JP5156041B2 - Thin film formation method - Google Patents

Description

  The present invention relates to a thin film forming method for manufacturing a thin film used for an optical thin film, an optical device, an optoelectronic device, a semiconductor device, and the like, and more particularly, to a thin film forming method provided with plasma generating means.

  Conventionally, plasma processing such as formation of a thin film on a substrate, surface modification of the formed thin film, etching, and the like has been performed using a reactive gas that has been converted into plasma in a vacuum vessel. For example, a thin film made of an incomplete reaction product of metal is formed on a substrate using sputtering technology, and a reactive gas made into plasma is brought into contact with the thin film made of this incomplete reaction product to form a thin film made of a metal compound. A technique is known (for example, Patent Document 1).

  In this technique, a plasma generating means is used to turn reactive gas into plasma in a vacuum vessel of a thin film forming apparatus. The gas converted into plasma by the plasma generating means includes ions, electrons, atoms, molecules, and active species (radicals, excited radicals, etc.). Electrons and ions contained in the plasma gas may damage the thin film, while radicals of an electrically neutral reactive gas often contribute to the formation of the thin film. For this reason, in this conventional technique, a grid is used to prevent electrons and ions from moving toward the thin film on the substrate and to selectively bring radicals into contact with the thin film. As described above, by using the grid, the relative density in the plasma gas of radicals that contribute to the formation of the thin film is improved, thereby improving the efficiency of the plasma processing.

By the way, as a plasma generating means for generating plasma, devices of a parallel plate type, an ECR type, an inductive coupling type and the like have been conventionally known. Cylindrical and flat plate devices are known as inductive coupling devices (for example, Patent Document 2).
FIG. 7 is a view for explaining a conventional plasma generating means 380 of a flat plate type. FIG. 7A is a cross-sectional view showing a part of the thin film forming apparatus. As shown in FIG. 7A, the flat plate-type conventional plasma generating means 380 is configured such that a part of the vacuum vessel 311 is composed of a dielectric plate 383 made of a dielectric material such as quartz, and the atmosphere of the dielectric plate 383 is changed. The antenna 385 is disposed along the outer wall located on the side. That is, the antenna 385 is provided outside the vacuum vessel 311, in other words, in the atmosphere. FIG. 7B shows the shape of the antenna 385. The antenna 385 is spiral in the same plane. The flat plate type conventional plasma generator 380 generates plasma in the vacuum chamber 111 by applying power of a frequency of 100 kHz to 50 MHz by a high frequency power source 389 through a matching box 387 provided with a matching circuit in the antenna 385. It is. Application of high-frequency power to the antenna 385 is performed via a matching circuit for performing impedance matching, as indicated by a matching box 387 in FIG. As shown in FIG. 7, the matching circuit connected between the antenna 385 and the high-frequency power source 389 includes variable capacitors 387a and 387b and a matching coil 387c.

Japanese Patent Laid-Open No. 2001-234338 (pages 2, 10, 11 and FIGS. 1 and 2) JP-A-8-83696 (page 4-6, FIGS. 1 and 8)

When forming a film using the flat plate type conventional plasma generating means 380 in a thin film forming apparatus, the pressure during the film formation in the vacuum vessel 311 forming the space for forming the thin film is approximately 10 ¹ to 10 ⁻² Pa. Retained. Since the atmosphere is approximately 10 ⁵ Pa, a large pressure difference is generated between the outside and inside of the vacuum vessel 311 during film formation. Therefore, it is necessary to design the strength of the dielectric plate 383 so that it can sufficiently withstand this pressure difference. For example, it was necessary to use high-quality quartz glass with few bubbles and cracks. High quality quartz glass is expensive and expensive. Further, when quartz glass is used as the dielectric plate 383, a thickness of several tens of millimeters is required to withstand the pressure difference described above. As described above, when the dielectric plate 383 is made thick, it is necessary to supply a large electric power to the antenna 385 in order to generate plasma having a necessary density in the vacuum vessel 311, and the thickness of the dielectric plate 383 is increased. There is a problem that the distance between the antenna 385 and the inside of the vacuum vessel 311 increases by the amount, and the generation of plasma becomes inefficient. In addition, since the antenna 385 is exposed to the atmosphere, it is easily oxidized, and there is a problem that maintenance work is required and the life of the antenna is shortened.

  Although a thin film forming apparatus using a plasma generating means in which the antenna is placed in a space for forming a thin film in a vacuum vessel, not in the atmosphere, is also used, but the antenna is placed in a space for forming a thin film. The antenna material is mixed into the thin film, and the antenna surface is contaminated, resulting in instability of the plasma.

  In view of the above problems, an object of the present invention is to provide a thin film forming method capable of forming a film by generating stable plasma with high efficiency.

In order to solve the above-mentioned problem, a thin film forming method according to claim 1 includes a vacuum container that maintains a vacuum inside, and a plasma generating means that is connected to the vacuum container and generates plasma in the vacuum container. The plasma generating means includes a dielectric wall formed of a dielectric, an antenna installed adjacent to the dielectric wall, and an antenna housing chamber for housing the antenna together with the dielectric wall. And a decompression means for evacuating the antenna accommodating chamber to a vacuum state, and the interior of the vacuum container and the interior of the antenna accommodating chamber are partitioned by the dielectric wall to form an independent space. formed with and the antenna housing chamber is a thin film forming method for forming a thin film using the thin film forming apparatus is maintained at a vacuum of 10 -3 ^Pa or less lower than the vacuum chamber With the interior of the vacuum vessel is evacuated, pressure reduction step and the vacuum by applying a high frequency voltage to the antenna for reducing the pressure inside of the antenna housing chamber in a vacuum state of 10 -3 ^Pa or less lower than the vacuum chamber A thin film is formed by a step of generating plasma in the container and plasma-treating the thin film formed in the vacuum container.

  By such a method, the oxidation of the antenna can be prevented and the generation of plasma in the accommodation chamber can be suppressed.

  At this time, in the decompression step, it is preferable to reduce a pressure difference between the antenna housing chamber and the vacuum vessel. If it does in this way, the dielectric wall which partitions off the inside of a vacuum vessel and an antenna storage chamber can be made comparatively thin.

Further, in the depressurization step, the inside of the vacuum vessel and the inside of the antenna housing chamber are simultaneously evacuated, and the inside of the vacuum vessel is depressurized to 10 ⁻² Pa to 10 Pa. It is preferable to reduce the pressure to ^-3 Pa or less.

  According to the method for forming a thin film of the present invention, it is possible to prevent the antenna from being oxidized and to suppress the generation of plasma in the antenna housing chamber, so that stable plasma can be generated efficiently.

  In addition, the antenna housing chamber is depressurized from the vacuum container, and at the same time, the pressure difference between the inside of the vacuum container and the antenna housing chamber is prevented from increasing, so that the antenna is prevented from being oxidized and plasma is generated in the antenna housing chamber. Since the generation of stable plasma can be suppressed and the difference in pressure between the inside of the vacuum vessel and the antenna housing chamber is small, the inside of the vacuum vessel The dielectric wall that partitions the antenna housing chamber can be made relatively thin.

It is explanatory drawing of the upper surface which took the partial cross section explaining the thin film forming apparatus used for this invention. It is explanatory drawing of the side which took the partial cross section explaining the thin film forming apparatus used for this invention. It is principal part explanatory drawing explaining the plasma generation means of this invention. It is principal part explanatory drawing explaining the plasma generation means of this invention. It is principal part explanatory drawing explaining other embodiment of a plasma generation means. It is principal part explanatory drawing explaining other embodiment of a plasma generation means. It is a figure explaining the flat plate type conventional plasma generation means.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The members, arrangements, and the like described below are not intended to limit the present invention and can be variously modified within the scope of the gist of the present invention.

  1 to 4 are explanatory diagrams for explaining the sputtering apparatus 1. FIG. 1 is an explanatory view of the upper surface of the sputtering apparatus 1 taking a partial cross-section for easy understanding, and FIG. 2 is an explanatory view of a side surface taking a partial cross-section along the line ABC in FIG. It is. FIG. 3 is a main part explanatory view for explaining the plasma generating means of the present invention. 4 is a cross-sectional view taken along the line DD of FIG. The sputtering apparatus 1 is an example of the thin film forming method of the present invention.

  In the present embodiment, the sputtering apparatus 1 that performs magnetron sputtering, which is an example of sputtering, is used. However, the present invention is not limited to this, and sputtering that performs other known sputtering such as bipolar sputtering that does not use magnetron discharge is used. An apparatus can also be used.

  According to the sputtering apparatus 1 of the present embodiment, a thin film having a target film thickness can be formed on a substrate by repeatedly forming a thin film that is considerably thinner than the target film thickness by sputtering and performing plasma treatment. In this embodiment, by repeating the process of forming a thin film having an average thickness of 0.01 to 1.5 nm by sputtering and plasma treatment, a target thin film having a thickness of about several nm to several hundred nm is formed. .

  The sputtering apparatus 1 of this embodiment includes a vacuum vessel 11, a substrate holder 13 for holding a substrate on which a thin film is to be formed, a motor 17 for driving the substrate holder 13, a partition wall 12, 16, magnetron sputtering electrodes 21 a and 21 b, an intermediate frequency AC power source 23, and plasma generation means 80 for generating plasma are the main components.

The vacuum vessel 11 is a hollow body that is made of stainless steel and is generally used in a known sputtering apparatus and has a substantially rectangular parallelepiped shape. The shape of the vacuum vessel 11 may be a hollow cylindrical shape.
The substrate holder 13 is disposed substantially at the center in the vacuum vessel 11. The shape of the substrate holder 13 is cylindrical, and a plurality of substrates (not shown) are held on its outer peripheral surface. In addition, the shape of the substrate holder 13 may not be a cylindrical shape, but may be a hollow polygonal column shape or a conical shape. The substrate holder 13 is electrically insulated from the vacuum vessel 11. As a result, abnormal discharge in the substrate can be prevented. The substrate holder 13 is disposed in the vacuum container 11 such that the central axis Z (see FIG. 2) in the cylindrical direction of the cylinder is in the vertical direction of the vacuum container 11. The substrate holder 13 is driven to rotate about the central axis Z by a motor 17 provided on the upper portion of the vacuum vessel 11 while maintaining the vacuum state in the vacuum vessel 11.

  A large number of substrates (not shown) are held on the outer peripheral surface of the substrate holder 13 in a state of being aligned while maintaining a predetermined interval in the direction (vertical direction) along the central axis Z of the substrate holder 13. In the present embodiment, the substrate is held by the substrate holder so that the surface on which the thin film of the substrate is formed (hereinafter referred to as “film formation surface”) is oriented in a direction perpendicular to the central axis Z of the substrate holder 13.

  The partition walls 12 and 16 are provided upright from the inner wall surface of the vacuum vessel 11 toward the substrate holder 13. The partition walls 12 and 16 in the present embodiment are stainless steel members having a cylindrical substantially rectangular parallelepiped shape in which a pair of facing surfaces are open. The partition walls 12 and 16 are fixed between the side inner wall of the vacuum vessel 11 and the substrate holder 13 in a state of standing from the side wall of the vacuum vessel 11 toward the substrate holder 13. At this time, the partition walls 12 and 16 are fixed so that one side of the partition walls 12 and 16 opened faces the inner wall side of the vacuum vessel 11 and the other side faces the substrate holder 13. Moreover, the edge part located in the substrate holder 13 side of the partition walls 12 and 16 has a shape along the outer periphery shape of a substrate holder.

  A film forming process zone 20 for performing sputtering is formed by being surrounded by the inner wall surface of the vacuum vessel 11, the partition wall 12, and the outer peripheral surface of the substrate holder 13. Further, a reaction for generating plasma and performing plasma processing on the thin film on the substrate surrounded by the inner wall surface of the vacuum vessel 11, the plasma generating means 80, the partition wall 16, and the outer peripheral surface of the substrate holder 13, which will be described later. A process zone 60 is formed. In this embodiment, the partition wall 16 is fixed at a position rotated about 90 degrees around the central axis Z of the substrate holder 13 from the position where the partition wall 12 of the vacuum vessel 11 is fixed. For this reason, the film forming process zone 20 and the reaction process zone 60 are formed at positions shifted by about 90 degrees with respect to the central axis Z of the substrate holder 13. Therefore, when the substrate holder 13 is rotationally driven by the motor 17, the substrate held on the outer peripheral surface of the substrate holder 13 is between the position facing the film forming process zone 20 and the position facing the reaction process zone 60. Will be transported. An exhaust pipe 15a is connected to a position between the film forming process zone 20 and the reaction process zone 60 of the vacuum container 11, and a vacuum pump 15 for exhausting the inside of the vacuum container 11 is connected to this pipe. ing.

  The wall surface of the partition wall 16 facing the reaction process zone 60 is covered with a protective layer P made of pyrolytic boron nitride (Pyrolytic Boron Nitride). Further, a protective layer P made of pyrolytic boron nitride is also coated on the inner wall surface of the vacuum vessel 11 facing the reaction process zone 60. The pyrolytic boron nitride is coated on the partition wall 16 and the inner wall surface of the vacuum vessel 11 by a pyrolysis method using a chemical vapor deposition method.

  Mass flow controllers 25 and 26 are connected to the film forming process zone 20 via pipes. The mass flow controller 25 is connected to a sputtering gas cylinder 27 that stores an inert gas. The mass flow controller 26 is connected to a reactive gas cylinder 28 that stores a reactive gas. The inert gas and the reactive gas are controlled by the mass flow controllers 25 and 26 and introduced into the film forming process zone 20. An example of the inert gas is argon gas. As the reactive gas, for example, oxygen gas, nitrogen gas, fluorine gas, ozone gas or the like can be used.

  In the film forming process zone 20, magnetron sputtering electrodes 21 a and 21 b are arranged on the wall surface of the vacuum vessel 11 so as to face the outer peripheral surface of the substrate holder 13. The magnetron sputter electrodes 21a and 21b are fixed to the vacuum vessel 11 at the ground potential via an insulating member (not shown). The magnetron sputter electrodes 21a and 21b are connected to a medium frequency AC power source 23 through a transformer 24 and configured to be able to apply an alternating electric field. The medium frequency AC power source 23 of the present embodiment applies an alternating electric field of 1 k to 100 kHz. Targets 29a and 29b are held on the magnetron sputter electrodes 21a and 21b. The shapes of the targets 29 a and 29 b are flat, and the surfaces of the targets 29 a and 29 b facing the outer peripheral surface of the substrate holder 13 are held so as to face a direction perpendicular to the central axis Z of the substrate holder 13.

  Note that a plurality of film forming process zones for performing sputtering can be provided instead of only one. That is, as shown by a broken line in FIG. 1, a film formation process zone 40 similar to the film formation process zone 20 can be provided in the vacuum container 11. For example, the partition wall 14 is provided in the vacuum vessel 11, and the film formation process zone 40 can be formed at a target position with the substrate holder 13 sandwiched between the film formation process zone 20. In the film forming process zone 40, as in the film forming process zone 20, magnetron sputtering electrodes 41 a and 41 b are arranged. The magnetron sputter electrodes 41a and 41b are connected to a medium frequency AC power source 43 through a transformer 44 so that an alternating electric field can be applied. Targets 49a and 49b are held on the magnetron sputter electrodes 41a and 41b. Mass flow controllers 45 and 46 are connected to the film forming process zone 40 via pipes. The mass flow controller 45 is connected to a sputtering gas cylinder 47 that stores an inert gas, and the mass flow controller 46 is connected to a reactive gas cylinder 48 that stores a reactive gas. An exhaust pipe is connected to a position between the film forming process zone 40 and the reaction process zone 60 of the vacuum container 11, and a vacuum pump 15 ′ for exhausting the inside of the vacuum container 11 is connected to this pipe. The The vacuum pump 15 ′ may be used in common with the vacuum pump 15.

  On the wall surface of the vacuum vessel 11 corresponding to the reaction process zone 60, an opening 11a for installing the plasma generating means 80 is formed. In addition, a reaction gas in the reactive gas cylinder 78 is introduced into the reaction process zone 60 through a pipe for introducing an inert gas in the inert gas cylinder 77 via the mass flow controller 75 and a mass flow controller 76. Piping for connecting.

The plasma generation means 80 of this embodiment will be described with reference to FIGS.
The plasma generating means 80 is provided facing the reaction process zone 60. The plasma generating means 80 of the present embodiment includes a case body 81 as a lid of the present invention, a dielectric plate 83 as a dielectric wall of the present invention, a fixing frame 84, antennas 85a and 85b, and a fixture 88. And a pipe 15a as a decompression means and a vacuum pump 15.

The case body 81 has a shape for closing the opening 11a formed on the wall surface of the vacuum vessel 11, and is fixed so as to close the opening 11a of the vacuum vessel 11 with a bolt (not shown). Since the case body 81 is fixed to the wall surface of the vacuum vessel 11, the plasma generating means 80 is connected to the vacuum vessel 11. In the present embodiment, the case body 81 is made of stainless steel. The dielectric plate 83 is formed of a plate-like dielectric. In the present embodiment, the dielectric plate 83 is made of quartz. The dielectric plate 83 may be formed of a ceramic material such as Al ₂ O ₃ instead of quartz. The fixed frame 84 is used to fix the dielectric plate 83 to the case body 81, and is a frame body having a square shape. By connecting the fixing frame 84 and the case body 81 with bolts (not shown), the dielectric plate 83 is sandwiched between the fixing frame 84 and the case body 81, and thereby the dielectric plate 83 is fixed to the case body 81. Has been. By fixing the dielectric plate 83 to the case body 81, the antenna housing chamber 80 </ b> A is formed by the case body 81 and the dielectric plate 83. That is, in this embodiment, the antenna housing chamber 80A is formed surrounded by the case body 81 and the dielectric plate 83.

  The dielectric plate 83 fixed to the case body 81 is provided facing the inside of the vacuum vessel 11 (reaction process zone 60) through the opening 11a. At this time, the antenna housing chamber 80 </ b> A is separated from the inside of the vacuum container 11. That is, the antenna accommodating chamber 80 </ b> A and the inside of the vacuum container 11 form an independent space in a state of being partitioned by the dielectric plate 83. Further, the antenna accommodating chamber 80 </ b> A and the outside of the vacuum container 11 form an independent space in a state of being partitioned by the case body 81. In the present embodiment, the antennas 85a and 85b are installed in the antenna accommodating chamber 80A formed as an independent space in this way. The antenna housing chamber 80A and the reaction process zone 60 inside the vacuum vessel 11 and the space between the antenna housing chamber 80A and the outside of the vacuum vessel 11 are kept airtight by O-rings.

  In the present embodiment, an exhaust pipe 15a is connected to the antenna accommodating chamber 80A in order to evacuate the inside of the antenna accommodating chamber 80A to make a vacuum state. A vacuum pump 15 is connected to the pipe 15a. In the present embodiment, the pipe 15 a communicates with the inside of the vacuum vessel 11. Valves V <b> 1 and V <b> 2 are provided in the pipe 15 a at positions where the vacuum pump 15 communicates with the inside of the vacuum container 11. The pipe 15a is provided with valves V1 and V3 at positions where the vacuum pump 15 communicates with the inside of the antenna housing chamber 80A. By closing either of the valves V2 and V3, gas movement between the inside of the antenna accommodating chamber 80A and the inside of the vacuum vessel 11 is prevented. The pressure inside the vacuum vessel 11 and the pressure inside the antenna housing chamber 80A are measured by a vacuum gauge (not shown).

  In the present embodiment, the sputtering apparatus 1 includes a control device (not shown). The output of the vacuum gauge is input to this control device. The control device has a function of adjusting the degree of vacuum inside the vacuum vessel 11 and inside the antenna accommodating chamber 80A by controlling the exhaust by the vacuum pump 15 based on the input measurement value of the vacuum gauge. In the present embodiment, the control device controls the opening and closing of the valves V1, V2, and V3, so that the inside of the vacuum container 11 and the inside of the antenna housing chamber 80A can be exhausted simultaneously or independently.

  The antenna 85a and the antenna 85b are used to generate plasma by receiving electric power from the high frequency power supply 89 and generating an induction electric field inside the vacuum vessel 11 (reaction process zone 60). The antennas 85a and 85b according to the present embodiment include a tubular main body portion made of copper and a covering layer made of silver covering the surface of the main body portion. In order to reduce the impedance of the antenna 85a, it is preferable to form the antennas 85a and 85b with a material having low electrical resistance. Therefore, utilizing the characteristic that high-frequency current concentrates on the surface of the antenna, the main body of the antennas 85a and 85b is formed into a circular tube with copper that is inexpensive and easy to process and has low electrical resistance, and the antennas 85a and 85b The surface of 85b is covered with silver having a lower electrical resistance than copper. With this configuration, the impedance of the antennas 85a and 85b with respect to the high frequency is reduced, and a current is efficiently passed through the antenna 85a to increase the efficiency of generating plasma.

  The antenna 85a and the antenna 85b have a vortex shape on a plane. The antenna 85a and the antenna 85b are formed on the dielectric plate 83 in a state where the vortex surface faces the reaction process zone 60 in the antenna accommodating chamber 80A formed between the case body 81 and the dielectric plate 83. Installed next to each other. In other words, the antenna 85a and the antenna 85b are perpendicular to the central axis of the vortex of the antenna 85a and the antenna 85b in a state where the vortex surface of the antenna 85a and the antenna 85b faces the wall surface of the plate-shaped dielectric plate 83. It is installed next to each other up and down. Therefore, when the motor 17 is operated to rotate the substrate holder 13 around the central axis Z, the substrate held on the outer periphery of the substrate holder faces the surface on which the film formation surface of the substrate forms the vortex of the antennas 85a and 85b. In this way, it is conveyed in the lateral direction with respect to the antennas 85a and 85b arranged vertically.

  The antenna 85 a and the antenna 85 b are connected in parallel to the high frequency power supply 89. The antennas 85a and 85b are connected to a high frequency power supply 89 through a matching box 87 that accommodates a matching circuit. As shown in FIG. 4, variable capacitors 87 a and 87 b are provided in the matching box 87. In the present embodiment, since the antenna 85b is connected in parallel to the antenna 85a, the antenna 85b plays all or part of the role played by the matching coil 387c in the conventional matching circuit (see FIG. 7). Therefore, power loss in the matching box can be reduced, and the power supplied from the high frequency power supply 89 can be effectively used for generating plasma by the antennas 85a and 85b. Also, impedance matching is easy to take.

  The spiral antennas 85a and 85b are connected to the matching box 87 via the conductor portions 86a and 86b. The conductor portions 86a and 86b are made of the same material as the antennas 85a and 85b. The case body 81 is formed with an insertion hole 81a for inserting the conductive wire portions 86a and 86b. The antennas 85a and 85b inside the antenna accommodating chamber 80A, the matching box 87 outside the antenna accommodating chamber 80A, and the high frequency power supply 89 are connected via a conducting wire portion 86a that is inserted into the insertion hole 81a. A seal member 81b is provided between the conductor portions 86a and 86b and the insertion hole 81a, and airtightness is maintained inside and outside the antenna accommodating chamber 80A.

  In this embodiment, the space | interval D of the antenna 85a and the antenna 85b can be adjusted now by giving allowance to the length of conducting-wire part 86a, 86b. In the sputtering apparatus 1 of the present embodiment, when the antennas 85a and 85b are fixed by the fixing tool 88, the vertical distance D between the antenna 85a and the antenna 85b can be adjusted.

  The fixture 88 is for installing the antennas 85a and 85b in the antenna accommodating chamber 80A. The fixing tool 88 of the present embodiment includes fixing plates 88a and 88b and fixing bolts 88c and 88d. Antennas 85a and 85b are fitted to the fixing plates 88a and 88b. The fixing plates 88a and 88b fitted with the antennas 85a and 85b are attached to the case body 81 with fixing bolts 88c and 88d. A plurality of bolt holes are formed in the case body 81 in the vertical direction, and the fixing plates 88a and 88b are attached to the case body 81 using any one of the bolt holes. That is, the vertical distance D between the antenna 85a and the antenna 85b is adjusted according to the position of the bolt hole used. In order to insulate the antennas 85a and 85b from the fixing plates 88a and 88b, at least the contact surfaces of the antennas 85a and 85b and the fixing plates 88a and 88b are formed of an insulating material.

A procedure for assembling the plasma generating means 80 having the above configuration to the vacuum vessel 11 will be described.
First, the antennas 85 a and 85 b are fixed to the case body 81 using the fixing tool 88. At this time, a fixture 88 that matches the vertical distance D between the antenna 85a and the antenna 85b, the diameter Ra of the antenna 85a, and the diameter Rb of the antenna 85b is used. Subsequently, the dielectric plate 83 is fixed to the case body 81 using the fixing frame 84. As a result, the antennas 85a and 85b are sandwiched between the dielectric plate 83 and the fixed plates 88a and 88b. Further, the case body 81, the dielectric plate 83, the antennas 85a and 85b, and the fixture 88 are integrated. Subsequently, the case body 81 is fixed to the vacuum container 11 with a bolt (not shown) so as to close the opening 11 a of the vacuum container 11. As described above, the plasma generating means 80 is assembled in the vacuum vessel 11, and the antenna accommodating chamber 80A, the reaction process zone 60 (inside the vacuum vessel 11), and the outside of the vacuum vessel 11 are formed as independent spaces, respectively. Antennas 85a and 85b are installed in the antenna accommodating chamber 80A.

  In this embodiment, the case generator 81, the dielectric plate 83, the antennas 85a and 85b, and the fixture 88 are integrated, and the plasma generator 80 is vacuumed by fixing the case assembly 81 and the vacuum vessel 11 with bolts. Since it can be connected to the container 11, the plasma generating means 80 can be easily attached to and detached from the vacuum container 11.

Next, a procedure for generating plasma in the reaction process zone 60 using the sputtering apparatus 1 of the present embodiment will be described.
First, the vacuum pump 15 is operated to decompress the inside of the vacuum container 11 and the antenna accommodating chamber 80A. At this time, the control device opens all the valves V1, V2, and V3 provided in the pipe 15a, and exhausts the inside of the vacuum vessel 11 and the inside of the antenna housing chamber 80A at the same time. The inside of the storage chamber 80A is evacuated. The control device monitors the measurement value of the vacuum gauge so that the pressure difference between the inside of the vacuum container 11 and the inside of the antenna housing chamber 80A does not increase (for example, the pressure difference of 10 ⁴ Pa or more does not occur). The opening and closing of the valves V1, V2, and V3 are appropriately controlled. Thereafter, the control device once closes the valve V2 when the inside of the vacuum vessel 11 reaches 10 ⁻² Pa to 10 Pa. The antenna accommodating chamber 80A is further depressurized to 10 ⁻³ Pa or less. Subsequently, the valve V3 is closed when the inside of the antenna accommodating chamber 80A becomes 10 ⁻³ Pa or less. Subsequently, the reactive gas in the reactive gas cylinder 78 is introduced into the reaction process zone 60 via the mass flow controller 76 in a state where the inside of the vacuum vessel 11 holds 10 ⁻² Pa to 10 Pa.

  A voltage of 13.56 MHz is applied from the high frequency power supply 89 to the antennas 85a and 85b in a state where the inside of the vacuum vessel 11 and the inside of the antenna housing chamber 80A are held at the predetermined pressure, and the reactive gas is applied to the reaction process zone 60. The plasma is generated. At this time, plasma having a distribution according to the vertical distance D between the antenna 85a and the antenna 85b, the diameter Ra of the antenna 85a, the diameter Rb of the antenna 85b, and the like is generated. Plasma processing is performed on the substrate disposed in the substrate holder 13 by the reactive gas plasma generated in the reaction process zone 60.

  As described above, in this embodiment, the antenna that forms a space independent of the inside of the vacuum vessel 11 by holding the inside of the vacuum vessel 11 that forms a space for forming or processing a thin film at a pressure at which plasma is generated. The inside of the storage chamber 80 </ b> A is held at a pressure that is less likely to generate plasma than inside the vacuum container 11, and plasma is generated in the vacuum container 11. For this reason, it is possible to suppress the generation of plasma in the antenna housing chamber 80 </ b> A and to efficiently generate the plasma inside the vacuum container 11.

  Furthermore, in this embodiment, the antenna accommodating chamber 80A and the inside of the vacuum vessel 11 are independent spaces partitioned by the dielectric plate 83, and the antennas 85a and 85b are provided inside the antenna accommodating chamber 80A. Plasma is generated inside the vacuum vessel 11 in a state where the antenna housing chamber 80A is decompressed. For this reason, compared with the conventional case (refer FIG. 7) which generate | occur | produces a plasma in the state which installed antenna 85a, 85b in air | atmosphere, the oxidation of antenna 85a, 85b can be suppressed. Therefore, the lifetime of the antennas 85a and 85b can be increased. In addition, the plasma 85 can be prevented from becoming unstable due to the oxidation of the antennas 85a and 85b.

In the present embodiment, the pressure inside the vacuum vessel 11 and the inside of the antenna housing chamber 80A is monitored, and the pressure is reduced so that a large pressure difference does not occur between the inside of the vacuum vessel 11 and the inside of the antenna housing chamber 80A. The inside of the vacuum vessel 11 is held at a vacuum of about 10 ⁻² Pa to 10 Pa, and the antenna housing chamber 80 ^</ b> A is held at 10 ⁻³ Pa or less to generate plasma inside the vacuum vessel 11. . The antenna housing chamber 80A and the inside of the vacuum vessel 11 are partitioned by a dielectric plate 83, and the antenna housing chamber 80A and the vacuum vessel 11 outside are partitioned by a case body 81. Therefore, compared with the conventional case (see FIG. 7) in which the antenna 185 is installed in the atmosphere and the inside of the vacuum vessel 111 and the outside of the vacuum vessel are partitioned by the dielectric plate 183 (see FIG. 7), this embodiment accommodates the antenna. Since the pressure difference between the chamber 80A and the inside of the vacuum vessel 11 can be kept small, the thickness of the dielectric plate 83 can be designed thinner than the conventional one, and plasma can be generated efficiently. The cost can be reduced by using an inexpensive dielectric plate 83.

  Further, according to the present embodiment, the distribution of plasma with respect to the substrate disposed on the substrate holder 13 can be adjusted by adjusting the vertical distance D between the antenna 85a and the antenna 85b. Further, since the diameter Ra of the antenna 85a, the diameter Rb of the antenna 85b, the thickness of the antennas 85a and 85b, and the like can be changed independently, the diameter Ra of the antenna 85a, the diameter Rb or the thickness of the antenna 85b, etc. The plasma distribution can also be adjusted by adjusting. Further, in the present embodiment, as shown in FIG. 4, the antenna 85a and the antenna 85b have an overall shape composed of large and small semicircles, but the overall shape of the antenna 85a and the antenna 85b is a shape such as a rectangle. It is also possible to adjust the plasma distribution by changing to.

  In particular, the antenna 85a and the antenna 85b can be arranged in the vertical direction intersecting the transport direction of the substrate transported in the horizontal direction, and the distance between the antennas 85a and 85b can be adjusted. When it is necessary to perform plasma treatment over a wide range, the plasma density distribution can be easily adjusted. For example, when plasma processing is performed using the carousel-type sputtering apparatus 1 as in the present embodiment, a thin film positioned above the substrate holder and an intermediate position are determined depending on the arrangement of the substrate on the substrate holder 13, sputtering conditions, and the like. There may be a difference in the film thickness of the thin film located in the area. Even in such a case, if the plasma generating means 80 of the present embodiment is used, there is an advantage that the plasma density distribution can be appropriately adjusted in accordance with the difference in film thickness.

  In the present embodiment, as described above, pyrolytic boron nitride covers the wall surface of the partition wall 16 facing the reaction process zone 60 and the inner wall surface of the vacuum vessel 11 facing the reaction process zone 60. Thus, the density of radicals in the reaction process zone 60 is maintained high, and more radicals are brought into contact with the thin film on the substrate to increase the efficiency of the plasma processing. That is, by covering the partition wall 16 and the inner wall surface of the vacuum vessel 11 with chemically stable pyrolytic boron nitride, radicals generated in the reaction process zone 60 by the plasma generating means 80 or excited radicals are separated from the partition wall 16. It is suppressed that it reacts with the inner wall surface of the vacuum vessel 11 and disappears. Further, the radical generated in the reaction process zone 60 by the partition wall 16 can be controlled so as to be directed toward the substrate holder.

Hereinafter, as a plasma processing method using the above-described sputtering apparatus 1, plasma processing is performed on a thin film of incomplete silicon oxide (SiOx ₁ (x ₁ <2)) formed on a substrate by sputtering. An example of a method for forming a thin film of silicon oxide (SiOx ₂ (x ₁ <x ₂ ≦ 2)) that is more oxidized than complete silicon oxide will be described. Incomplete silicon oxide is incomplete silicon oxide SiOx (x <2) deficient in oxygen, which is a constituent element of silicon oxide SiO ₂ .

  First, the substrate and the targets 29 a and 29 b are arranged in the sputtering apparatus 1. The substrate is held by the substrate holder 13. Targets 29a and 29b are held by magnetron sputter electrodes 21a and 21b, respectively. Silicon (Si) is used as the material of the targets 29a and 29b. Next, the inside of the vacuum container 11 and the inside of the antenna housing chamber 80A are depressurized to the predetermined pressure described above, the motor 17 is operated, and the substrate holder 13 is rotated. Thereafter, after the pressure inside the vacuum vessel 11 and the inside of the antenna housing chamber 80A is stabilized, the pressure in the film forming process zone 20 is adjusted to 0.1 Pa to 1.3 Pa.

  Next, argon gas, which is an inert gas for sputtering, and oxygen gas, which is a reactive gas, are adjusted in the film forming process zone 20 from the sputtering gas cylinder 27 and the reactive gas cylinder 28 by the mass flow controllers 25 and 26. Then, the atmosphere for performing sputtering in the film forming process zone 20 is adjusted. Next, an AC voltage having a frequency of 1 to 100 KHz is applied from the medium frequency AC power source 23 to the magnetron sputter electrodes 21a and 21b via the transformer 24 so that an alternating electric field is applied to the targets 29a and 29b. Thereby, at a certain point in time, the target 29a becomes the cathode (negative pole), and at that time, the target 29b always becomes the anode (positive pole). When the direction of the alternating current changes at the next time point, the target 29b becomes the cathode (minus pole) and the target 29a becomes the anode (plus pole). In this way, the pair of targets 29a and 29b alternately become an anode and a cathode, so that plasma is formed and sputtering is performed on the target on the cathode.

During sputtering, non-conductive or low-conductive silicon oxide (SiOx (x ≦ 2)) may be deposited on the anode, but this anode is converted into a cathode by an alternating electric field. Then, these silicon oxides (SiOx (x ≦ 2)) are sputtered, and the target surface is in an original clean state. Then, by repeating the pair of targets 29a and 29b alternately becoming an anode and a cathode, a stable anode potential state is always obtained, and a change in plasma potential (almost equal to the normal anode potential) is prevented, and the substrate A thin film made of silicon or incomplete silicon oxide (SiOx ₁ (x ₁ <2)) is stably formed on the film forming surface. The composition of the thin film formed in the film formation process zone 20 is changed to silicon (Si) by adjusting the flow rate of the oxygen gas introduced into the film formation process zone 20 and controlling the rotation speed of the substrate holder 13. Or silicon oxide (SiO ₂ ), or incomplete silicon oxide (SiOx ₁ (x ₁ <2)).

After forming a thin film of silicon or incomplete silicon oxide (SiOx ₁ (x ₁ <2)) on the film forming surface of the substrate in the film forming process zone 20, the substrate is formed by rotating the substrate holder 13. The film is transported from a position facing the membrane process zone 20 to a position facing the reaction process zone 60. In the reaction process zone 60, oxygen gas is introduced as a reactive gas from a reactive gas cylinder 78, and argon gas is introduced as an inert gas from an inert gas cylinder 77. Next, a high frequency voltage of 13.56 MHz is applied to the antennas 85a and 85b, and plasma is generated in the reaction process zone 60 by the plasma generating means 80. The pressure in the reaction process zone 60 is maintained at 0.7 Pa to 1 Pa. Further, at least during the generation of plasma in the reaction process zone 60, the pressure inside the antenna accommodating chamber 80A is maintained at 10 ⁻³ Pa or less.

Next, when the substrate holder 13 rotates and the substrate on which a thin film made of silicon or incomplete silicon oxide (SiOx ₁ (x ₁ <2)) is formed is transported to a position facing the reaction process zone 60. In the reaction process zone 60, a thin film made of silicon or incomplete silicon oxide (SiOx ₁ (x ₁ <2)) is subjected to an oxidation reaction by plasma treatment. That is, silicon or incomplete silicon oxide (SiOx ₁ (x ₁ <2)) is oxidized by the plasma of oxygen gas generated in the reaction process zone 60 by the plasma generating means 80, and the incomplete silicon oxide having a desired composition is obtained. (SiOx ₂ (x ₁ <x ₂ <2)) or silicon oxide (SiO ₂ ).

  Through the above steps, in the above example, a silicon oxide (SiOx (x ≦ 2)) thin film having a desired composition can be formed. Furthermore, by repeating the above steps, a thin film having a desired film thickness can be formed by laminating thin films.

  The above has described the case of forming a silicon oxide (SiOx (x ≦ 2)) thin film having a desired composition, but by performing sputtering by providing a plurality of film formation process zones for performing sputtering, A thin film in which thin films having different compositions are repeatedly laminated can also be formed. For example, as described above, the film formation process zone 40 is provided in the sputtering apparatus 1 and niobium (Nb) is used as the targets 49a and 49b. Then, a niobium oxide (NbOy (y <2.5)) thin film having a desired composition is formed on the silicon oxide thin film by the same method as that for forming the silicon oxide thin film. Then, by repeating the steps of sputtering in the film forming process zone 20, oxidation by plasma processing in the reaction process zone 60, sputtering in the film forming process zone 40, and oxidation by plasma processing in the reaction process zone 60, a desired process is repeated. A thin film in which a silicon oxide (SiOx (x ≦ 2)) thin film and a niobium oxide (NbOy (y ≦ 2.5)) thin film having a composition are repeatedly stacked can be formed.

The embodiment described above can be modified, for example, as in the following (a) to (l). Further, (a) to (l) can be modified in appropriate combination. In the following description, the same members as those in the above embodiment are described using the same reference numerals.
(A) In the above embodiment, the sputtering apparatus has been described as an example of the thin film forming apparatus. However, the plasma generating means can be applied to other types of thin film forming apparatuses. As the thin film forming apparatus, for example, an etching apparatus that performs etching using plasma, a CVD apparatus that performs CVD using plasma, or the like may be used. Further, the present invention can be applied to a surface treatment apparatus that performs plasma surface treatment using plasma.
(B) In the above embodiment, a so-called carousel type sputtering apparatus is used, but the present invention is not limited to this. The present invention can also be applied using other sputtering apparatuses in which the substrate is transported facing a region where plasma is generated.

  (C) In the above embodiment, the dielectric plate 83 is fixed to the case body 81 using the fixing frame 84, and the case body 81, the dielectric plate 83, the antennas 85a and 85b, and the fixture 88 are integrated. In this state, the case body 81 and the vacuum vessel 11 were fixed with bolts to connect the plasma generating means to the vacuum vessel 11. However, the method of fixing the dielectric plate 83 and the method of connecting the plasma generating means are not limited to this. For example, as shown in FIG. FIG. 5 is a main part explanatory view for explaining another embodiment of the plasma generating means. In the embodiment shown in FIG. 5, the dielectric plate 183 as a dielectric wall is connected between the vacuum vessel 111 and the fixed frame 184 by connecting the vacuum vessel 111 and the fixed frame 184 with bolts (not shown). The dielectric plate 183 is fixed to the vacuum vessel 111 by being sandwiched. A case body 181 as a lid is fixed to the vacuum container 111 with a bolt so as to cover the dielectric plate 183 fixed to the vacuum container 111, and the plasma generating means 180 is fixed to the vacuum container 111.

  An antenna accommodating chamber 180A is formed surrounded by the case body 181 and the dielectric plate 183. A pipe 15a is connected to the antenna accommodating chamber 180A, and a vacuum pump 15 is connected to the end of the pipe 15a so that the inside of the antenna accommodating chamber 180A can be decompressed. In the above embodiment, the antennas 85a and 85b are fixed to the case body 181 using the fixing tool 188 in the same manner as the antennas 85a and 85b are fixed to the case body 81 using the fixing tool 88. Yes. If the case body 181 is detached from the vacuum vessel 111, the antennas 85a and 85b can be easily attached and detached, and the shapes of the antennas 85a and 85b can be easily changed.

  (D) In the above embodiment, as the plasma generating means, inductive coupling in which the antennas 85a and 85b that form a vortex in the same plane with respect to the plate-like dielectric plate 83 are fixed as shown in FIGS. Although a type (flat plate type) plasma generating means is used, the present invention is also applicable to a thin film forming apparatus provided with other types of plasma generating means. That is, high frequency power is applied to an antenna wound in a spiral around a cylindrical dielectric wall made of a dielectric material, and an induction electric field is generated in a region surrounded by the cylindrical dielectric wall. The present invention can also be applied to inductively coupled (cylindrical) plasma generating means for generating plasma.

  FIG. 6 is a main part explanatory view for explaining inductively coupled (cylindrical) plasma generating means. In the embodiment shown in FIG. 6, a dielectric plate 283 is provided as a dielectric wall. The dielectric plate 283 has a cylindrical shape. By connecting the vacuum vessel 211 and the fixed frame 284 with bolts (not shown), the dielectric plate 283 as the dielectric wall of the present invention is sandwiched between the vacuum vessel 211 and the fixed frame 284, and the dielectric The plate 283 is fixed to the vacuum vessel 211. A case body 281 as a lid is fixed to the vacuum container 211 with a bolt so as to cover the dielectric plate 283 fixed to the vacuum container 211, and the plasma generating means 280 is fixed to the vacuum container 211.

  An antenna housing chamber 280A is formed surrounded by the case body 281 and the dielectric plate 283. A pipe 15a is connected to the antenna receiving chamber 280A, and a vacuum pump 15 is connected to the tip of the pipe 15a so that the inside of the antenna receiving chamber 280A can be decompressed. The antenna 285 is wound around the outer periphery of a cylindrical dielectric plate. The antenna 285 is fixed to the case body 281 using the fixing tool 288 in the same manner as the antennas 85 a and 85 b are fixed to the case body 81 using the fixing tool 88 in the above embodiment. When the case body 281 is detached from the vacuum vessel 211, the attachment and detachment of the antenna 285, the change of the shape of the antenna 285, and the like can be easily performed.

  In the embodiment shown in FIG. 6, the dielectric plate 283 is sandwiched between the case body 281 and the fixed frame 84, thereby fixing the dielectric plate 283 to the case body 281. The plate 283, the antenna 285, and the fixture 288 can be integrated. With this configuration, the plasma generating means 280 can be connected to the vacuum container 211 by fixing the case body 281 and the vacuum container 211 with bolts, so that the plasma generating means 280 can be easily attached to and detached from the vacuum container 211. .

(E) In the above embodiment, the piping 15a is connected to both the inside of the vacuum vessel 11 and the inside of the antenna accommodating chamber 80A, and the vacuum pump 15 connected to the piping 15a is used to connect the inside of the vacuum vessel 11 and the antenna. The storage chamber 80A was exhausted. However, independent piping is connected to the inside of the vacuum vessel 11 and the inside of the antenna accommodating chamber 80A, and the inside of the vacuum vessel 11 and the inside of the antenna accommodating chamber 80A are exhausted by an independent vacuum pump connected to each piping. You may do it.
(F) In the above embodiment, the dielectric plates 83 are fitted to the fixing plates 88a and 88b, and the fixing plates 88a and 88b are fixed to the case body 81 with the fixing bolts 88c and 88d. Although it is installed in the antenna accommodating chamber 80A, in short, other methods may be used as long as the distances D can be adjusted to fix the antennas 85a and 85b.

  (G) In the above embodiment, the protective layer P made of pyrolytic boron nitride is formed on the surface of the partition wall 16 facing the reaction process zone 60 and the reaction process zone 60 of the inner wall surface of the vacuum vessel 11. The protective layer P made of pyrolytic boron nitride may be formed in other portions. For example, not only the wall surface of the partition wall 16 facing the reaction process zone 60 but also other portions of the partition wall 16 may be coated with pyrolytic boron nitride. Thereby, it is possible to prevent the radicals from reacting with the partition wall 16 and reducing the radicals as much as possible. Further, for example, not only a portion of the inner wall surface of the vacuum vessel 11 facing the reaction process zone 60 but also other portions of the inner wall surface of the vacuum vessel 11, for example, the entire inner wall surface may be coated with pyrolytic boron nitride. . Thereby, it is possible to avoid the radicals from reacting with the inner wall surface of the vacuum vessel 11 and reducing the radicals to the maximum extent. The partition wall 12 may be coated with pyrolytic boron nitride.

(H) In the above embodiment, the case where pyrolytic boron nitride is coated on the wall surface facing the reaction process zone 60 of the partition wall 16 or the inner wall surface of the vacuum vessel 11 has been described. However, aluminum oxide (Al ₂ O ₃ ), Silicon oxide (SiO ₂ ), and boron nitride (BN), the radicals in the plasma generated by the plasma generating means or the radicals in the excited state can be It can suppress disappearing by reacting with the wall surface.
(I) In the above embodiment, the tubular main body of the antenna 85a is made of copper and the coating layer is made of silver. However, the main body is made of a material that is inexpensive and easy to process and has low electrical resistance, Since the coating layer on which the current concentrates may be formed of a material having a lower electrical resistance than that of the main body, a combination of other materials may be used. For example, the main body portion may be formed of aluminum or an aluminum-copper alloy, or the coating layer may be formed of copper or gold. The main body portion and the covering layer of the antenna 85b can be similarly modified. Further, the antenna 85a and the antenna 85b may be formed of different materials.

(J) In the above embodiment, oxygen is introduced into the reaction process zone 60 as a reactive gas, but in addition, an oxidizing gas such as ozone or dinitrogen monoxide (N ₂ O), or a nitriding nitrogen or the like The present invention can be applied to plasma treatment other than oxidation treatment by introducing a reactive gas, a carbonaceous gas such as methane, and a fluorinated gas such as fluorine and carbon tetrafluoride (CF ₄ ).
(K) In the above embodiment, silicon is used as the material for the targets 29a and 29b, and niobium is used as the material for the targets 49a and 49b. However, the present invention is not limited to this, and these oxides may be used. it can. Also, aluminum (Al), titanium (Ti), zirconium (Zr), tin (Sn), chromium (Cr), tantalum (Ta), tellurium (Te), iron (Fe), magnesium (Mg), hafnium (Hf ), Nickel-chromium (Ni-Cr), indium-tin (In-Sn), or other metals can be used. Moreover, compounds of these metals, for example, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , HfO _2, etc. can also be used. Of course, the materials of the targets 29a, 29b, 49a, 49b may all be the same. When these targets are used, optical films such as Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , SiO ₂ , Nb ₂ O ₅ , HfO ₂ , and MgF ₂ are obtained by plasma treatment in the reaction process zone 60. Alternatively, an insulating film, a conductive film such as ITO, a magnetic film such as Fe ₂ O ₃ , and a super hard film such as TiN, CrN, and TiC can be formed. Insulating metal compounds such as TiO ₂ , ZrO ₂ , SiO ₂ , Nb ₂ O ₅ , and Ta ₂ O ₅ have extremely slow sputtering rates and poor productivity compared to metals (Ti, Zr, Si). In particular, it is effective to perform plasma treatment using the thin film forming method of the present invention.

  (L) In the above embodiment, the target 29a and the target 29b, and the target 49a and the target 49b are made of the same material, but may be made of different materials. When the same metal target is used, as described above, an incomplete reaction product of a single metal is formed on the substrate by sputtering, and when a different metal target is used, an incomplete reaction product of the alloy is formed. Formed on the substrate.

  DESCRIPTION OF SYMBOLS 1 ... Sputtering device, 11, 111, 211 ... Vacuum container, 11a ... Opening, 12, 14, 16 ... Partition wall, 13 ... Substrate holder, 15 ... Vacuum pump, 15a ... Piping, 17 ... Motor, 20, 40 ... Film formation process zone, 21a, 21b, 41a, 41b ... Magnetron sputtering electrode, 23, 43 ... Medium frequency AC power supply, 24, 44 ... Transformers, 25, 26, 45, 46, 75, 76 ... Mass flow controllers, 27, 47 ... Sputter gas cylinders, 28, 48, 78 ... Reactive gas cylinders, 29a, 29b, 49a, 49b ... Target, 60 ... Reaction process zone, 77 ... Inert gas cylinder, 80, 180, 280 ... Plasma generating means, 80A, 180A, 280A ... Tena accommodating chamber, 81, 181, 281 ... case body, 81a ... insertion hole, 81b ... seal member, 83, 183, 283 ... dielectric plate, 84, 184, 284 ... fixed Frame, 85a, 85b, 285 ... Antenna, 86a, 86b ... Conductor part, 87 ... Matching box, 87a, 87b ... Variable capacitor, 88, 188, 288 ... Fixing tool, 88a, 88b ... fixed plate, 88c, 88d ... fixed bolt, 89 ... high frequency power supply, 311 ... vacuum vessel, 380 ... plasma generating means, 383 ... dielectric plate, 385 ... Antenna, 387a, 387b ... Variable capacitor, 387c ... Coil for matching, V1, V2, V3 ... Valve

Claims (3)

A vacuum vessel that maintains a vacuum inside, and plasma generation means that is connected to the vacuum vessel and generates plasma in the vacuum vessel, the plasma generation means comprising a dielectric wall formed of a dielectric, An antenna installed adjacent to the dielectric wall; a lid that forms an antenna housing chamber for housing the antenna together with the dielectric wall; and a decompression means for evacuating the antenna housing chamber to a vacuum state. And the interior of the vacuum container and the interior of the antenna housing chamber are partitioned by the dielectric wall to form an independent space, and the antenna housing chamber is lower than the vacuum container by 10 A thin film forming method for forming a thin film using a thin film forming apparatus maintained in a vacuum state of ⁻³ Pa or less,
A depressurizing step of reducing the inside of the antenna housing chamber to a vacuum state of 10 ⁻³ Pa or less lower than the vacuum container, while making the inside of the vacuum container a vacuum state;
A method of forming a thin film by applying a high frequency voltage to the antenna to generate plasma inside the vacuum container and plasma-treating the thin film formed in the vacuum container. . The thin film forming method according to claim 1, wherein, in the decompression step, a pressure difference between the antenna housing chamber and the vacuum container is reduced. In the depressurization step, the inside of the vacuum container and the inside of the antenna housing chamber are simultaneously evacuated, the inside of the vacuum container is depressurized to 10 ⁻² Pa to 10 Pa, and then the antenna housing chamber is 10 ⁻³ from the vacuum container. The thin film forming method according to claim 1, wherein the pressure is reduced to Pa or less.

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