Sputtering device and sputtering method

Abstract

A sputtering device according to the present invention has a substrate holding part that holds a substrate, a first target that is provided so as to be opposite the substrate holding part, a second target that is aligned with the first target so as to be opposite the substrate holding part, and a partition wall that is provided between the first target and the second target. A first normal line at an arbitrary position on the first target and a second normal line at an arbitrary position on the second target are each connected to an arbitrary point on the substrate.

Description

Sputtering apparatus and sputtering method

[0001] An embodiment of the present invention relates to a sputtering apparatus and a sputtering method, and more particularly to a sputtering apparatus and a sputtering method using a rotary target.

[0002] For small and medium-sized display devices such as smartphones, display devices using liquid crystal or OLED (organic light-emitting diode) have already been commercialized. Among these, OLED display devices using OLED, which is a self-emissive element, have the advantage of high contrast and no need for backlight compared to liquid crystal display devices. However, because OLED is composed of organic compounds, it is difficult to ensure high reliability of OLED display devices due to degradation of the organic compounds.

[0003] In recent years, development of so-called micro LED or mini LED displays, in which tiny LED chips are mounted within the pixels of a circuit board, has been progressing as next-generation display devices. LEDs are self-emitting elements similar to OLEDs. However, unlike OLEDs, LEDs are composed of stable inorganic compounds containing gallium (Ga) or indium (In). Therefore, compared to OLED display devices, micro LED display devices are more likely to ensure high reliability. Furthermore, LED chips have high luminous efficiency and can achieve high brightness. Therefore, micro LED display devices or mini LED display devices are expected to be next-generation display devices with high reliability, high brightness, and high contrast.

[0004] Gallium nitride films used in micro LEDs and the like are generally formed on sapphire substrates using metal organic chemical vapor deposition (MOCVD) or hydride vapor phase epitaxy (HVPE) at high temperatures of 800° C. to 1000° C. However, in recent years, a method for forming a gallium nitride film by sputtering has been developed, which allows film formation at relatively low temperatures (see, for example, Patent Document 1).

[0005] JP 2012-119569 A

[0006] If the films that make up gallium nitride micro-LEDs can be deposited at low temperatures, it will be possible to form micro-LEDs directly on glass substrates. Micro-LEDs are formed by stacking multiple films with different compositions. Conventional sputtering equipment requires a separate target and chamber for each film with a different composition.

[0007] In view of the above problems, one object of one embodiment of the present invention is to provide a new sputtering apparatus and sputtering method.

[0008] A sputtering apparatus according to one embodiment of the present invention includes a substrate holder for holding a substrate, a first target arranged to face the substrate holder, a second target arranged alongside the first target to face the substrate holder, and a partition wall arranged between the first target and the second target, wherein a first normal at an arbitrary position of the first target and a second normal at an arbitrary position of the second target are each connected to an arbitrary point on the substrate.

[0009] A sputtering apparatus according to one embodiment of the present invention includes a substrate holder configured to hold a substrate, a first target disposed opposite the substrate holder and having a first target member attached thereto, and a second target disposed parallel to the first target and facing the substrate holder and having a second target member different from the first target member attached thereto. The first target member contains gallium.

[0010] A sputtering method according to one embodiment of the present invention includes holding a substrate on a substrate holding part facing a first target and a second target, and in a first step, generating plasma for the first target while moving the first target and the substrate holding part relative to each other to deposit a film of a first material of the first target on the substrate, and in a second step, generating plasma for the second target while moving the second target and the substrate holding part relative to each other to deposit a film of a second material of the second target on the substrate, thereby forming a layered structure including the first material and the second material.

[0011] FIG. 1 is a diagram illustrating an overview of a sputtering apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a sputtering method according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a sputtering method according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a sputtering method according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing a semiconductor device manufactured using the sputtering method according to an embodiment of the present invention. FIG. 6 is a flowchart illustrating a modified example of the sputtering method according to an embodiment of the present invention. FIG. 7 is a diagram illustrating a modified example of the sputtering method according to an embodiment of the present invention. FIG. 8 is a diagram illustrating a modified example of the sputtering apparatus according to an embodiment of the present invention. FIG. 9 is a diagram illustrating a sputtering method according to an embodiment of the present invention. FIG. 10 is a diagram illustrating a modified example of the sputtering method according to an embodiment of the present invention. FIG. 11 is a diagram illustrating a sputtering apparatus according to an embodiment of the present invention. FIG. 12 is a diagram illustrating a modified example of the sputtering method according to an embodiment of the present invention. FIG. 13 is a diagram illustrating a sputtering apparatus according to an embodiment of the present invention. FIG. 14 is a diagram illustrating a modified example of the sputtering method according to an embodiment of the present invention. FIG. 15 is a diagram illustrating a sputtering apparatus according to an embodiment of the present invention. FIG. 16 is a diagram illustrating a modified example of the sputtering method according to an embodiment of the present invention.

[0012] Each embodiment of the present invention will be described below with reference to the drawings. The following disclosure is merely an example. Configurations that a person skilled in the art can easily arrive at by appropriately modifying the configuration of the embodiment while maintaining the gist of the invention are naturally included within the scope of the present invention. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment. However, the illustrated shapes are merely examples and do not limit the interpretation of the present invention. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0013] In each embodiment of the present invention, the direction from the first member to the second member is referred to as "up" or "upper." Conversely, the direction from the second member to the first member is referred to as "down" or "downward." For convenience of explanation, the terms "up" and "downward" are used in the description. However, for example, the vertical relationship between the first member and the second member may be reversed from that illustrated. In the following description, for example, the expression "second member above the first member" merely describes the vertical relationship between the first member and the second member as described above, and other members may be disposed between the first member and the second member. "Above" or "below" refers to the stacking order in a structure in which multiple layers are stacked. When referring to a second member above a first member, the first member and the second member may not overlap in a planar view. On the other hand, when referring to a second member vertically above a first member, the first member and the second member may overlap in a planar view.

[0014] In this specification, the terms "film" and "layer" may be used interchangeably in some cases.

[0015] In this specification, unless otherwise specified, expressions such as "α includes A, B, or C," "α includes any 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 to C. Furthermore, these expressions do not exclude cases where α includes other elements.

[0016] The following embodiments can be combined with each other as long as no technical contradiction occurs.

[0017] 1 to 4, a sputtering apparatus 10 according to one embodiment of the present invention, a sputtering method using the sputtering apparatus 10, and a semiconductor device 20 formed by the sputtering method will be described.

[0018] [1-1. Configuration of Sputtering Apparatus 10] FIG. 1 is a diagram illustrating an overview of a sputtering apparatus according to one embodiment of the present invention. FIG. 1 is a top view of the sputtering apparatus 10. As shown in FIG. 1, the sputtering apparatus 10 includes a chamber 100, a target unit 200, and a substrate holder 300. FIG. 1 illustrates a portion of the chamber 100. The chamber 100 forms a closed space. Although not shown, the chamber 100 is provided with an exhaust port and a process gas supply port. The chamber 100 can be depressurized through the exhaust port. Gases such as argon and nitrogen required for sputtering can be supplied into the chamber 100 through the process gas supply port. A substrate 310, which is an object to be deposited, is held by the substrate holder 300. In the example of FIG. 1, the substrate 310 is held by the substrate holder 300 so that the main surface of the substrate 310 extends in the X-axis and Z-axis directions. In other words, the substrate 310 is held vertically by the substrate holder 300.

[0019] The target unit 200 includes rotary targets RT1 and RT2 arranged side by side to face the substrate holding unit 300. The rotary targets RT1 and RT2 each include support members 210 and 220, fixing members 211 and 221, yokes 212 and 222, central magnets 213 and 223, peripheral magnets 214 and 224, backing tubes 215 and 225, and targets 216 and 226. The rotary targets RT1 and RT2 are surrounded by shielding plates 217 and 227. Each of the above components constituting the rotary targets RT1 and RT2 has a shape extending in the Z direction. The rotary targets RT1 and RT2 are arranged spaced apart in the X direction. The rotary target RT1 may be referred to as the "first target." The rotary target RT2 may be referred to as the "second target."

[0020] The support members 210, 220 are rotatably fixed to the chamber 100. The fixed members 211, 221 are connected to the support members 210, 220 and extend from the support members 210, 220 toward the backing tubes 215, 225. Yokes 212, 222 are fixed to the ends of the fixed members 211, 221. The central magnets 213, 223 and peripheral magnets 214, 224 are fixed to the yokes 212, 222 and extend from the yokes 212, 222 toward the backing tubes 215, 225. The ends of the central magnets 213, 223 and peripheral magnets 214, 224 on the backing tube 215, 225 side have curved shapes that follow the inner walls of the backing tubes 215, 225.

[0021] The central magnets 213, 223 and the peripheral magnets 214, 224 have a linear shape extending in the Z direction. The central magnets 213, 223 and the peripheral magnets 214, 224 rotate along the inner walls of the backing tubes 215, 225 around the support members 210, 220. The support members 210, 220 are fixed to fixing members 211, 221 and rotate together with the central magnets 213, 223 and the peripheral magnets 214, 224. However, the support members 210, 220 may be fixed without rotating relative to the chamber 100. In this case, the fixing members 211, 221 are rotatably connected to the support members 210, 220.

[0022] The targets 216, 226 are fixed to the backing tubes 215, 225. The backing tubes 215, 225 and the targets 216, 226 have a cylindrical shape centered on an axis extending in the Z direction, and rotate around the support members 210, 220. The targets 216, 226 rotate independently of the central magnets 213, 223 and the peripheral magnets 214, 224. In the following description, when there is no particular distinction between the central magnet 213 and the peripheral magnet 214, and when there is no particular distinction between the central magnet 223 and the peripheral magnet 224, these may be simply referred to as "magnets."

[0023] 1, the position of the magnet at which film formation is possible on the substrate 310 may be referred to as the "film formation position." In other words, when the magnet is positioned at the film formation position, the plasma region PLS generated on the rotary targets RT1 and RT2 spreads outside the shielding plates 217 and 227 via slits 218 and 228, which will be described later. On the other hand, the position of the magnet at which film formation is not possible on the substrate 310 may be referred to as the "non-film formation position." In other words, when the magnet is positioned at the non-film formation position, the plasma region PLS generated on the rotary targets RT1 and RT2 is shielded by the shielding plates 217 and 227 and does not spread outside thereof.

[0024] Gallium, gallium nitride, aluminum, aluminum nitride, indium, indium nitride, silicon, and silicon nitride are used as the targets 216, 226. Materials obtained by doping the above materials with impurities (dopants) may also be used as the targets 216, 226. For example, materials obtained by doping gallium nitride with magnesium or silicon may also be used. Gallium nitride containing magnesium as a dopant functions as a P-type semiconductor. Gallium nitride containing silicon as a dopant functions as an N-type semiconductor.

[0025] The target 216 and the target 226 are made of different materials. For example, gallium nitride is used as the target 216, and aluminum nitride is used as the target 226. Alternatively, gallium nitride is used as the target 216, and indium nitride is used as the target 226. Alternatively, intrinsic gallium nitride is used as the target 216, and gallium nitride into which a dopant has been introduced is used as the target 226. "Intrinsic" means that no dopant has been intentionally introduced.

[0026] The central magnets 213, 223 have a polarity different from that of the peripheral magnets 214, 224. In other words, these magnets form a magnetic field that flows from the central magnets 213, 223 toward the peripheral magnets 214, 224 (or vice versa). This magnetic field confines electrons in the plasma, forming a high-concentration plasma region PLS in the region corresponding to the central magnets 213, 223 and the peripheral magnets 214, 224. In the plasma region PLS, argon introduced as a process gas is ionized. The ionized argon is accelerated toward the targets 216, 226 in sheath regions formed between the plasma region PLS and the target 216 and between the plasma region PLS and the target 226. The accelerated argon collides with the targets 216, 226, sputtering the target material.

[0027] As described above, the sputtered target material flies from the surfaces of the targets 216, 226 toward the plasma region PLS. In FIG. 1 , the dotted lines that extend from the surfaces of the targets 216, 226 through the plasma region PLS to the substrate 310 represent the trajectories of the sputtered target material. By the sputtering described above, the target material is deposited on the substrate 310, centered at the position where the dotted lines reach the substrate 310. The centers of the support members 210, 220 are located on extensions of the dotted lines. In other words, the dotted lines are normals to any surface of the targets 216, 226. The dotted line extending from the target 216 toward the substrate 310 may be referred to as a "first normal." The dotted line extending from the target 226 toward the substrate 310 may be referred to as a "second normal." Each of the first normal and the second normal is connected to any point on the substrate 310. In other words, the targets 216 , 226 are positioned so that the target material sputtered from them is deposited at the same point on the substrate 310 .

[0028] The shielding plates 217 and 227 are provided with slits 218 and 228. The shielding plates 217 and 227 continuously surround the peripheries of the targets 216 and 226 except for the areas where the slits 218 and 228 are provided. The slit 218 is provided on the rotary target RT2 side of a line passing through the rotation axis of the rotary target RT1 among lines perpendicular to the surface of the substrate holding unit 300 or the substrate 310. The slit 228 is provided on the rotary target RT1 side of a line passing through the rotation axis of the rotary target RT2 among lines perpendicular to the surface of the substrate holding unit 300 or the substrate 310.

[0029] The portions of the shielding plates 217, 227 sandwiched between the rotary targets RT1 and RT2 function as partition walls that prevent the target material sputtered from the rotary target RT1 from depositing on the rotary target RT2, and also function as partition walls that prevent the target material sputtered from the rotary target RT2 from depositing on the rotary target RT1. The portions that function as partition walls are provided so as to shield the space sandwiched between the rotary targets RT1 and RT2.

[0030] The portion of the shielding plate 217 located between the rotary target RT1 and the substrate holding unit 300 (or the substrate 310) prevents the target material sputtered from the rotary target RT1 from passing through areas other than the slit 218 and depositing on the substrate 310. This portion may be referred to as the "first shielding plate." The portion of the shielding plate 227 located between the rotary target RT2 and the substrate holding unit 300 (or the substrate 310) prevents the target material sputtered from the rotary target RT2 from passing through areas other than the slit 228 and depositing on the substrate 310. This portion may be referred to as the "second shielding plate."

[0031] When expressed as above, the first shielding plate corresponds to a portion of shielding plate 217 that extends parallel to the surface of substrate holding unit 300. The second shielding plate corresponds to a portion of shielding plate 227 that extends parallel to the surface of substrate holding unit 300. The partition corresponds to one or both of the portions of shielding plates 217, 227 that extend in the same direction as a perpendicular to the surface of substrate holding unit 300 or substrate 310 between rotary targets RT1 and RT2. In this case, it can be said that the first shielding plate and the second shielding plate are connected to the partition.

[0032] The substrate holding unit 300 is moved in the direction of the arrow by a moving mechanism 320. As the moving mechanism 320, for example, a roller that contacts the substrate holding unit 300 is provided. However, the moving mechanism 320 is not limited to the configuration shown in FIG. 1 as long as it can move the substrate holding unit 300 in the direction of the arrow while holding the substrate 310. In this embodiment, a configuration in which the substrate holding unit 300 moves relative to the target unit 200 is illustrated, but the configuration is not limited to this. For example, the position of the substrate holding unit 300 may be fixed, and the target unit 200 may move relative to the substrate holding unit 300. In other words, the substrate holding unit 300 can move relative to the target unit 200.

[0033] [1-2. Sputtering method using sputtering apparatus 10] Fig. 2 is a flow chart showing a sputtering method according to one embodiment of the present invention. Figs. 3A and 3B are diagrams explaining a sputtering method according to one embodiment of the present invention. The sputtering method using the sputtering apparatus 10 will be explained using these drawings. The chamber 100 is omitted in Figs. 3A and 3B.

[0034] First, a substrate 310 is introduced into the chamber and held by the substrate holder 300 (step S301: Holding the substrate on the substrate support). Next, the chamber is depressurized by evacuation using a vacuum pump or the like, and a process gas is introduced into the chamber (step S302: Introducing the process gas). After the process gas is introduced, power is supplied to the rotary target RT1, and plasma is generated at the rotary target RT1, as shown in FIG. 3A (step S303: Plasma ON for the first RT). At this time, power is not supplied to the rotary target RT2, so no plasma is generated at the rotary target RT2 (step S303: Plasma OFF for the second RT). In this state, the substrate holder 300 holding the substrate 310 is moved in the direction of the arrow, as shown in FIG. 3A (step S304: Moving the substrate). In step S304, a film of the material (first material) of the target 216 attached to the rotary target RT1 is formed on the substrate 310.

[0035] 3A, and when film formation is completed up to the edge of the film formation region of the substrate 310, the substrate holding unit 300 moves in the opposite direction of the arrow. During the reverse movement, the film formation may be continued, or the plasma may be stopped so that film formation is not performed.

[0036] Once the above-described reverse movement is complete, power is supplied to both rotary targets RT1 and RT2, and plasma is generated at the rotary targets RT1 and RT2 as shown in FIG. 3B (step S305; plasma ON for the first RT, plasma ON for the second RT). In this state, the substrate holder 300 holding the substrate 310 is moved in the direction indicated by the arrow (step S306; substrate movement). Through steps S305 and S306, the material of the target 216 and the material of the target 226 (second material) attached to the rotary targets RT1 and RT2 are deposited on the substrate 310. As a result, a film of a compound composed of the materials of the targets 216 and 226 is deposited on the substrate 310.

[0037] The power supply to the rotary targets RT1 and RT2 is stopped, the plasma generated thereon is stopped (step S307; plasma OFF to the first RT, plasma OFF to the second RT), and the supply of process gas is stopped, thereby completing the above film formation process.

[0038] In the above sputtering method, a configuration has been exemplified in which plasma is generated for both rotary targets RT1 and RT2 in step S305, and films of the materials of the targets 216 and 226 are formed on the substrate 310. However, the present invention is not limited to this configuration. For example, a film of only the material of the target 226 may be formed on the substrate 310 by generating plasma only for the rotary target RT2, without generating plasma for the rotary target RT1.

[0039] 4 is a cross-sectional view showing a semiconductor device manufactured using a sputtering method according to one embodiment of the present invention. When gallium nitride is used as target 216 and aluminum nitride is used as target 226, the above-described film formation process can be performed to manufacture a semiconductor device 20 as shown in FIG.

[0040] With the above configuration, when the film formation shown in steps S303 and S304 of Fig. 2 and Fig. 3A is performed, a gallium nitride layer (GaN layer) is formed on the substrate 310. Subsequently, when the film formation shown in steps S305 and S306 of Fig. 2 and Fig. 3B is performed, a gallium nitride layer (aluminum gallium nitride layer; AlGaN layer) doped with aluminum as a dopant is formed on the substrate 310. As a result of the above film formation, a stack of AlGaN layer / GaN layer is formed on the substrate 310. In other words, the gallium nitride layer and the aluminum gallium nitride layer can be formed consecutively in the same chamber.

[0041] An example of a semiconductor device formed using the above-described film formation process is the semiconductor device 20 shown in Fig. 4. As shown in Fig. 4, the semiconductor device 20 is formed on a substrate 310. The semiconductor device 20 has a first gallium nitride layer 330, a second gallium nitride layer 340, a gate insulating layer 350, a gate electrode 360, a source electrode 370, and a drain electrode 380.

[0042] An intrinsic GaN layer is formed as the first gallium nitride layer 330. An AlGaN layer is formed as the second gallium nitride layer 340. The first gallium nitride layer 330 functions as a channel of the semiconductor device 20. Aluminum oxide is formed as the gate insulating layer 350. Common metal materials such as aluminum, titanium, and molybdenum are formed as the gate electrode 360, source electrode 370, and drain electrode 380.

[0043] By using the sputtering apparatus 10 and film formation process described above, layers of different compositions can be deposited in the same chamber to form a stacked structure. For example, an AlGaN layer and a GaN layer can be deposited consecutively in the same chamber 100 as the second gallium nitride layer 340 and the first gallium nitride layer 330. This prevents dust and contaminants from adhering to the interface between the first gallium nitride layer 330 and the second gallium nitride layer 340 (the interface between the AlGaN layer and the GaN layer). As a result, the interface between the AlGaN layer and the GaN layer can be kept clean, thereby achieving a semiconductor device 20 with high mobility and high reliability.

[0044] [1-4. Variation 1 of the sputtering method] Fig. 5 is a flow chart showing a variation of the sputtering method according to one embodiment of the present invention. Figs. 6A and 6B are diagrams explaining a variation of the sputtering method according to one embodiment of the present invention. Using these drawings, a variation of the sputtering method using the sputtering apparatus 10 will be explained. In Figs. 6A and 6B, the chamber 100 is omitted.

[0045] 5, steps S501 and S502 are the same as steps S201 and S202 in FIG. 2, and therefore will not be described. After the process gas is introduced in step S502, as shown in FIG. 6A, the positions of the magnets (central magnet 213 and peripheral magnet 214) of the rotary target RT1 are controlled to the film-forming position (step S503; the magnets of the first RT are controlled to the film-forming position), and the positions of the magnets (central magnet 223 and peripheral magnet 224) of the rotary target RT2 are controlled to the non-film-forming position (step S503; the magnets of the second RT are controlled to the non-film-forming position). In this state, power is supplied to the rotary targets RT1 and RT2, and plasma is generated for both of them (step S504; plasma is turned on for the first RT and plasma is turned on for the second RT).

[0046] Through the above steps, plasma is generated for both rotary targets RT1 and RT2, as shown in FIG. 6A , but only the target material sputtered from target 216 forms a film on substrate 310. The target material sputtered from target 226 flows in the opposite direction from substrate 310 and is blocked by shielding plate 227, preventing the target material from forming a film on substrate 310. In other words, plasma is generated at the position where slit 218 is provided by controlling the magnet included in rotary target RT1, and plasma is generated at the position where slit 228 is not provided by controlling the magnet included in rotary target RT2. In this state, substrate holder 300 holding substrate 310 moves in the direction of the arrow (step S505: substrate movement). Through step S505, only the material of target 216 attached to rotary target RT1 forms a film on substrate 310.

[0047] 6A, and when film formation is completed up to the edge of the film formation region of the substrate 310, the substrate holding unit 300 moves in the opposite direction of the arrow. During the reverse movement, the film formation may be continued, or the plasma may be stopped so that film formation is not performed.

[0048] Once the reverse movement is complete, if film formation was occurring during the reverse movement, power supply to the rotary targets RT1 and RT2 is stopped (step S506; plasma OFF for the first RT, plasma OFF for the second RT). As shown in FIG. 6B, the magnet positions of both rotary targets RT1 and RT2 are controlled to the film formation positions (step S507; the magnet of the first RT is controlled to the film formation position, and the magnet of the second RT is controlled to the film formation position). In this state, power is supplied to the rotary targets RT1 and RT2, and plasma is generated in both targets (step S508; plasma ON for the first RT, plasma ON for the second RT). In other words, plasma is generated at the positions where the slits 218 and 228 are provided by controlling the magnets included in the rotary targets RT1 and RT2. In this state, the substrate holder 300 holding the substrate 310 is moved in the direction of the arrow (step S509; substrate movement). In steps S508 and S509, the materials of the targets 216 and 226 attached to the rotary targets RT1 and RT2 are deposited on the substrate 310. As a result, a compound composed of the materials of the targets 216 and 226 is deposited on the substrate 310.

[0049] The power supply to the rotary targets RT1 and RT2 is stopped, the plasma generated thereon is stopped (step S510; plasma OFF to the first RT, plasma OFF to the second RT), and the supply of process gas is stopped, thereby completing the above film formation process.

[0050] In the sputtering method according to the above modification, layers with different compositions can be successively formed in the same chamber 100, as in the sputtering method according to the first embodiment.

[0051] [1-5. Variation 2 of Sputtering Method] A method for adjusting the dopant concentration in a film formed using the sputtering apparatus 10 and film formation process described above will be described. As described above, when gallium nitride is used as the target 216 and aluminum nitride is used as the target 226, the dopant concentration (aluminum concentration) in the AlGaN layer can be adjusted by adjusting the power supplied to the rotary targets RT1 and RT2. Specifically, the aluminum concentration in the AlGaN layer can be reduced by reducing the power supplied to the rotary target RT2 relative to the power supplied to the rotary target RT1. Conversely, the aluminum concentration in the AlGaN layer can be increased by increasing the power supplied to the rotary target RT2 relative to the power supplied to the rotary target RT1.

[0052] In other words, the material used for the target 226 contains more dopant than the material used for the target 216. The concentration of the dopant contained in the thin film formed on the substrate 310 is adjusted by adjusting the ratio between the power for generating plasma on the rotary target RT1 and the power for generating plasma on the rotary target RT2. Gallium nitride doped with magnesium or silicon may be used as the target 226. For example, the dopant concentration contained in the material of the target 226 may be 1 to 20 times the dopant concentration contained in the thin film formed on the substrate 310.

[0053] [1-6. Modified Example of Sputtering Apparatus] Figure 7 is a diagram showing an outline of a modified example of the sputtering apparatus according to one embodiment of the present invention. The sputtering apparatus 10 shown in Figure 7 is similar to the sputtering apparatus 10 shown in Figure 1, but the configuration of the shielding plate is different from that of the sputtering apparatus 10 in Figure 1. The other configuration in Figure 7 is the same as in Figure 1, so a description thereof will be omitted.

[0054] 7, the shielding plate 240 has a partition wall 241, a first shielding plate 242, and a second shielding plate 243. The first shielding plate 242 has a slit 244 at the same position as the slit 218 in Fig. 1. The second shielding plate 243 has a slit 245 at the same position as the slit 228 in Fig. 1.

[0055] The partition wall 241 is provided between the rotary targets RT1 and RT2. The partition wall 241 is provided to shield the space sandwiched between the rotary targets RT1 and RT2. The partition wall 241 prevents the target material sputtered from the rotary target RT1 from depositing on the rotary target RT2, and prevents the target material sputtered from the rotary target RT2 from depositing on the rotary target RT1.

[0056] The first shielding plate 242 is provided between the rotary target RT1 and the substrate holding unit 300. The first shielding plate 242 prevents the target material sputtered from the rotary target RT1 from passing through an area other than the slit 244 and depositing on the substrate 310. The second shielding plate 243 is provided between the rotary target RT2 and the substrate holding unit 300. The second shielding plate 243 prevents the target material sputtered from the rotary target RT2 from passing through an area other than the slit 245 and depositing on the substrate 310.

[0057] 7 illustrates a configuration in which the partition wall 241, the first shielding plate 242, and the second shielding plate 243 are provided as separate members, but the present invention is not limited to this configuration. For example, at least two or more members among the partition wall 241, the first shielding plate 242, and the second shielding plate 243 may be integrally formed.

[0058] As with the sputtering apparatus according to the first embodiment, the sputtering apparatus according to the above-described modified example also allows successive deposition of layers with different compositions within the same chamber 100. Note that the first shielding plate 242 and the second shielding plate 243 may be omitted. Alternatively, the partition wall 241 may be omitted.

[0059] 2. Second Embodiment A sputtering method using a sputtering apparatus 10A according to one embodiment of the present invention will be described with reference to FIGS. 8A and 8B. The configuration of the sputtering apparatus 10A used in this embodiment is the same as that of the sputtering apparatus 10 shown in FIG. 1, and therefore a description thereof will be omitted. In this embodiment, a multi-quantum well (MQW) structure of a gallium nitride layer (GaN layer) and an indium gallium nitride layer (InGaN layer) is formed using the sputtering apparatus 10A. In the following description, a description of the configuration of the sputtering apparatus 10A that is the same as that of the sputtering apparatus 10 of the first embodiment will be omitted, and the description will focus mainly on the configuration that differs from the sputtering apparatus 10. In the following description, when describing a configuration that is the same as that of the first embodiment, reference will be made to FIGS. 1 to 7, and the alphabet "A" will be added after the reference numerals shown in FIGS. 1 to 7.

[0060] 8A and 8B are diagrams illustrating a sputtering method according to one embodiment of the present invention. In this embodiment, gallium nitride is used as target 216A, and indium nitride is used as target 226A. In the following sputtering method, a GaN layer is formed in the first step, and an InGaN layer is formed in the second step. The first and second steps are alternately repeated to form an MQW structure in which GaN layers and InGaN layers are alternately stacked.

[0061] As shown in Figure 8A, by supplying power to both rotary targets RT1 and RT2, plasma is generated thereon. Gallium nitride is sputtered from rotary target RT1, and InN is sputtered from rotary target RT2. As a result, an InGaN layer is formed on substrate 310A. In this state, by moving substrate holder 300A in the direction of the arrow, an InGaN layer is formed over the entire substrate 310A. The power supplied to rotary targets RT1 and RT2 and the movement speed of substrate holder 300A are adjusted depending on the thickness of the InGaN layer to be formed. The above operation is sometimes referred to as the "first step."

[0062] After an InGaN layer of the desired thickness is formed by the operation of FIG. 8A, as shown in FIG. 8B, by stopping the supply of power to the rotary target RT2 while continuing to supply power to the rotary target RT1, plasma is generated only on the rotary target RT1. InN is not sputtered from the rotary target RT2, and gallium nitride is sputtered only from the rotary target RT1. As a result, a GaN layer is formed on the substrate 310A. In this state, the substrate holding part 300A moves in the direction of the arrow, and a GaN layer is formed over the entire substrate 310A. The power supplied to the rotary target RT1 and the movement speed of the substrate holding part 300A are adjusted depending on the thickness of the GaN layer to be formed. The above operation is sometimes referred to as the "second step."

[0063] By repeating the first and second steps, an MQW structure is formed on the substrate 310A, in which InGaN layers and GaN layers are repeatedly stacked.

[0064] In this embodiment, the method of forming each layer by moving the substrate holding unit 300A in one direction in both the first step and the second step has been exemplified, but this method is not limited to this. For example, if the desired film thickness cannot be obtained by moving in one direction alone, the substrate holding unit 300A may move back and forth one or more times in each of the first step and the second step.

[0065] Even when multiple different layers need to be repeatedly stacked, the sputtering apparatus 10A and film formation process described above allow such stacked structures to be formed in the same chamber. The sputtering method described above can prevent dust and contaminants from adhering between the InGaN layer and the GaN layer. As a result, the GaN / InGaN layer interface can be kept clean, resulting in a semiconductor device with high mobility and high reliability.

[0066] [2-2. Modified Example of Sputtering Method] Fig. 8C is a diagram illustrating a modified example of the sputtering method according to one embodiment of the present invention. A modified example of the sputtering method according to this embodiment will be described using Fig. 8C. Fig. 8C is a diagram illustrating a step that serves as an alternative to the second step in Fig. 8B. In this modified example, the first step is the same as the first step described above, and therefore a description thereof will be omitted.

[0067] In a modified example, as shown in Fig. 8C, power is supplied to both rotary targets RT1 and RT2 while the positions of the magnets (central magnet 223A and peripheral magnet 224A) of rotary target RT2 are controlled to non-film-forming positions. In this case, InN sputtered from rotary target RT2 is blocked by shielding plate 227A, and therefore, InN is not deposited on substrate 310A. As a result, only a GaN layer is deposited on substrate 310A.

[0068] 3. Third Embodiment A sputtering method using a sputtering apparatus 10B according to one embodiment of the present invention will be described with reference to FIG. 9 . The configuration of the sputtering apparatus 10B used in this embodiment is similar to that of the sputtering apparatus 10 shown in FIG. 1 , but differs from the sputtering apparatus 10 in that a linear plasma source is provided between the rotary targets RT1 and RT2. In the following description, the description of the configuration of the sputtering apparatus 10B that is the same as that of the sputtering apparatus 10 of the first embodiment will be omitted, and the description will focus mainly on the configuration that differs from the sputtering apparatus 10. In the following description, when describing the configuration that is the same as that of the first embodiment, reference will be made to FIGS. 1 to 7 , and the alphabet "B" will be added after the reference numerals shown in FIGS. 1 to 7 .

[0069] 9, the sputtering apparatus 10B includes a plasma unit 400B that generates a linear plasma between rotary targets RT1 and RT2. The plasma unit 400B includes an electrode 410B, a housing 420B, a matching box 430B, and an RF power supply 440B. The electrode 410B is disposed inside the housing 420B. The matching box 430B is disposed between the RF power supply 440B and the electrode 410B and functions as a matcher for efficiently transmitting an RF signal transmitted from the RF power supply 440B to the electrode 410B. The RF signal transmitted from the RF power supply 440B is transmitted to the electrode 410B, thereby generating a linear plasma region 411B. The plasma region 411B extends from the electrode 410B toward the substrate 310B. In particular, in this embodiment, the plasma region 411B extends toward the position where the trajectory (dotted line) of the target material sputtered from each of the rotary targets RT1 and RT2 reaches the substrate 310B.

[0070] In the case of FIG. 9 , for example, gallium nitride is used as target 216B of rotary target RT1, and indium nitride is used as target 226B. Furthermore, the plasma generated in plasma region 411B is nitrogen plasma. In this case, the ratio of nitrogen to gallium in gallium nitride used as target 216B is smaller than the ratio of nitrogen to gallium in the GaN layer to be deposited. Similarly, the ratio of nitrogen to indium in InN used as target 226B is smaller than the ratio of nitrogen to indium in the InN layer to be deposited. Even when using targets with such compositions, the sputtered target material is nitrided by nitrogen plasma on the surface of substrate 310B, allowing the formation of GaN and InGaN layers with the desired ratios.

[0071] As described above, by relatively reducing the ratio of nitrogen to gallium and indium in targets 216B and 226B, the electrical resistance of the target itself can be reduced. In a sputtering device, the target functions as a cathode. Therefore, by reducing the electrical resistance of the target itself, the film formation rate by sputtering can be increased. Metal targets of gallium and indium may be used as targets 216B and 226B instead of gallium nitride and indium nitride.

[0072] With the above configuration, it is possible to carry out a sputtering method similar to that shown in Figures 8A and 8B, and therefore, with this embodiment, it is possible to obtain the same effects as with the second embodiment.

[0073] [3-2. Modified Example of Sputtering Apparatus] Figure 10 is a diagram showing an overview of a modified example of a sputtering apparatus according to an embodiment of the present invention. As shown in Figure 10, a sputtering apparatus 10B may be configured with a rotary target RT1 and a plasma unit 400B. For example, gallium or gallium nitride is used as the target 216B. When gallium nitride is used as the target 216B, the ratio of nitrogen to gallium in the gallium nitride is smaller than the ratio of nitrogen to gallium in the GaN layer to be formed. This configuration can improve the deposition rate of the GaN layer by sputtering.

[0074] 11A to 12, a sputtering method using a sputtering apparatus 10C according to one embodiment of the present invention and a semiconductor device 50C formed by the sputtering method will be described. The configuration of the sputtering apparatus 10C used in this embodiment is similar to that of the sputtering apparatus 10 shown in FIG. 1, but differs from the sputtering apparatus 10 in that a rotary target RT3 is provided in addition to the rotary targets RT1 and RT2. In the following description, a description of the configuration of the sputtering apparatus 10C that is similar to the sputtering apparatus 10 of the first embodiment will be omitted, and the description will focus mainly on the configuration that differs from the sputtering apparatus 10. In the following description, when describing configurations similar to those of the first embodiment, reference will be made to FIGS. 1 to 7, and the alphabet "C" will be added after the reference numerals shown in FIGS. 1 to 7.

[0075] 11A, the sputtering apparatus 10C includes a rotary target RT3 in addition to the rotary targets RT1 and RT2. Like the rotary targets RT1 and RT2, the rotary target RT3 includes a support member 230C, a fixing member 231C, a yoke 232C, a central magnet 233C, a peripheral magnet 234C, a backing tube 235C, and a target 236C. The rotary target RT3 is surrounded by a shielding plate 237C. Each of the above components constituting the rotary target RT3 has a shape extending in the Z direction. The rotary target RT3 is disposed spaced apart from the rotary targets RT1 and RT2 in the X direction. The configuration of the rotary target RT3 is similar to that of the rotary targets RT1 and RT2, and therefore detailed description thereof will be omitted.

[0076] The slit 218C is provided on the rotary target RT2 side of a line perpendicular to the surface of the substrate holder 300C or the substrate 310C that passes through the rotation axis of the rotary target RT1. The slit 238C is provided on the rotary target RT2 side of a line perpendicular to the surface that passes through the rotation axis of the rotary target RT3. The shielding plate 227C is provided with slits 228C and 229C. The slit 228C is provided on the rotary target RT1 side of a line perpendicular to the surface that passes through the rotation axis of the rotary target RT2. The slit 229C is provided on the rotary target RT3 side of a line perpendicular to the surface that passes through the rotation axis of the rotary target RT2.

[0077] The positions of the magnets (central magnet 223C and peripheral magnet 224C) of rotary target RT2 are controllable. As shown in Figures 11A and 11B, the position of the magnets when the sputtered target material passes through slit 228C and is deposited on substrate 310C may be referred to as the "first film deposition position." As shown in Figure 11C, the position of the magnets when the sputtered target material passes through slit 229C and is deposited on substrate 310C may be referred to as the "second film deposition position."

[0078] 11A to 11C are diagrams illustrating a sputtering method according to one embodiment of the present invention. In this embodiment, aluminum nitride (AlN) is used as target 216C, gallium nitride is used as target 226C, and magnesium-doped gallium nitride is used as target 236C. Because magnesium-doped gallium nitride functions as a P-type semiconductor, this gallium nitride layer is sometimes referred to as a "p-GaN layer." In the following sputtering method, a GaN layer is formed in the first step, an AlGaN layer is formed in the second step, and a p-GaN layer is formed in the third step. By performing the first to third steps, a HEMT (High Electron Mobility Transistor) shown in FIG. 12 (described later) can be formed. The dopant concentration contained in the material of target 236C is 1 to 20 times the dopant concentration contained in the thin film to be deposited on substrate 310C.

[0079] As shown in FIG. 11A , power is supplied to the rotary target RT2 to generate plasma. Gallium nitride is sputtered from the rotary target RT2. As a result, a GaN layer is formed on the substrate 310A. In this state, the substrate holder 300C moves in the direction of the arrow, thereby forming a GaN layer over the entire substrate 310C. The power supplied to the rotary target RT2 and the movement speed of the substrate holder 300C are adjusted depending on the thickness of the GaN layer to be formed. This operation is sometimes referred to as the "first step." While FIG. 11A illustrates a configuration in which the magnet of the rotary target RT2 is positioned at the first film formation position, the magnet may be positioned at the second film formation position.

[0080] After a GaN layer of the desired thickness is formed by the operation of FIG. 11A, power is supplied to both rotary targets RT1 and RT2, generating plasma therefor, as shown in FIG. 11B. In this case, the magnet of rotary target RT2 is positioned at the first film formation position. Aluminum nitride is sputtered from rotary target RT1, and gallium nitride is sputtered from rotary target RT2. As a result, an AlGaN layer is formed on substrate 310C. In this state, substrate holder 300C moves in the direction of the arrow, thereby forming an AlGaN layer over the entire substrate 310C. The power supplied to rotary targets RT1 and RT2 and the movement speed of substrate holder 300C are adjusted depending on the thickness of the AlGaN layer to be formed. The above operation is sometimes referred to as the "second step."

[0081] After depositing an AlGaN layer of the desired thickness through the operation of FIG. 11B, the position of the magnet of rotary target RT2 is switched to the second deposition position, and power is supplied to both rotary targets RT2 and RT3, generating plasma for these targets, as shown in FIG. 11C. Gallium nitride is sputtered from rotary target RT2, and magnesium-containing gallium nitride is sputtered from rotary target RT3. As a result, a p-GaN layer is deposited on substrate 310C. The above operation is sometimes referred to as the "third step."

[0082] In the third step, the concentration of dopants contained in the thin film formed on the substrate 310C can be adjusted by adjusting the ratio between the power for generating plasma on the rotary target RT2 and the power for generating plasma on the rotary target RT3.

[0083] 11A to 11C, a p-GaN layer / AlGaN layer / GaN layer is formed. In other words, the sputtering apparatus 10C according to this embodiment can prevent dust and contaminants from adhering to the interface of a stacked structure such as a p-GaN layer / AlGaN layer / GaN layer.

[0084] Aluminum (Al) may be used as target 216C. Gallium (Ga) may be used as target 226C. The dopant concentration of the magnesium-containing gallium nitride used as target 236C may be the same as the dopant concentration of the p-GaN layer formed on substrate 310C, or may be higher than the dopant concentration of the p-GaN layer formed on substrate 310C. In this case, the dopant concentration of the magnesium-containing gallium nitride used as target 236C may be 1 to 20 times the dopant concentration of the p-GaN layer formed on substrate 310C.

[0085] 4-3. Semiconductor Device 50C Manufactured Using Sputtering Apparatus 10C FIG. 12 is a cross-sectional view showing a semiconductor device manufactured using a sputtering method according to one embodiment of the present invention.

[0086] 12 , the semiconductor device 50C includes a substrate 501C, a barrier layer 502C, a buffer layer 503C, a GaN layer 504C, a first AlGaN layer 505C, a second AlGaN layer 506C, a third AlGaN layer 507C, a source electrode 508C, a drain electrode 509C, a gate electrode 510C, a first insulating layer 511C, a second insulating layer 512C, and a shield electrode 513C. The semiconductor device 50C is a so-called HEMT, but is not limited to this.

[0087] The substrate 501C may be, for example, a glass substrate or a quartz substrate. The barrier layer 502C may be, for example, a silicon nitride film. The buffer layer 503C may be, for example, an aluminum nitride film. The GaN layer 504C may be an intrinsic gallium nitride layer. The first AlGaN layer 505C may be an intrinsic aluminum gallium nitride layer. The second AlGaN layer 506C may be, for example, a magnesium-doped aluminum gallium nitride layer. The third AlGaN layer 507C may be an intrinsic aluminum gallium nitride layer.

[0088] The source electrode 508C and the drain electrode 509C may be made of a metal such as titanium or aluminum. The gate electrode 510C may be made of a metal such as nickel or gold. The first insulating layer 511C may be made of a silicon nitride layer. The second insulating layer 512C may be made of a silicon oxide layer. The shield electrode 513C may be made of a laminated metal such as aluminum / titanium (Al / Ti). The barrier layer 502C may be omitted.

[0089] The semiconductor device 50C is manufactured as follows: First, a silicon nitride layer and an aluminum nitride layer are sequentially formed on a substrate 501C to form a barrier layer 502C and a buffer layer 503C. Next, a gallium nitride layer, an aluminum gallium nitride layer, a magnesium-containing aluminum gallium nitride layer, and an aluminum gallium nitride layer are formed on the buffer layer 503C to form a GaN layer 504C, a first AlGaN layer 505C, a second AlGaN layer 506C, and a third AlGaN layer 507C.

[0090] Next, the third AlGaN layer 507C is etched using a photolithography process to expose a portion of the second AlGaN layer 506C. A source electrode 508C and a drain electrode 509C are formed on the exposed second AlGaN layer 506C. A gate electrode 510C is formed on the third AlGaN layer 507C. A silicon nitride film and a silicon oxide film are sequentially deposited to cover the source electrode 508C, the drain electrode 509C, and the gate electrode 510C, forming a first insulating layer 511C and a second insulating layer 512C. A shield electrode 513C is formed on the second insulating layer 512C, thereby completing the semiconductor device 50C.

[0091] In this embodiment, the GaN layer 504C, the first AlGaN layer 505C, the second AlGaN layer 506C, and the third AlGaN layer 507C can be deposited in the same chamber 100C using the sputtering apparatus 10C. This makes it possible to prevent dust and contaminants from adhering to the interfaces between these layers.

[0092] Furthermore, the semiconductor device 50C according to this embodiment can be manufactured using a substrate with low heat resistance, such as a glass substrate, because the gallium nitride film can be formed using the sputtering apparatus 10C.

[0093] 13 and 14 , a sputtering apparatus 10D according to one embodiment of the present invention and a light-emitting device 70D formed using the sputtering apparatus 10D will be described. In the following description, a description of the configuration of the sputtering apparatus 10D that is the same as that of the sputtering apparatus 10 of the first embodiment will be omitted, and the description will focus mainly on the configuration that differs from the sputtering apparatus 10. In the following description, when describing the same configuration as that of the first embodiment, reference will be made to FIGS. 1 to 7, and the alphabet "D" will be added after the reference numerals shown in FIGS. 1 to 7.

[0094] 13 is a diagram showing an outline of a sputtering apparatus according to one embodiment of the present invention. As shown in FIG. 13, the sputtering apparatus 10D includes a transfer chamber 600D, a first deposition chamber 610D, a second deposition chamber 620D, a third deposition chamber 630D, a fourth deposition chamber 640D, a fifth deposition chamber 650D, and a load lock chamber 660D.

[0095] A transfer robot that transfers the substrate 310D is disposed in the transfer chamber 600D. Gate shutters are disposed between the transfer chamber 600D and each chamber. When the gate shutter is open, the spaces between adjacent chambers are continuous. When the gate shutter is closed, the spaces between adjacent chambers are cut off, and the atmosphere in each chamber can be controlled individually. The load lock chamber 660D is a chamber that transfers the substrate 310D into and out of the sputtering apparatus 10D and the outside.

[0096] A silicon nitride target is disposed in the first deposition chamber 610D. An aluminum nitride target is disposed in the second deposition chamber 620D. An aluminum nitride target, a gallium nitride target, and a silicon-doped gallium nitride (N-type semiconductor) target are disposed in the third deposition chamber 630D. That is, the third deposition chamber 630D has the same configuration as the sputtering apparatus 10C according to the fourth embodiment, as shown in FIG. 11A and other figures. A gallium nitride target and an indium nitride target are disposed in the fourth deposition chamber 640D. That is, the fourth deposition chamber 640D has the same configuration as the sputtering apparatus 10A according to the second embodiment, as shown in FIG. 8A and other figures. The fifth deposition chamber 650D has an aluminum nitride target, a gallium nitride target, and a magnesium-doped gallium nitride (P-type semiconductor) target. That is, the fifth deposition chamber 650D has the same configuration as the sputtering apparatus 10C according to the fourth embodiment, as shown in FIG. 11A and other figures.

[0097] 5-2. Light-emitting device 70D manufactured using sputtering apparatus 10D FIG. 14 is a cross-sectional view showing a light-emitting device manufactured using a sputtering method according to one embodiment of the present invention.

[0098] 14 , the light emitting element 70D includes a substrate 701D, a barrier layer 702D, a buffer layer 703D, an N-type semiconductor layer 704D, a light emitting layer 705D, a P-type semiconductor layer 706D, an N-type electrode 707D, and a P-type electrode 708D. The light emitting element 70D is a so-called LED (Light Emitting Diode), but is not limited to this.

[0099] The substrate 701D may be, for example, a glass substrate or a quartz substrate. The barrier layer 702D may be, for example, a silicon nitride layer. The buffer layer 703D may be, for example, an aluminum nitride layer. The N-type semiconductor layer 704D may be, for example, a silicon-doped gallium nitride layer. The light-emitting layer 705D may be, for example, a stack of alternating indium gallium nitride layers and gallium nitride layers. The P-type semiconductor layer 706D may be, for example, a magnesium-doped gallium nitride layer. The N-type electrode 707D may be, for example, a metal such as indium. The P-type electrode 708D may be, for example, a metal such as palladium or gold. The barrier layer 702D may be omitted.

[0100] The light-emitting element 70D is manufactured as follows: First, a silicon nitride layer and an aluminum nitride layer are sequentially formed on a substrate 701D to form a barrier layer 702D and a buffer layer 703D. Next, a silicon-doped gallium nitride layer is formed on the buffer layer 703D, and then indium gallium nitride layers and gallium nitride layers are alternately formed thereon, followed by a magnesium-doped gallium nitride layer thereon, thereby forming an N-type semiconductor layer 704D, a light-emitting layer 705D, and a P-type semiconductor layer 706D.

[0101] Next, a photolithography process is performed to etch the P-type semiconductor layer 706D, the light-emitting layer 705D, and a portion of the N-type semiconductor layer 704D so that a portion of the N-type semiconductor layer 704D is exposed. An N-type electrode 707D is formed on the exposed N-type semiconductor layer 704D. Similarly, a P-type electrode 708D is formed on the P-type semiconductor layer 706D.

[0102] In this embodiment, the sputtering apparatus 10D can be used to deposit the N-type semiconductor layer 704D, the light-emitting layer 705D, and the P-type semiconductor layer 706D in the same chamber, thereby preventing dust and contaminants from adhering to their interfaces.

[0103] In the above embodiment, the target provided in the sputtering device is a rotary target, but a flat target may be used instead of the rotary target.

[0104] The above-described embodiments of the present invention may be combined as appropriate as long as they are not mutually inconsistent. Furthermore, even if a person skilled in the art appropriately adds or deletes components or modifies the design, or adds or omits steps or modifies conditions based on the embodiments, such combinations are included within the scope of the present invention as long as they include the gist of the present invention.

[0105] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention.

[0106] 10: Sputtering apparatus, 20: Semiconductor device, 50C: Semiconductor device, 70D: Light emitting element, 100: Chamber, 200: Target portion, 210, 220, 230C: Support member, 211, 221, 231C: Fixing member, 212, 222, 232C: Yoke, 213, 223, 233C: Central magnet, 214, 224, 234C: Peripheral magnet, 215, 225, 235C: Backing tube, 216, 226, 236C: Target, 217, 227, 237C: Shielding plate, 218, 228, 229C, 238C: Slit, 240: Shielding plate, 241: Partition wall, 242: First shielding plate, 243: Second shielding plate, 244, 245: Slits, 300: Substrate holder, 310: Substrate, 320: Moving mechanism, 330: First gallium nitride layer, 340: Second gallium nitride layer, 350: Gate insulating layer, 360: Gate electrode, 370: Source electrode, 380: Drain electrode, 400B: Plasma unit, 410B: Electrode, 411B: Plasma region, 420B: Housing, 430B: Matching box, 440B: RF power supply, 501C: Substrate, 502C: Barrier layer, 503C: Buffer layer, 504C: Gallium nitride layer (GaN layer), 505C: First aluminum gallium nitride layer (first AlGaN layer), 506C: Second aluminum gallium nitride layer (second AlGaN layer), 507C: third aluminum gallium nitride layer (third AlGaN layer), 508C: source electrode, 509C: drain electrode, 510C: gate electrode, 511C: first insulating layer, 512C: second insulating layer, 513C: shield electrode, 600D: transfer chamber, 610D: first film formation chamber, 620D: second film formation chamber, 630D: third film formation chamber, 640D: fourth film formation chamber, 650D: fifth film formation chamber, 660D: load lock chamber, 701D: substrate, 702D: barrier layer, 703D: buffer layer, 704D: N-type semiconductor layer, 705D: light-emitting layer, 706D: P-type semiconductor layer, 707D: N-type electrode, 708D: P-type electrode, PLS: plasma region, RT1, RT2, RT3: Rotary Target

Claims

1. A sputtering apparatus comprising: a substrate holding part for holding a substrate; a first target arranged to face the substrate holding part; a second target arranged alongside the first target to face the substrate holding part; and a partition wall arranged between the first target and the second target, wherein a first normal at an arbitrary position of the first target and a second normal at an arbitrary position of the second target are each connected to an arbitrary point on the substrate.

2. The sputtering apparatus according to claim 1, wherein the partition is arranged so as to shield the space between the first target and the second target.

3. The sputtering apparatus of claim 1, further comprising: a first shielding plate having a first slit arranged between the substrate holding portion and the first target; and a second shielding plate having a second slit arranged between the substrate holding portion and the second target.

4. The sputtering apparatus according to claim 3, wherein the first shielding plate and the second shielding plate are connected to the partition wall.

5. A sputtering apparatus as described in claim 3, wherein the first shielding plate continuously surrounds the first target except for the area where the first slit is provided, and the second shielding plate continuously surrounds the second target except for the area where the second slit is provided.

6. A sputtering apparatus as described in claim 3, wherein the first slit is provided on the second target side of a line perpendicular to the substrate holding part or the substrate that passes through the rotation axis of the first target, and the second slit is provided on the first target side of a line perpendicular to the substrate holding part or the substrate that passes through the rotation axis of the second target.

7. A sputtering apparatus comprising: a substrate holding part for holding a substrate; a first target arranged opposite the substrate holding part and having a first target member attached thereto; and a second target arranged alongside the first target opposite the substrate holding part and having a second target member different from the first target member attached thereto, wherein the first target member contains gallium.

8. The sputtering apparatus of claim 7, further comprising a partition disposed between said first target and said second target.

9. The sputtering apparatus according to claim 8, wherein the partition is provided so as to shield the space between the first target and the second target.

10. The sputtering apparatus of claim 7, further comprising: a first shielding plate having a first slit disposed between the substrate holding portion and the first target; and a second shielding plate having a second slit disposed between the substrate holding portion and the second target.

11. The sputtering apparatus according to claim 10, wherein the first shielding plate and the second shielding plate are connected to the partition wall.

12. A sputtering apparatus as described in claim 10, wherein the first shielding plate continuously surrounds the first target except for the area where the first slit is provided, and the second shielding plate continuously surrounds the second target except for the area where the second slit is provided.

13. A sputtering apparatus as described in claim 10, wherein the first slit is provided on the second target side of a line perpendicular to the substrate holding part or the substrate that passes through the rotation axis of the first target, and the second slit is provided on the first target side of a line perpendicular to the substrate holding part or the substrate that passes through the rotation axis of the second target.

14. A sputtering method for forming a layered structure including the first material and the second material, comprising: holding a substrate on a substrate holding part facing a first target and a second target; in a first step, generating plasma for the first target while moving the first target and the substrate holding part relatively to each other, thereby depositing a first material of the first target onto the substrate; and in a second step, generating plasma for the second target while moving the second target and the substrate holding part relatively to each other, thereby depositing a second material of the second target onto the substrate.

15. A sputtering method as described in claim 14, wherein in the first step, plasma for the second target is stopped when depositing the first material on the substrate, and in the second step, plasma for the first target and plasma for the second target are generated to deposit the first material and the second material on the substrate.

16. A sputtering method as described in claim 14, wherein, when depositing the first material on the substrate, a first magnet included in the first target is controlled to generate plasma at a position where a first slit is provided, and, when depositing the second material on the substrate, a second magnet included in the second target is controlled to generate plasma at a position where a second slit is provided.

17. The sputtering method according to claim 14, wherein the second material contains more dopant than the first material, and the concentration of the dopant contained in the thin film formed on the substrate is adjusted by adjusting the power for generating plasma with respect to the second target.

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