first radical supply source, and the second radical supply source are controlled so as to repeat a second period of supplying radicals to the vacuum chamber.

4. The film deposition apparatus according to claim 3, wherein, during the first period, the control unit controls the supply of the sputtering gas to turn on the sputtering power supply after the supply of the nitrogen radicals and the hydrogen radicals has been started.

5. The film deposition apparatus according to claim 4, wherein, during the first period, the control unit controls the supply of the sputtering gas to turn off the sputtering power supply, and then stops the supply of the nitrogen radicals and the hydrogen radicals.

6. The film deposition apparatus according to claim 3, wherein during the second period, the control unit controls the sputtering power supply to be turned on.

7. The film deposition apparatus according to claim 6, wherein the first power of the sputtering power supply during the first period is greater than the second power of the sputtering power supply during the second period.

8. The second radical source is SiH ４ A film deposition apparatus according to claim 1, wherein gas is supplied.

9. The second radical source further includes XeF ２ gas or SiH ２ Cl ２ gas is supplied, and the film forming apparatus according to claim 8.

10. The film deposition apparatus according to claim 3, wherein the second period is shorter than the first period.

11. A vacuum chamber capable of creating a vacuum inside, A substrate support portion is provided within the vacuum chamber to support the substrate, A target support section provided within the vacuum chamber, which supports a target containing nitrogen and gallium, A sputtering gas supply unit connected to the vacuum chamber and supplying sputtering gas to the vacuum chamber, A sputtering power supply for applying voltage to the target, Connected to the aforementioned vacuum chamber, N ２ Nitrogen radicals and H generated from the gas ２ A radical source capable of supplying at least one hydrogen radical generated from a gas to the vacuum chamber, A dopant supply source connected to the vacuum chamber and capable of supplying dopants to the vacuum chamber, The system includes a control unit that controls the sputtering gas supply unit, the sputtering power supply, the radical supply source, and the dopant supply source, The control unit supplies the sputtering gas, the nitrogen radicals, and the hydrogen radicals to the vacuum chamber and controls the sputtering gas supply unit, the sputtering power supply, the radical supply source, and the dopant supply source so that a first period in which the sputtering power supply is ON and a second period in which the dopant is supplied to the vacuum chamber are repeated. A film deposition apparatus in which, during the first period, the control unit controls the supply of the sputtering gas to turn on the sputtering power supply after the supply of the nitrogen radicals and the hydrogen radicals has been started.

12. The film deposition apparatus according to claim 11, wherein during the first period, the control unit controls the supply of the sputtering gas to turn off the sputtering power supply, and then stops the supply of the nitrogen radicals and the hydrogen radicals.

13. The film deposition apparatus according to claim 11, wherein the dopant comprises one of magnesium, indium, and aluminum.

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