Film forming device and film forming method

Abstract

The present invention provides a film forming device and a film forming method capable of forming a GaN film with high productivity. The film forming device (1) of the embodiment includes: a chamber (20) capable of making the interior thereof vacuum; a rotating table (31) disposed in the chamber (20), holding a workpiece (10), and cyclically conveying the workpiece (10) in a circular trajectory; a GaN film forming processing unit (40A) having a target containing a film forming material containing GaN, and a plasma generator for plasma-forming a sputtering gas (G1) introduced between the target and the rotating table, so that particles of the film forming material containing GaN and Ga are deposited on the workpiece (10) cyclically conveyed by the rotating table (31) by sputtering; and a nitriding processing unit (50) for nitriding the particles of the film forming material deposited in the GaN film forming processing unit (40A) on the workpiece (10) cyclically conveyed by the rotating table (31).

Description

Technical Field

[0001] The invention relates to a film forming device and a film forming method. Background Art

[0002] GaN (Gallium Nitride) is attracting attention as a next-generation device material. For example, devices using GaN include light-emitting devices, power devices, and high-frequency communication devices. Such GaN devices are manufactured by forming a GaN film on a silicon (Si) wafer, a silicon carbide (SiC) wafer, a sapphire substrate, or a glass substrate. Previously, GaN film formation was performed using the metal organic chemical vapor deposition (MO-CVD) method. The MO-CVD method is a film formation method in which a material gas containing an organic metal is transported on a heated substrate using a carrier gas, and the material is decomposed at high temperature to undergo a chemical reaction to deposit a film using chemical vapor deposition.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-103652 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, the film formation of GaN using the MO-CVD method has problems in productivity as follows. First, gallium (Ga) is a liquid at room temperature and pressure, but in order to suppress the evaporation of Ga and make Ga react with nitrogen (N), a large amount of NH3 gas used in the process is required. Therefore, the material utilization efficiency is poor. Furthermore, the material gas is difficult to handle, and it is difficult to stably maintain the state of the device, so the yield is poor. In order to completely decompose the NH3 gas, the MO-CVD method requires high-temperature treatment at the level of 1000°C, and a high-output heating device is required, which increases the cost. In addition, during the process, the hydrogen (H) contained in the process gas will be incorporated into the formed GaN film, so unnecessary steps such as dehydrogenation treatment are required.

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a film forming apparatus and a film forming method capable of forming a GaN film with high productivity.

[0009] Technical means of solving problems

[0010] In order to achieve the above-mentioned purpose, the film forming device of the present embodiment includes: a chamber capable of making the interior of the chamber a vacuum; a turntable arranged in the chamber, holding a workpiece, and cyclically transporting the workpiece in a circular trajectory; a GaN film forming processing section, having a target containing a film forming material containing GaN, and a plasma generator for plasmatizing a sputtering gas introduced between the target and the turntable, so that particles of the film forming material containing GaN are deposited on the workpiece cyclically transported by the turntable by sputtering; and a nitriding processing section, which nitrides the particles of the film forming material deposited in the GaN film forming processing section on the workpiece cyclically transported by the turntable.

[0011] The film forming method of this embodiment is to hold a workpiece by a turntable and cyclically transport the workpiece in a circular trajectory in a chamber capable of making the interior of the chamber vacuum, and to form a film on the workpiece at the same time, and the film forming method includes: a GaN film forming process, a GaN film forming process part deposits particles of a film forming material containing GaN on the workpiece cyclically transported by the turntable by sputtering, the GaN film forming process part having a target containing a film forming material containing GaN and a plasma generator for plasmatizing a sputtering gas introduced between the target and the turntable; and a nitridation process, a nitridation process part nitridates the particles of the film forming material deposited in the GaN film forming process part on the workpiece cyclically transported by the turntable.

[0012] Effects of the Invention

[0013] According to the embodiment of the present invention, a film forming apparatus and a film forming method capable of forming a GaN film with high productivity can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective plan view schematically showing the structure of a film forming apparatus according to an embodiment.

[0015] Figure 2 yes Figure 1 The AA section view in Figure 1 A detailed view of the internal structure of a film-forming device according to an embodiment of the present invention as viewed from the side.

[0016] Figure 3 This is a flowchart of a process performed by the film forming apparatus according to the embodiment.

[0017] Figure 4 It is a perspective plan view schematically showing a modification of the embodiment.

[0018] Figure 5 It is a perspective plan view schematically showing a modification of the embodiment.

[0019] Figure 6(A) is a cross-sectional view showing an example of a layer structure of a light emitting diode (LED). Figure 6 (B) is an enlarged cross-sectional view of the buffer layer.

[0020] [Explanation of Symbols]

[0021] 1: Film forming device

[0022] 10: Artifacts

[0023] 11: Buffer layer

[0024] 12: GaN layer

[0025] 13: GaN layer

[0026] 14: Luminous layer

[0027] 15: Transparent conductive film

[0028] 20: Chamber

[0029] 20a: Top

[0030] 20b: Inner bottom surface

[0031] 20c: Inner circumference

[0032] 21: Exhaust port

[0033] 22: Divider

[0034] 23: Exhaust

[0035] 30: Transport Department

[0036] 31: Rotating table

[0037] 32: Motor

[0038] 33: Maintaining Department

[0039] 34: Pallet

[0040] 40: Film forming processing department

[0041] 40A: GaN film forming processing unit

[0042] 40B: Al film forming processing unit

[0043] 40C: Mg film forming processing unit

[0044] 40D: Si film forming processing unit

[0045] 40E: InN film forming processing department

[0046] 41: Processing Space

[0047] 42: Target

[0048] 43: Support plate

[0049] 44: Electrode

[0050] 46: Power supply department

[0051] 47: Gas inlet

[0052] 48: Piping

[0053] 49: Sputtering gas inlet

[0054] 50: Nitriding treatment department

[0055] 51: Cylindrical body

[0056] 52: Window components

[0057] 53: Antenna

[0058] 54: RF power supply

[0059] 55: Matching box

[0060] 56: Gas inlet

[0061] 57: Piping

[0062] 58: Process gas introduction part

[0063] 59: Processing Space

[0064] 60: Heating unit

[0065] 70: Transfer Room

[0066] 71: Load lock unit

[0067] 80: Preparatory heating chamber

[0068] 90: Cooling room

[0069] 100: Control device DETAILED DESCRIPTION

[0070] Embodiments of the film forming apparatus will be described in detail with reference to the drawings.

[0071] [summary]

[0072] Figure 1 The film forming apparatus 1 shown is an apparatus for forming a GaN (Gallium Nitride) film or an AlN (Aluminum Nitride) film by sputtering on a workpiece 10 as a film forming target. The workpiece 10 is, for example, a silicon (Si) wafer, a silicon carbide (SiC) wafer, a sapphire substrate, or a glass substrate.

[0073] The film forming apparatus 1 comprises: a chamber 20, a conveying section 30, a film forming processing section 40, a nitriding processing section 50, a heating section 60, a transfer chamber 70, a preheating chamber 80, a cooling chamber 90, and a control device 100. The chamber 20 is a container capable of making the interior thereof vacuum. The chamber 20 is cylindrical in shape, and the interior thereof is divided into a plurality of partitions. The film forming processing section 40 is divided by a partition 22 and is arranged in two partitions divided in a fan shape. The nitriding processing section 50 and the heating section 60 are arranged in the partition other than the partition in which the film forming processing section 40 is arranged.

[0074] The film forming section 40 includes a GaN film forming section 40A for forming a GaN film using a GaN-containing material as a target 42, and an Al film forming section 40B for forming an Al film using an Al-containing material as a target 42. The workpiece 10 is rotated several times in the circumferential direction in the chamber 20, alternately passing through the GaN film forming section 40A and the nitridation section 50, and the formation of the GaN film and the nitridation of Ga are alternately repeated on the workpiece 10, thereby growing a GaN film of a desired thickness.

[0075] In addition, the workpiece 10 circulates several times in the circumferential direction in the chamber 20, alternately passing through the Al film forming processing section 40B and the nitriding processing section 50, and the formation of the Al film and the nitriding of Al are alternately repeated on the workpiece 10, so that an AlN film of a desired thickness grows. In this way, the formation of the GaN film and the formation of the AlN film are repeated, and the GaN film and the AlN film are alternately stacked.

[0076] The reason why the nitriding treatment unit 50 is further provided while using a material containing GaN as the target 42 is as follows. That is, since Ga has a low melting point and is in a liquid state at normal temperature and pressure, it is necessary to contain nitrogen (N) in order to form a solid target 42. Therefore, it is also possible to simply increase the nitrogen content of the target 42 and form a film only by sputtering the target 42.

[0077] Here, in order to increase the film forming rate, direct current (DC) discharge sputtering is preferred over radio frequency (RF) discharge. However, if the target 42 contains a large amount of nitrogen, the surface will become an insulator. In this way, in the target 42 whose surface becomes an insulator, a situation where DC discharge is not generated may occur.

[0078] That is, there is a limit to the amount of nitrogen that can be contained in the GaN target 42, and the nitridation of Ga in the target 42 remains insufficient. That is, the target 42 containing GaN contains Ga atoms whose bonds with N (nitrogen) atoms are defective.

[0079] In addition, when nitrogen is added to the sputtering gas introduced into the film forming processing unit 40 for sputtering, the surface of the target 42 is nitrided and the surface becomes an insulator. Therefore, in order to make up for the insufficient nitrogen, the GaN film forming processing unit 40A cannot add nitrogen to the sputtering gas. On the other hand, if the nitrogen content in the formed GaN film is low and there are nitrogen defects, the crystallinity of the film deteriorates and the flatness is impaired. Therefore, in order to make up for the insufficient nitrogen in the GaN film formed by the GaN film forming processing unit 40A, after the film is formed by the GaN film forming processing unit 40A, it is further nitrided by the nitridation processing unit 50.

[0080] [Chamber]

[0081] like Figure 2 As shown in the figure, the chamber 20 is formed by a disk-shaped top 20a, a disk-shaped inner bottom surface 20b, and an annular inner peripheral surface 20c. The partition 22 is a square wall plate arranged radially from the center of the cylindrical shape, and extends from the top 20a toward the inner bottom surface 20b, but does not reach the inner bottom surface 20b. That is, a cylindrical space is ensured on the inner bottom surface 20b side.

[0082] A rotating table 31 for conveying the workpiece 10 is arranged in the cylindrical space. The lower end of the partition 22 is open to a gap through which the workpiece 10 placed on the rotating table 31 passes, and faces the placement surface of the workpiece 10 in the rotating table 31. The processing space 41 for processing the workpiece 10 by the film forming processing section 40 is divided by the partition 22. In addition, the processing space 59 is divided by the cylindrical body 51 of the nitriding processing section 50 described later. That is, the film forming processing section 40 and the nitriding processing section 50 respectively have a processing space 41 and a processing space 59 that are smaller than the chamber 20 and are separated from each other. The partition 22 can suppress the sputtering gas G1 of the film forming processing section 40 from diffusing into the chamber 20. In addition, the cylindrical body 51 of the nitriding processing section 50 can suppress the process gas G2 from diffusing into the chamber 20.

[0083] In addition, as described later, in the film forming processing unit 40 and the nitriding processing unit 50, plasma is generated in the processing space 41 and the processing space 59, but it is sufficient to adjust the pressure in the processing space 41 and the processing space 59 which are divided into spaces smaller than the chamber 20, so the pressure can be easily adjusted and the discharge of plasma can be stabilized. Therefore, as long as the above-mentioned effect can be obtained, at least two partitions 22 sandwiching the film forming processing unit 40 in a plan view are sufficient.

[0084] Furthermore, the chamber 20 is provided with an exhaust port 21. An exhaust unit 23 is connected to the exhaust port 21. The exhaust unit 23 has a pipe and a pump and a valve (not shown). By exhausting the air through the exhaust port 21 using the exhaust unit 23, the chamber 20 can be decompressed to form a vacuum. In order to suppress the oxygen concentration to a low level, the exhaust unit 23 exhausts the air until the vacuum degree reaches 10 -4 Pa until now.

[0085] [Transportation Department]

[0086] The conveying unit 30 includes a rotating table 31, a motor 32, and a holding unit 33, and cyclically conveys the workpiece 10 along a conveying path L which is a circular trajectory. The rotating table 31 has a disk shape and is greatly expanded to a degree that does not contact the inner peripheral surface 20c. The motor 32 continuously rotates at a predetermined rotation speed with the center of the circle of the rotating table 31 as a rotation axis. The rotating table 31 rotates at a speed of 1 rpm to 150 rpm, for example.

[0087] The holding part 33 is a groove, a hole, a protrusion, a jig, a fixture, etc. arranged at a circumferentially uniform position on the upper surface of the rotating table 31, and a tray 34 carrying the workpiece 10 is held by a mechanical chuck or an adhesive chuck. The workpieces 10 are arranged on the tray 34 in a matrix shape, for example, and six holding parts 33 are arranged at 60° intervals on the rotating table 31. That is, the film forming apparatus 1 can perform film formation on a plurality of workpieces 10 held by a plurality of holding parts 33 at a time, so the productivity is very high. Furthermore, the tray 34 can be omitted, and the workpiece 10 can be directly placed on the upper surface of the rotating table 31.

[0088] [Film Forming Processing Department]

[0089] The film forming processing unit 40 generates plasma and exposes a target 42 containing a film forming material to the plasma. As a result, particles of the film forming material (hereinafter referred to as sputtered particles) knocked out by ions contained in the plasma colliding with the target 42 are deposited on the workpiece 10 to form a film. Figure 2 As shown, the film forming processing unit 40 includes: a sputtering source including a target 42 , a support plate 43 , and an electrode 44 ; and a plasma generator including a power supply unit 46 and a sputtering gas introduction unit 49 .

[0090] The target 42 is a plate-shaped member containing a film-forming material that is deposited on the workpiece 10 to form a film. The film-forming material constituting the target 42 in the GaN film-forming processing unit 40A of the present embodiment is a material containing Ga and GaN, and the target 42 becomes a supply source of sputtered particles containing Ga atoms that are deposited on the workpiece 10. Since the nitrogen content is limited as described above, the target 42 contains GaN and incomplete GaN lacking nitrogen, that is, Ga atoms whose bonding with N (nitrogen) is defective.

[0091] In addition, the film forming material constituting the target 42 in the Al film forming processing unit 40B is a material containing Al, and the target 42 becomes a supply source of sputtered particles containing Al atoms deposited on the workpiece 10. Furthermore, if the target 42 for sputtering can supply sputtered particles containing Ga atoms and sputtered particles containing Al atoms, it is allowed even if it does not contain Ga, Al, and N (nitrogen).

[0092] The target 42 is disposed at a distance on the transport path L of the workpiece 10 mounted on the rotating table 31. The surface of the target 42 is held on the top 20a of the chamber 20 so as to face the workpiece 10 mounted on the rotating table 31. For example, three targets 42 are disposed. The three targets 42 are disposed at positions arranged at the vertices of a triangle in a plan view.

[0093] The support plate 43 is a support member for holding the target 42. The support plate 43 holds each target 42 individually. The electrode 44 is a conductive member for applying power to each target 42 individually from the outside of the chamber 20, and is electrically connected to the target 42. The power applied to each target 42 can be changed individually. In addition, in the sputtering source, a magnet, a cooling mechanism, etc. are appropriately included as needed.

[0094] The power supply unit 46 is, for example, a DC power supply that applies a high voltage, and is electrically connected to the electrode 44. The power supply unit 46 applies power to the target 42 via the electrode 44. The potential of the rotary table 31 is the same as that of the grounded chamber 20, and a potential difference is generated by applying a high voltage to the target 42 side.

[0095] like Figure 2 As shown, the sputtering gas introduction part 49 introduces the sputtering gas G1 into the chamber 20. The sputtering gas introduction part 49 has a supply source of the sputtering gas G1 such as a gas bottle (not shown), a pipe 48, and a gas introduction port 47. The pipe 48 is connected to the supply source of the sputtering gas G1, passes through the chamber 20 in an airtight manner and extends to the inside of the chamber 20, and its end is opened as the gas introduction port 47. The sputtering gas introduction part 49 of this embodiment introduces the sputtering gas G1 into the processing space 41 in a manner that the processing space 41 becomes 0.3Pa or less and 0.1Pa or more.

[0096] The gas inlet 47 opens between the rotating table 31 and the target 42, and introduces the sputtering gas G1 for film formation into the processing space 41 formed between the rotating table 31 and the target 42. As the sputtering gas G1, a rare gas can be used, and argon (Ar) gas is suitable. The sputtering gas G1 is a gas that does not contain nitrogen (N), and can be set to a single gas of argon (Ar).

[0097] In such a film forming processing unit 40, if the sputtering gas G1 is introduced from the sputtering gas introduction unit 49, and the power supply unit 46 applies a high voltage to the target 42 via the electrode 44, the sputtering gas G1 introduced into the processing space 41 formed between the rotating table 31 and the target 42 is plasmatized, and active species such as ions are generated. The ions in the plasma collide with the target 42 to knock out sputtered particles. In the GaN film forming processing unit 40A, the target 42 containing a material containing Ga and GaN collides with the target 42 to knock out sputtered particles containing Ga atoms. In the Al film forming processing unit 40B, the target 42 containing a material containing Al collides with the target 42 to knock out sputtered particles containing Al atoms.

[0098] In addition, the workpiece 10 cyclically transported by the rotating table 31 passes through the processing space 41. The sputtered particles knocked out are deposited on the workpiece 10 when the workpiece 10 passes through the processing space 41, and a film containing Ga atoms or a film containing Al atoms is formed on the workpiece 10. The workpiece 10 is cyclically transported by the rotating table 31 and repeatedly passes through the processing space 41, thereby performing film forming processing. Furthermore, the formation of the GaN film containing Ga and the formation of the AlN film containing Al are not performed in parallel, but are performed by forming one film after the other film is formed.

[0099] [Nitriding treatment department]

[0100] The nitridation treatment section 50 generates inductively coupled plasma in the treatment space 59 into which the process gas G2 containing nitrogen is introduced. That is, the nitridation treatment section 50 converts the nitrogen gas into plasma to generate chemical species. Nitrogen atoms contained in the generated chemical species collide with the film containing Ga atoms and the film containing Al atoms formed on the workpiece 10 by the film forming treatment section 40, and bond with Ga atoms in the film containing Ga atoms and nitrogen in which the bonding is defective, and Al atoms in the film containing Al atoms. Thus, a GaN film or an AlN film without nitrogen defects can be obtained.

[0101] like Figure 2 As shown, the nitriding treatment unit 50 has a plasma generator including a cylindrical body 51 , a window member 52 , an antenna 53 , an RF power source 54 , a matching box 55 , and a process gas introduction unit 58 .

[0102] The cylindrical body 51 is a member covering the periphery of the processing space 59. The cylindrical body 51 is as follows Figure 1 and Figure 2 The cylindrical body 51 is a cylindrical body with a rounded rectangular shape in horizontal cross section and has an opening. The cylindrical body 51 is embedded in the top 20a of the chamber 20 with its opening facing away from the turntable 31 and protrudes toward the inner space of the chamber 20. The cylindrical body 51 is made of the same material as the turntable 31.

[0103] The window member 52 is a flat plate of a dielectric such as quartz having a shape roughly similar to the horizontal cross-section of the cylindrical body 51. The window member 52 is provided in a manner to block the opening of the cylindrical body 51, and divides the processing space 59 in the chamber 20 into which the process gas G2 containing nitrogen is introduced and the interior of the cylindrical body 51. The window member 52 needs to suppress oxidation caused by the inflow of oxygen into the processing space 59. For example, the required oxygen concentration is very low, and is 10 19 (atom / cm 3 ) or less. To cope with this situation, a protective coating is applied to the surface of the window member 52. For example, by coating the surface of the window member 52 with Y2O3 (yttrium oxide), it is possible to suppress consumption of the window member 52 by plasma while suppressing oxygen release from the surface of the window member 52, thereby maintaining a low oxygen concentration.

[0104] The processing space 59 is formed between the rotating table 31 and the inside of the cylindrical body 51 in the nitriding treatment section 50. The workpiece 10 circulated and transported by the rotating table 31 repeatedly passes through the processing space 59, thereby undergoing nitriding treatment. The window member 52 may be a dielectric such as alumina or a semiconductor such as silicon.

[0105] The antenna 53 is a conductor wound in a coil shape, and is arranged in the inner space of the cylindrical body 51 isolated from the processing space 59 in the chamber 20 by the window member 52, and generates an electric field by flowing an alternating current. It is ideal that the antenna 53 is arranged near the window member 52 so that the electric field generated by the antenna 53 is efficiently introduced into the processing space 59 via the window member 52. The antenna 53 is connected to an RF power supply 54 that applies a high-frequency voltage. A matching box 55 as a matching circuit is connected in series on the output side of the RF power supply 54. The matching box 55 matches the impedance of the input side and the output side, thereby stabilizing the discharge of the plasma.

[0106] like Figure 2 As shown, the process gas introduction part 58 introduces the process gas G2 containing nitrogen into the processing space 59. The process gas introduction part 58 has a supply source of the process gas G2 such as a gas cylinder (not shown), a pipe 57, and a gas introduction port 56. The pipe 57 is connected to the supply source of the process gas G2, penetrates the chamber 20 while hermetically sealing the chamber 20, and extends to the inside of the chamber 20, and its end is opened as the gas introduction port 56.

[0107] The gas introduction port 56 opens into the processing space 59 between the window member 52 and the turntable 31, and introduces the process gas G2. As the process gas G2, a rare gas can be used, and argon gas or the like is suitable.

[0108] In such a nitriding treatment section 50, a high-frequency voltage is applied to the antenna 53 from the RF power supply 54. As a result, a high-frequency current flows in the antenna 53, and an electric field is generated by electromagnetic induction. The electric field is introduced into the processing space 59 via the window member 52, and an inductively coupled plasma is generated in the process gas G2. At this time, nitrogen chemical species containing nitrogen atoms are generated, and they are bonded to Ga atoms and Al atoms by colliding with the film containing Ga atoms and the film containing Al atoms on the workpiece 10. As a result, the nitrogen content of the film on the workpiece 10 can be increased, and a GaN film and an AlN film without nitrogen defects can be formed.

[0109] [Heating unit]

[0110] The heating unit 60 heats the workpiece 10 circulated and transported by the rotary table 31 in the chamber 20. The heating unit 60 has a heating source provided at a position of the rotary table 31 facing the transport path L of the workpiece 10. The heating source is, for example, a halogen lamp. The heating temperature is preferably set to a temperature at which the workpiece 10 is heated to about 500°C.

[0111] [Transfer Room]

[0112] The transfer chamber 70 is a container for transferring the workpiece 10 into and out of the chamber 20 via a gate valve. Figure 1 As shown, the transfer chamber 70 has an internal space for accommodating the workpiece 10 before being carried into the chamber 20. The transfer chamber 70 is connected to the chamber 20 via a gate valve GV1. Although not shown, a conveying member is provided in the internal space of the transfer chamber 70, and the conveying member is used to carry the tray 34 carrying the workpiece 10 into and out of the chamber 20. The transfer chamber 70 is decompressed by an exhaust member such as a vacuum pump (not shown), and the tray 34 carrying the unprocessed workpiece 10 is carried into the chamber 20 and the tray 34 carrying the processed workpiece 10 is carried out from the chamber 20 while maintaining the vacuum of the chamber 20 by using the conveying member.

[0113] The transfer chamber 70 is connected to a load lock unit 71 via a gate valve GV2. The load lock unit 71 is a device that carries a tray 34 carrying unprocessed workpieces 10 into the transfer chamber 70 from the outside by a conveying member (not shown) while maintaining the vacuum of the transfer chamber 70, and carries a tray 34 carrying processed workpieces 10 out of the transfer chamber 70. The load lock unit 71 switches between a vacuum state in which the pressure is reduced by an exhaust member such as a vacuum pump (not shown) and an atmospheric open state in which the vacuum is broken.

[0114] [Preparatory heating chamber]

[0115] The preliminary heating chamber 80 heats the workpiece 10 before it is carried into the chamber 20. The preliminary heating chamber 80 includes a container connected to the transfer chamber 70, and has a heating source for heating the workpiece 10 before it is carried into the transfer chamber 70. As the heating source, for example, a heater or a heating lamp is used. As the preliminary heating temperature, it is preferred that the workpiece 10 is heated to a temperature of about 300° C. In addition, the conveyance of the tray 34 between the preliminary heating chamber 80 and the transfer chamber 70 is performed by a conveying member not shown in the figure.

[0116] [Cooling room]

[0117] The cooling chamber 90 cools the workpiece 10 moved out of the chamber 20. The cooling chamber 90 includes a container connected to the transfer chamber 70, and has a cooling component that cools the workpiece 10 carried on the tray 34 moved out of the transfer chamber 70. As the cooling component, for example, a blowing portion that blows a cooling gas can be used. The cooling gas can use, for example, Ar gas from a supply source of the sputtering gas G1. As the temperature to be cooled, it is preferably set to a temperature that can be transported in the atmosphere, for example, 30°C. Furthermore, the tray 34 of the transfer chamber 70 carrying the processed workpiece 10 is moved into the cooling chamber 90 by a transport component not shown.

[0118] [Control device]

[0119] The control device 100 controls various elements constituting the film forming apparatus 1, such as the exhaust unit 23, the sputtering gas introduction unit 49, the process gas introduction unit 58, the power supply unit 46, the RF power supply 54, the conveying unit 30, the heating unit 60, the transfer chamber 70, the load lock unit 71, the preheating chamber 80, and the cooling chamber 90. The control device 100 is a processing device including a programmable logic controller (PLC) or a central processing unit (CPU), and stores a program describing the control content.

[0120] Specific contents to be controlled include: initial exhaust pressure of the film forming device 1, power applied to the target 42 and the antenna 53, flow rate of the sputtering gas G1 and the process gas G2, introduction time and exhaust time, film forming time, rotation speed of the motor 32, etc. Thus, the control device 100 can cope with a variety of film forming specifications. In addition, the control device 100 also controls the heating temperature and heating time of the heating unit 60, the heating temperature and heating time of the preheating chamber 80, the cooling temperature and cooling temperature of the cooling chamber 90, etc.

[0121] [action]

[0122] Next, the operation of the film forming apparatus 1 controlled by the control device 100 will be described. As described below, a film forming method for forming a film using the film forming apparatus 1 is also an embodiment of the present invention. Figure 3 This is a flow chart of a film forming process performed using the film forming device 1 of the present embodiment. The film forming process is a process of alternately stacking AlN films and GaN films on the workpiece 10 to form a GaN layer. The crystal lattice of a silicon wafer or a sapphire substrate is different from that of GaN, so when a GaN film is directly formed, there is a problem of decreased crystallinity of GaN. In order to eliminate this mismatch in the crystal lattice, a buffer layer is formed by alternately stacking AlN films and GaN films, and a GaN layer is formed on the buffer layer. This can be used in the following situations: For example, in the manufacture of a horizontal metal oxide semiconductor field effect transistor (MOSFET) or LED, a GaN layer is formed on a silicon wafer via a buffer layer.

[0123] First, the chamber 20 is exhausted from the exhaust port 21 through the exhaust unit 23, and the pressure is always reduced to a specified pressure. In addition, while exhausting, the heating unit 60 starts heating and the turntable 31 starts rotating, thereby heating the turntable 31 passing through the heating unit 60. The inside of the chamber 20 is heated by radiation from the heated turntable 31. By heating together with exhaust, the detachment of residual gases such as water molecules or oxygen molecules in the chamber 20 is promoted. As a result, it is difficult for residual gases to mix as impurities during film formation, and the crystallinity of the film is improved. After the oxygen concentration in the chamber 20 is detected to be below the specified value using a gas analysis device such as Q-Mass, the heating of the heating unit 60 is stopped and the rotation of the turntable 31 is stopped. In addition, in the preheating chamber 80, the workpiece 10 mounted on the tray 34 is preheated to about 300°C (step S01).

[0124] The tray 34 carrying the pre-heated workpiece 10 is carried into the transfer chamber 70 by the conveying member, and is sequentially carried into the chamber 20 via the gate valve GV1 (step S02). In the step S02, the rotating table 31 sequentially moves the empty holding parts 33 to the carrying-in position from the transfer chamber 70. The holding parts 33 each hold the tray 34 carried in by the conveying member. In this way, all the trays 34 carrying the workpiece 10 are placed on the rotating table 31.

[0125] The heating unit 60 starts heating again, and the rotating table 31 on which the workpiece 10 is placed starts rotating, thereby heating the workpiece 10 (step S03). After a predetermined time obtained in advance through simulation or experiment, the workpiece 10 is heated to about 500° C. During heating, the rotating table 31 is rotated at a relatively fast speed of about 100 rpm in order to heat more evenly.

[0126] Then, a buffer layer is formed by alternately repeating the formation of an AlN film using the Al film forming processing unit 40B and the nitriding processing unit 50, and the formation of a GaN film using the GaN film forming processing unit 40A and the nitriding processing unit 50. First, an AlN film is formed on the workpiece 10 using the Al film forming processing unit 40B and the nitriding processing unit 50 (step S04). That is, the sputtering gas inlet unit 49 supplies the sputtering gas G1 via the gas inlet port 47. The sputtering gas G1 is supplied to the vicinity of the target 42 including Al. The power supply unit 46 applies a voltage to the target 42. Thereby, the sputtering gas G1 is plasmatized. The ions generated by the plasma collide with the target 42 and knock out sputtering particles containing Al atoms.

[0127] When the unprocessed workpiece 10 passes through the Al film forming treatment section 40B, a thin film of sputtered particles containing Al atoms is formed on the surface. In this embodiment, each time the workpiece passes through the Al film forming treatment section 40B, a film thickness that can contain one to two Al atoms in the thickness direction can be deposited.

[0128] In this way, the workpiece 10 that has passed through the Al film forming processing section 40B by the rotation of the rotating table 31 passes through the nitriding processing section 50, and the Al atoms of the thin film are nitrided in the process. That is, the process gas introduction section 58 supplies the process gas G2 containing nitrogen through the gas introduction port 56. The process gas G2 containing nitrogen is supplied to the processing space 59 sandwiched by the window member 52 and the rotating table 31. The RF power supply 54 applies a high-frequency voltage to the antenna 53.

[0129] The electric field generated by the antenna 53 through which the high-frequency current flows by the application of the high-frequency voltage is introduced into the processing space 59 through the window member 52. Then, the process gas G2 containing nitrogen gas supplied to the space is excited by the electric field to generate plasma. The nitrogen chemical species generated by the plasma collide with the thin film on the workpiece 10, thereby bonding with Al atoms to form a fully nitrided AlN film.

[0130] The rotating table 31 continues to rotate until an AlN film of a predetermined thickness is formed on the workpiece 10, that is, until a predetermined time obtained in advance through simulation or experiment has passed. In other words, the workpiece 10 continues to circulate in the film forming processing unit 40 and the nitriding processing unit 50 until an AlN film of a predetermined thickness is formed. In addition, it is preferred to perform nitridation whenever Al is deposited with a film thickness at the atomic level, so in order to achieve a balance between film formation and nitridation, the rotation speed of the rotating table 31 is set to a relatively slow speed of 50 rpm to 60 rpm.

[0131] When a predetermined time has passed, the operation of the Al film forming processing unit 40B is first stopped. Specifically, the application of voltage to the target 42 by the power supply unit 46 is stopped.

[0132] Next, a GaN film is formed on the workpiece 10 by the GaN film forming unit 40A and the nitriding unit 50 (step S05). That is, the sputtering gas G1 is turned into plasma by supplying the sputtering gas G1 around the target 42 by the sputtering gas introduction unit 49 and applying a voltage to the target 42 by the power supply unit 46. The ions generated by the plasma collide with the target 42 to knock out sputtered particles containing Ga atoms.

[0133] Thus, a thin film is formed on the surface of the AlN film in which the sputtered particles containing Ga atoms are deposited. In this embodiment, each time the particles pass through the film forming processing unit 40 once, the particles can be deposited to a film thickness that can contain one to two Ga atoms.

[0134] In this way, the workpiece 10 that has passed through the GaN film forming processing section 40A by the rotation of the rotating table 31 passes through the nitriding processing section 50, and Ga atoms in the thin film are nitrided in the process. That is, as described above, the chemical species of nitrogen generated by the plasma collide with the thin film on the workpiece 10, thereby bonding with Ga atoms with defective bonding with nitrogen, and forming a GaN film without nitrogen defects.

[0135] As the time for forming a GaN film of a specified thickness on the workpiece 10, when the time obtained by simulation or experiment has passed, the rotating table 31 first stops the operation of the film forming processing unit 40. That is, when the specified time has passed, the operation of the GaN film forming processing unit 40A is stopped. Specifically, the application of voltage to the target 42 by the power supply unit 46 is stopped. The formation of the AlN film and the GaN film as described above is repeated until the specified number of stacking is reached (step S06 No). When the specified number of stacking is reached (step S06 Yes), the formation of the buffer layer is terminated.

[0136] Then, a GaN layer is formed on the buffer layer (step S07). The GaN layer is formed in the same manner as the GaN film in the buffer layer, but the film is formed within a time period to achieve a predetermined thickness set for the GaN layer.

[0137] After forming the buffer layer and the GaN layer as described above, the operation of the GaN film forming processing unit 40A is stopped as described above, and then the operation of the nitriding processing unit 50 is stopped (step S08). Specifically, the supply of high-frequency power to the antenna 53 by the RF power supply 54 is stopped. Then, the rotation of the turntable 31 is stopped, and the tray 34 carrying the film-formed workpiece 10 is moved into the cooling chamber 90 via the transfer chamber 70 by the conveying member, and after the workpiece 10 is cooled to a predetermined temperature, it is discharged from the load lock unit 71 (step S09).

[0138] Furthermore, in the above description, the nitridation treatment unit 50 is continuously operated during the film formation of the buffer layer (step S04 to step S06), but the operation of the nitridation treatment unit 50 may be stopped each time each step of step S04 to step S06 is completed. In this case, after the operation of the Al film forming treatment unit 40B and the GaN film forming treatment unit 40A is stopped, the operation of the nitridation treatment unit 50 is stopped. Thus, the surface of the film formed on the workpiece 10 can also be fully nitrided, and an AlN film and a GaN film without nitrogen defects can be obtained.

[0139] [Effect]

[0140] (1) The film forming device 1 of the present embodiment includes: a chamber 20 capable of making the interior of the chamber 20 a vacuum; a turntable 31 disposed in the chamber 20, holding the workpiece 10, and cyclically transporting the workpiece 10 in a circular trajectory; a GaN film forming processing section 40A, having a target containing a film forming material containing GaN, and a plasma generator for plasma-forming a sputtering gas G1 introduced between the target 42 and the turntable 31, so that particles of the film forming material containing GaN are deposited on the workpiece 10 cyclically transported by the turntable 31 by sputtering; and a nitriding processing section 50, which nitrides the particles of the film forming material deposited in the GaN film forming processing section 40A on the workpiece 10 cyclically transported by the turntable 31.

[0141] The film forming method of this embodiment is to hold the workpiece 10 by a turntable 31 in a chamber 20 capable of making the interior of the chamber 20 vacuum and circulate it in a circular trajectory, and at the same time, film is formed on the workpiece 10, and the film forming method includes: GaN film forming treatment, the GaN film forming treatment unit 40A deposits particles of a film forming material containing GaN on the workpiece 10 circulated and transported by the turntable 31 by sputtering, the GaN film forming treatment having a target 42 containing a film forming material containing GaN, and a plasma generator for plasmatizing a sputtering gas G1 introduced between the target 42 and the turntable 31; and nitridation treatment, the nitridation treatment unit 50 nitridates particles of the film forming material deposited in the GaN film forming treatment unit 40A on the workpiece 10 circulated and transported by the turntable 31.

[0142] In this embodiment, in the chamber 20, the workpiece 10 circulated and transported by the rotating table 31 is subjected to film formation by sputtering, thereby forming a GaN film with high productivity. That is, there is no need to use a large amount of NH3 gas as in the MO-CVD method. The sputtering gas G1 and the process gas G2 flow in a limited area in the vacuum chamber 20, so that the material of the target 42 is deposited and nitrided with a film thickness at the atomic level, so the use efficiency of the material is high. In addition, since a reaction gas containing hydrogen (H) is not used, no unnecessary processes such as dehydrogenation are required. In addition, it is sufficient to introduce a rare gas that is easy to handle into the chamber 20, so it is easy to stably maintain the state of the device, and the yield becomes good. The heating temperature is also a relatively low temperature, which is about 500°C, so the output required by the heating device is also low. A series of film forming processes of the buffer layer and the GaN layer are completed in the chamber 20, so other layers are formed in different chambers in the middle of a series of film formations, so there is no need to move between chambers, and film formation can be performed in an environment with a similarly low oxygen concentration.

[0143] Furthermore, since the stacking and nitridation of film-forming materials with a film thickness at the atomic level are repeated, a film with high crystallinity and less surface irregularities can be formed despite a shorter film-forming time than the MO-CVD method.

[0144] Here, the results of evaluating films formed under the following film forming conditions are shown.

[0145] Workpiece: Si (111) substrate

[0146] Rotating table speed: 60rpm

[0147] · High frequency power applied to antenna (nitriding treatment part): 4000W

[0148] · DC power applied to the sputtering source: 800W to 1500W for the GaN film forming processing unit, 2000W to 3500W for the Al film forming processing unit (in a film forming processing unit including two sputtering sources, the power applied to each sputtering source)

[0149] Film formation rate: GaN layer 0.28nm / sec AlN layer 0.43nm / sec

[0150] Ar gas flow rate in film forming process: GaN film forming process 80 sccm Al film forming process 45 sccm

[0151] ·N2 gas flow rate of nitriding treatment unit: 30sccm

[0152] In addition, in the above-mentioned embodiment, heating is not performed during film formation.

[0153] X-ray diffraction analysis was performed on the AlN film 3μm (No. 1), GaN film 3μm (No. 2), 30-layer stacked film of AlN film 5nm / GaN film 5nm (No. 3), and stacked film of GaN film 3μm stacked on 30-layer stacked film of AlN film 5nm / GaN film 5nm (No. 4). As a result, the half-value width (°) of the rocking curve obtained by 2θ / ω scanning of the (002) plane on the film surface showed that No. 1 was 0.246, No. 2 was 0.182, No. 3 was 0.178, and No. 4 was 0.197.

[0154] Generally speaking, it can be said that the smaller the half-value width, the smaller the deviation of the crystal orientation, and the higher the crystallinity. In this embodiment, a highly crystalline film with a half-value width (2θ / ω) of less than 0.2° can be formed. In addition, the film thickness of the GaN buffer layer used in GaN-based devices is generally set to 3μm to 10μm, but the film formation rate of the MO-CVD method is said to be several μm / h. The film formation rate of this embodiment is at the same level, but the hydrogen desorption process can be omitted, so the film formation time can be shortened compared to the MO-CVD method. In addition, compared with the MO-CVD method, even low-temperature film formation can obtain a highly crystalline film.

[0155] Furthermore, if the solid target 42 contains a lot of nitrogen, there is a problem that the surface becomes an insulator, so that the target 42 cannot contain a lot of nitrogen, and contains Ga atoms with bonding defects with nitrogen. If such a target 42 is used for sputtering, a GaN film with nitrogen defects will be formed. However, in the present embodiment, by providing a nitridation treatment section 50 independently from the GaN film forming treatment section 40A, even if the target 42 contains Ga atoms with bonding defects with nitrogen, a GaN film without nitrogen defects can be obtained by increasing the nitrogen content through the nitridation treatment section 50. In addition, in the GaN film forming treatment section 40A, nitrogen is not used, and the sputtering gas G1 can be used as a single argon gas, and the particles of the film forming material deposited on the workpiece 10 are nitrided by the nitridation treatment section 50 separated from the GaN film forming treatment section 40A. Therefore, the surface of the target 42 will not become an insulator, and DC discharge can be used to increase the film forming rate.

[0156] (2) The film forming device 1 has an Al film forming processing unit 40B, wherein the Al film forming processing unit 40B has a target 42 containing a film forming material containing Al, and particles of the film forming material containing Al are deposited on the workpiece 10 circulated and transported by the turntable 31 through sputtering, and the nitriding processing unit 50 nitrides the particles of the film forming material deposited in the Al film forming processing unit 40B on the workpiece 10 circulated and transported by the turntable 31.

[0157] Therefore, for example, when using a workpiece 10 having a crystal lattice different from that of GaN, such as silicon, a buffer layer is formed by alternately stacking GaN films and AlN films using the GaN film forming processing unit 40A, the Al film forming processing unit 40B and the nitridation processing unit 50, thereby suppressing the decrease in the crystallinity of the GaN layer.

[0158] In addition, after forming the buffer layer, the GaN layer can be formed without being exposed to the atmosphere, so that the surface of the buffer layer is inhibited from being degraded, and the GaN layer formed on the buffer layer can be prevented from being degraded. In addition, there is no need to move to an environment different from the film formation environment of the buffer layer in order to form the GaN layer, and there is no need to reduce the transport time or set up a separate space with adjusted oxygen concentration, etc.

[0159] In addition, in the Al film forming processing section 40B, nitrogen gas is not used either, but the sputtering gas G1 can be made into a single argon gas, and the particles of the film forming material deposited on the workpiece 10 can be nitrided by the nitriding processing section 50 separated from the Al film forming processing section 40B. Therefore, the surface of the target 42 does not become an insulator, and the film forming rate can be increased by using DC discharge.

[0160] (3) The film forming apparatus 1 includes the heating unit 60 for heating the workpiece 10 circulated and transported by the turntable 31. This allows the formation of a film with better crystallinity.

[0161] (4) The film forming apparatus 1 further includes the preheating chamber 80 for heating the workpiece 10 before being carried into the chamber 20. By preheating the workpiece 10 in the preheating chamber 80, the heating time by the heating unit 60 can be shortened, thereby improving productivity.

[0162] [Modifications]

[0163] (1) In the embodiment described above, Figure 4As shown, an impurity addition treatment section may be provided for adding n-type or p-type impurities (dopants) to the formed GaN film. In this case, the GaN film forming treatment section, the nitridation treatment section, and the impurity addition treatment section are arranged in the order of the GaN film forming treatment section, the nitridation treatment section, and the impurity addition treatment section on the circulation conveying path. The impurity addition treatment section includes the same structure as the film forming treatment section of the film forming treatment section 40A and the film forming treatment section 40B. More specifically, the impurity addition treatment section only needs to be as follows: it includes a target and a plasma generator, the target includes a film forming material containing n-type impurities or p-type impurities, and the impurity addition treatment section can add particles of the film forming material containing ions that become impurities (sputtered particles) to the film deposited on the workpiece 10 by sputtering the target. For example, the Mg film forming treatment section 40C having a target 42 containing a film forming material containing Mg and the Si film forming treatment section 40D having a target 42 containing a film forming material containing Si can be used as impurity addition treatment sections. The Mg film forming processing unit 40C and the Si film forming processing unit 40D also have the same structure as the GaN film forming processing unit 40A except for the material of the target 42. That is, the Mg film forming processing unit 40C and the Si film forming processing unit 40D include: a sputtering source including a target 42, a support plate 43 and an electrode 44; and a plasma generator including a power supply unit 46 and a sputtering gas introduction unit 49.

[0164] In this embodiment, when forming a GaN film, the Mg film forming processing unit 40C is operated together with the GaN film forming processing unit 40A and the nitriding processing unit 50, thereby forming a layer including a p-channel (p-type semiconductor) in which Mg ions are added to the GaN layer. In addition, when forming a GaN film, the Si film forming processing unit 40D is operated together with the GaN film forming processing unit 40A and the nitriding processing unit 50, thereby forming a layer including an n-channel (n-type semiconductor) in which Si ions are added to the GaN layer.

[0165] In order to form an n-channel and a p-channel, previously, after the GaN film is formed, Mg or Si ions are injected by an ion beam or other ion implantation device, and added by heat treatment. However, in this method, since ion implantation is performed on a film having a predetermined film thickness, the implantation depth and implantation amount (dose) are sometimes different from the designed values ​​and are not easy to control. According to this embodiment, the deposition of the GaN film and the addition of Si ions or Mg ions are repeated alternately until the GaN film reaches a predetermined film thickness. Thus, according to the power applied to the target 42 and the rotation speed of the rotating table 31, it becomes easy to control the implantation depth and implantation amount of the Mg ions or Si ions corresponding to the film thickness of the GaN layer formed each time the film is rotated.

[0166] In addition, a series of film formations of a buffer layer, a GaN layer, a layer including an n-channel, and a layer including a p-channel can be performed in one chamber 20. Therefore, it is not necessary to move to an environment different from the film formation environment of the GaN layer in order to form an n-channel or a p-channel, and it is not necessary to reduce the transport time or to set up a separate space with adjusted oxygen concentration.

[0167] (2) In addition to the above embodiments, Figure 5 As shown, as the film forming processing unit 40, an InN film forming processing unit 40E may be provided, and the InN film forming processing unit 40E has a target 42 containing a film forming material containing InN. Indium (In) alone has a low melting point, and in order to actually make a solid target 42, an InN target to which nitrogen (N) is added is used. The InN target contains In atoms that are insufficiently bonded to nitrogen, which is the same as described above.

[0168] In this embodiment, when forming a GaN film, the InN film forming processing unit 40E is operated together with the GaN film forming processing unit 40A and the nitriding processing unit 50, thereby forming an InGaN film. Figure 6 As shown in (A), the InGaN film functions as the light-emitting layer 14 of the LED. Figure 6 (A) shows the stacked structure of the LED, where a buffer layer 11, a GaN layer 12 including an n-channel, a buffer layer 11, a GaN layer 13 including a p-channel, a light-emitting layer 14, and a transparent conductive film 15 are stacked on a silicon workpiece 10. The transparent conductive film 15 is an indium tin oxide (ITO) film. The electrodes are not shown in the figure. In addition, Figure 6 (B) represents the buffer layer 11 .

[0169] In this embodiment, a series of film formation of the buffer layer 11, the GaN layer 12 containing the n-channel, the buffer layer 11, the GaN layer 13 containing the p-channel, and the light-emitting layer 14 in the LED can be performed in one chamber 20. Therefore, there is no need to move to an environment different from the film formation environment of the GaN layer in order to form the light-emitting layer 14, and the transportation time can be reduced. Alternatively, there is no need to set up a separate space in which the oxygen concentration is adjusted. Furthermore, the color can be changed according to the thickness of the light-emitting layer 14, but in the embodiment described above, the thickness is easily controlled, so it is easy to make light-emitting layers 14 of different colors.

[0170] (3) The power supplies used in the film forming processing units that form films of different types of materials may also be set to different types of power supplies. For example, the power supply used in one of the film forming processing units may be set to a DC power supply, and the power supply used in the other film forming processing unit may be set to a pulse power supply including a pulse switch. In this case, when the Mg ions are added, the power supply used in the GaN film forming processing unit 40A may be set to a DC power supply, and the power supply used in the Mg film forming processing unit 40C may be set to a pulse power supply. Or when Si ions are added, the power supply used in the GaN film forming processing unit 40A may be set to a DC power supply, and the power supply used in the Si film forming processing unit 40D may be set to a pulse power supply. In particular, by setting the pulse width and power in a manner that a large power based on a pulse wave is turned on in a short period of time to perform high-power pulse magnetron sputtering (HiPIMS), a high-density plasma is generated, and the ionization rate of the sputtered particles is dramatically increased, thereby enabling more efficient particle injection.

[0171] Alternatively, the power supply used in the film forming processing unit for forming a film of the same type of material may be a combination of different types of power supplies, and switched at a specified time. For example, a DC power supply and a pulse power supply including a pulse switch may be used, and switched at a specified time. In this case, when forming a GaN film, a pulse power supply may be used only in the initial layer that is in contact with the substrate or other types of films, and after forming a specified film thickness, the film formation may be switched to using a DC power supply.

[0172] [Other embodiments]

[0173] Although the embodiments of the present invention and the variations of each part are described, the embodiments or the variations of each part are provided as an example and are not intended to limit the scope of the invention. The novel embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or their variations are included in the scope or the main idea of ​​the invention, and are included in the invention described in the claims.

[0174] In addition, the type or number of the film forming processing unit 40 and the number of the nitriding processing unit 50 provided in the chamber 20 are not limited to the above-described embodiment. The film forming processing unit 40 may be provided as only the GaN film forming processing unit 40A to constitute the film forming apparatus 1 for forming a GaN film. In addition, in addition to the above-described film forming processing unit 40, a film forming processing unit 40 using a target of a different type may be added, or a film forming processing unit using a target of the same type may be added, or a nitriding processing unit 50 may be added. For example, a film forming processing unit 40 having a target 42 containing indium oxide and tin oxide that are ITO film forming materials may be added to form an ITO film in the chamber 20. In this case, oxygen may be introduced into the nitriding processing unit 50 instead of nitrogen to compensate for the oxidation of the ITO film. In addition, for example, the GaN film forming processing unit 40A, the Al film forming processing unit 40B, and the nitriding processing unit 50 may be operated simultaneously to form an AlGaN (Aluminum Gallium Nitride) film containing Ga, Al, and N.

[0175] In addition, the n-type impurities or p-type impurities added in the impurity addition processing unit are not limited to the above-described embodiments. For example, Ge or Sn can also be listed as n-type impurities. In this case, the film-forming material constituting the target provided in the impurity addition processing unit can be a film-forming material containing Ge or Sn instead of Si.

Claims

1. A film forming device, characterized in that: include: A chamber capable of making the interior a vacuum; A rotating table is disposed in the chamber, holds the workpiece, and cyclically transports the workpiece in a circular trajectory; A GaN film forming processing section having a target containing a film forming material containing GaN and a plasma generator for converting a sputtering gas introduced between the target and the turntable into plasma, so that particles of the film forming material containing GaN are deposited on the workpiece circulated and transported by the turntable by sputtering; a nitriding treatment section for nitriding particles of the film forming material deposited on the workpiece circulated and transported by the turntable in the GaN film forming treatment section; as well as An impurity addition processing section includes a target containing a film-forming material containing p-type impurities or n-type impurities, and a plasma generator for converting a sputtering gas introduced between the target containing the film-forming material containing p-type impurities or n-type impurities and the rotating table into plasma, and adding n-type impurities or p-type impurities to particles of the film-forming material containing GaN deposited on the workpiece in the GaN film-forming processing section by sputtering, The GaN film forming processing section, the nitridation processing section and the impurity adding processing section are arranged on the circular conveying path, and the turntable causes the workpiece to repeatedly pass through the GaN film forming processing section, the nitridation processing section and the impurity adding processing section in sequence, thereby conveying the workpiece in a manner of repeating the film forming, nitridation and impurity adding of the GaN film, thereby forming a specified number of stacked GaN films containing the n-type impurities or the p-type impurities on the workpiece.

2. The film forming device according to claim 1, characterized in that The sputtering gas is a single gas of argon.

3. The film forming device according to claim 1 or 2, characterized in that An Al film forming processing unit is provided, wherein the Al film forming processing unit has a target including a film forming material containing Al, and particles of the film forming material containing Al are deposited on the workpiece circulated and transported by the turntable by sputtering. The nitriding treatment section nitridates particles of the film forming material deposited on the workpiece circulated and transported by the turntable in the Al film forming treatment section.

4. The film forming device according to claim 3, characterized in that The GaN film forming processing part, the Al film forming processing part, and the nitridation processing part form a film in which GaN films and AlN films are alternately stacked.

5. The film forming device according to claim 1, characterized in that The impurity addition processing section is a Mg film forming processing section having a target containing a film forming material containing Mg, and depositing particles of the film forming material containing Mg on the workpiece circulated and transported by the turntable by sputtering. The GaN film forming processing unit, the nitriding processing unit, and the Mg film forming processing unit form a film in which Mg is added to GaN.

6. The film forming device according to claim 1, characterized in that The impurity addition processing section is a Si film forming processing section having a target containing a film forming material containing Si, and depositing particles of the film forming material containing Si on the workpiece circulated and transported by the turntable by sputtering. The GaN film forming processing unit, the nitriding processing unit, and the Si film forming processing unit form a film in which Si is added to GaN.

7. The film forming device according to claim 1, characterized in that An InN film forming processing unit is provided, wherein the InN film forming processing unit has a target containing a film forming material containing InN, and particles of the film forming material containing InN are deposited on the workpiece circulated and transported by the turntable by sputtering. The GaN film forming processing unit, the nitridation processing unit, and the InN film forming processing unit form an InGaN film.

8. The film forming device according to claim 1, characterized in that A heating unit is provided for heating the workpiece circulated and conveyed by the turntable.

9. The film forming device according to claim 8, characterized in that The invention further includes a preliminary heating chamber for heating the workpiece before the workpiece is carried into the chamber.

10. The film forming device according to claim 1, characterized in that The power applied to the impurity addition processing section is applied by a pulse power supply.

11. A film forming method, in a chamber capable of being made vacuum, wherein a workpiece is held by a rotating table and cyclically transported in a circular trajectory, while a film is formed on the workpiece, wherein the film forming method is characterized by comprising: GaN film forming process, wherein the GaN film forming process section deposits particles of a film forming material containing GaN on the workpiece circulated and transported by the turntable by sputtering, and the GaN film forming process section comprises a target containing a film forming material containing GaN, and a plasma generator for converting a sputtering gas introduced between the target and the turntable into plasma; A nitridation treatment, wherein the nitridation treatment section nitridates particles of the film forming material deposited on the workpiece circulated and transported by the turntable in the GaN film forming treatment section; as well as an impurity addition process of adding n-type impurities or p-type impurities to particles of a film-forming material containing GaN deposited on the workpiece in the GaN film-forming process section by sputtering, The workpiece is circulated and transported, and the GaN film forming process, the nitridation process, and the impurity adding process are sequentially repeated to form a predetermined number of stacked GaN films containing the n-type impurity or the p-type impurity on the workpiece.

Images