CN113924384B

CN113924384B - Film forming apparatus

Info

Publication number: CN113924384B
Application number: CN202080040665.9A
Authority: CN
Inventors: 小野大祐
Original assignee: Shibaura Mechatronics Corp
Current assignee: Shibaura Mechatronics Corp
Priority date: 2019-06-06
Filing date: 2020-06-02
Publication date: 2024-02-09
Anticipated expiration: 2040-06-02
Also published as: WO2020246449A1; JPWO2020246449A1; TW202113105A; TWI758740B; CN113924384A; JP7469303B2

Abstract

The invention provides a film forming apparatus capable of forming a flat film for suppressing deterioration of optical characteristics. The film forming apparatus is a film forming apparatus for forming a film on a workpiece (10), and includes: a conveying unit (30) having a rotary table (31) for circularly conveying the workpiece (10); a film formation processing unit (40) that has a target (42) containing a material constituting a film, and a plasma generator that plasmatizes a sputtering gas introduced between the target (42) and the turntable (31), and that forms the film on the workpiece (10) by sputtering the target (42) with the plasma; and an ion irradiation unit (60) for irradiating ions; the conveying unit (30) conveys the workpiece (10) in a circulating manner so that the workpiece (10) passes through the film formation processing unit (40) and the ion irradiation unit (60), and the ion irradiation unit (60) irradiates ions on the film formed on the workpiece (10).

Description

Film forming apparatus

Technical Field

The present invention relates to a film forming apparatus.

Background

An optical film is formed on the optical device, and reflects light in a predetermined wavelength region and transmits light in other wavelength regions. Examples of the optical device include: cold light mirrors such as liquid crystal projector, photocopier, and condenser of infrared sensor. The cold light mirror is formed with a laminated film that is an optical film that reflects visible light and transmits light in a predetermined wavelength range. As a method for forming such a laminated film, a method is known in which a target containing a film-forming material is exposed to plasma by sputtering, whereby particles constituting the target are ejected, and the particles are deposited on a workpiece.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2005-266538

Disclosure of Invention

Problems to be solved by the invention

Here, it is known that a stacked film formed by sputtering generates a portion where deposited particles are sparse and a portion where deposited particles are dense, thereby generating irregularities on the surface of the film. When the laminated film, which is an optical film in which the films having irregularities on the surfaces thereof are laminated as described above, diffuse reflection of light occurs at the interface between the films, and optical characteristics such as transmittance deteriorate.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a film forming apparatus capable of forming a flat film which suppresses deterioration of optical characteristics.

Technical means for solving the problems

The film forming apparatus of the present invention is a film forming apparatus for forming a film on a workpiece, comprising: a chamber for evacuating the interior; a conveying part which is arranged in the chamber and is provided with a rotary table for circularly conveying the workpiece on a circumferential conveying path; a film forming processing section having a target containing a material constituting the film and a plasma generator for plasmatizing a sputtering gas introduced between the target and the turntable, the target being sputtered by plasma to form a film on the workpiece; a film processing unit having a tubular body protruding into an inner space of the chamber and opening into the transport path, a window member provided so as to block an opening of the tubular body, a first process gas introduction unit for introducing a first process gas into a processing space formed between the turntable and the tubular body, an antenna for generating an electric field in the processing space through the window member, and a power supply for applying a high-frequency voltage to the antenna, and generating inductively coupled plasma in the processing space by plasmatizing the first process gas to cause a chemical reaction of the film; and an ion irradiation section having a cylindrical electrode provided with an opening at one end and attached to the chamber so that the opening faces the conveyance path, a second process gas introduction section for introducing a second process gas into the cylindrical electrode, and a power supply for applying a high-frequency voltage to the cylindrical electrode, the ion irradiation section irradiating the film with ions generated by plasmatizing the second process gas; the transport unit transports the workpiece in a circulating manner so that the workpiece passes through the film formation processing unit, the film processing unit, and the ion irradiation unit irradiates ions on the film on the workpiece during formation.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a film forming apparatus capable of forming a flat film with suppressed deterioration of optical characteristics can be obtained.

Drawings

Fig. 1 is a perspective plan view schematically showing the structure of a film forming apparatus according to an embodiment.

Fig. 2 is a section A-A of fig. 1.

Fig. 3 is a sectional view of B-B of fig. 1.

Fig. 4 is a flowchart of a process performed by the film forming apparatus according to the embodiment.

Fig. 5 is a schematic view showing a process of a workpiece using the film forming apparatus according to the embodiment.

Fig. 6 (a) to 6 (c) are cross-sectional images of example 1, example 2 and comparative example 1 taken by a transmission electron microscope (Transmission Electron Microscope, TEM), fig. 6 (a) is a cross-sectional image of example 1, fig. 6 (b) is a cross-sectional image of example 2, and fig. 6 (c) is a cross-sectional image of comparative example 1.

Fig. 7 (a) to 7 (c) are enlarged cross-sectional images of the eight-layer portions of the surface layers of example 1, example 2 and comparative example 1 in fig. 6 (a) to 6 (c), fig. 7 (a) is a cross-sectional image of example 1, fig. 7 (b) is a cross-sectional image of example 2, and fig. 7 (c) is a cross-sectional image of comparative example 1.

Fig. 8 is a graph showing the maximum height Rz of each layer in example 1, example 2, and comparative example 1.

Fig. 9 is a graph showing standard deviations of maximum heights Rz of the respective layers of example 1, example 2, and comparative example 1.

Description of symbols

10: workpiece

11：SiO ₂ Film and method for producing the same

12：Nb ₂ O ₅ Film and method for producing the same

20: chamber chamber

20a: top part

20b: inner bottom surface

20c: an inner peripheral surface

21: exhaust port

21a: an opening

22: partition part

30: conveying part

31: rotary table

32: motor with a motor housing

33: holding part

34: tray for holding food

40. 40a, 40b: film forming processing unit

41: processing space

42: target(s)

43: support plate

44: electrode

46: power supply unit

47: gas inlet

48: piping arrangement

49: sputtering gas introduction part

50: film processing unit

51: cylindrical body

52: window component

53: antenna

54: RF power supply

55: matching box

56: gas inlet

57: piping arrangement

58: process gas introduction section

59: processing space

60: ion irradiation part

61: cylindrical electrode

61a: an opening part

61b: flange

62: insulating member

63: shell body

64: protective cover

65: process gas introduction section

66: RF power supply

67: matching box

70: load/unload unit

80: control device

90: exhaust part

100: film forming apparatus

G1: sputtering gas

And G2: process gas

And G3: process gas

Detailed Description

(embodiment)

(Structure)

Embodiments of a film forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 is a perspective plan view schematically showing the structure of a film forming apparatus 100 according to the present embodiment. The film forming apparatus 100 is an apparatus for forming a film on a workpiece 10. The work 10 is a glass substrate or a resin substrate. The film formed on the work 10 by the film forming apparatus 100 is a laminated film in which a plurality of films are laminated. In the present embodiment, the film is a laminated film to be an optical film, for example, siO ₂ Film and Nb ₂ O ₅ The films are alternately laminated.

The film forming apparatus 100 includes: a chamber 20, a carrying section 30, a film formation processing section 40, a film processing section 50, an ion irradiation section 60, a load-and-unload (load-lock) section 70, and a control device 80.

(Chamber)

The chamber 20 is a cylindrical container in which the inside can be vacuumed. The chamber 20 is divided by a partition 22 and divided into a plurality of areas in a fan shape. In each region, any one of the film formation processing section 40, the film processing section 50, the ion irradiation section 60, and the loading/unloading section 70 is arranged. The respective units 40, 50, 60, 70 are arranged in the order of the film formation processing unit 40, the film processing unit 50, the ion irradiation unit 60, and the loading/unloading unit 70 with respect to the conveyance direction (counterclockwise direction in fig. 1) of the conveyance unit 30. The film processing section 50 and the ion irradiation section 60 are disposed adjacently.

As shown in fig. 2, the chamber 20 is formed by surrounding a disk-shaped top 20a, a disk-shaped inner bottom 20b, and an annular inner peripheral surface 20 c. The partition 22 is a square wall plate radially disposed from the center of the cylindrical shape, and extends from the top 20a toward the inner bottom 20b so as not to reach the inner bottom 20b. That is, a columnar space is secured on the inner bottom surface 20b side. A turntable 31 for conveying the workpiece 10 is disposed in the columnar space. The lower end of the partition 22 is spaced apart from a gap through which the workpiece 10 placed on the conveying unit 30 passes, and faces the placement surface of the workpiece 10 on the turntable 31. The processing space for processing the workpiece 10 is partitioned by the partition 22 among the film formation processing section 40, the film processing section 50, and the ion irradiation section 60. This suppresses diffusion of the sputtering gas G1 of the film formation processing section 40, the process gas (first process gas) G2 of the film formation processing section 50, and the process gas (second process gas) G3 (see fig. 3) of the ion irradiation section 60 into the chamber 20.

As will be described later, although plasma is generated in the processing space in the film formation processing section 40, the film processing section 50, and the ion irradiation section 60, the pressure in the processing space divided into smaller spaces than the chamber 20 is only required to be adjusted, so that the pressure adjustment can be easily performed, and the discharge of plasma can be stabilized. Further, an exhaust port 21 is provided in the chamber 20. An exhaust portion 90 is connected to the exhaust port 21. The exhaust section 90 includes piping, pumps, valves, and the like, which are not shown. The inside of the chamber 20 can be depressurized to be vacuum by the exhaust of the exhaust portion 90 through the exhaust port 21.

(conveying part)

The conveying unit 30 includes a turntable 31, a motor 32, and a holding unit 33, and conveys the workpiece 10 in a circulating manner along a conveying path L that is a circumferential path. That is, the conveying section 30 conveys the workpiece 10 in a circulating manner so that the workpiece 10 passes through the film formation processing section 40, the film formation processing section 50, and the ion irradiation section 60 in this order. Therefore, the conveying section 30 conveys the workpiece 10 so that the workpiece 10 alternately passes through the film formation processing section 40 and the ion irradiation section 60.

The turntable 31 has a disk shape and is greatly expanded to the extent that it does not contact the inner peripheral surface 20 c. The motor 32 continuously rotates at a predetermined rotation speed with the center of the circle of the turntable 31 as a rotation axis. In the present embodiment, the motor 32 rotates the rotary table 31 counterclockwise as shown in fig. 1. The holding portion 33 is a groove, a hole, a projection, a jig, a fixture, or the like disposed at a circumferentially equidistant position on the upper surface of the turntable 31, and holds the tray 34 on which the workpiece 10 is placed by a mechanical chuck or an adhesive chuck. The workpieces 10 are arranged in a matrix on the pallet 34, for example, and six holding portions 33 are arranged at 60 ° intervals on the turntable 31.

(film Forming processing section)

The film formation processing section 40 generates plasma, and exposes a target 42 containing a film formation material to the plasma. Thus, the film formation processing unit 40 deposits particles constituting the target 42, which are ejected by causing ions contained in the plasma to collide with the target 42, on the workpiece 10, thereby forming a film. As shown in fig. 2, the film formation processing section 40 includes: a sputtering source including a target 42, a backing plate 43, and an electrode 44, and a plasma generator including a power supply portion 46 and a sputtering gas introduction portion 49.

The target 42 is a plate-like member including a film-forming material deposited on the workpiece 10 to form a film. The target 42 serves as a supply source of particles constituting a film formed on the workpiece 10. The target 42 is provided separately on the conveying path L of the workpiece 10 placed on the turntable 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 turntable 31. For example three targets 42 are provided. Three targets 42 are arranged at positions arranged on the vertices of a triangle in plan view.

The backing plate 43 is a support member holding the target 42. The backing plate 43 individually holds each target 42. The electrode 44 is a conductive member for applying electric power from the outside of the chamber 20 to each target 42 individually, and is electrically connected to the target 42. The power applied to each target 42 may be individually varied. The sputtering source preferably includes a magnet, a cooling mechanism, and the like, as necessary.

The power supply 46 is, for example, a Direct Current (DC) power supply to which a high voltage is applied, and is electrically connected to the electrode 44. The power supply 46 applies electric power to the target 42 via the electrode 44. The turntable 31 has the same potential as the grounded chamber 20, and a high voltage is applied to the target 42 side to generate a potential difference. The power supply 46 may be a Radio Frequency (RF) power supply for high-Frequency sputtering.

As shown in fig. 2, the sputtering gas introduction portion 49 introduces the sputtering gas G1 into the chamber 20. The sputtering gas introduction portion 49 includes a supply source of sputtering gas G1 such as a gas cylinder, not shown, a pipe 48, and a gas introduction port 47.

The pipe 48 is connected to a supply source of the sputtering gas G1, penetrates the chamber 20 in an airtight manner, and extends into the chamber 20, and its end is opened as a gas inlet 47.

The gas inlet 47 opens between the turntable 31 and the target 42, and introduces the sputtering gas G1 for film formation into the processing space 41 formed between the turntable 31 and the target 42. As the sputtering gas G1, an inert gas, preferably argon gas, or the like can be used.

In the film formation processing section 40, when the sputtering gas G1 is introduced from the sputtering gas introduction section 49 and a high voltage is applied to the target 42 via the electrode 44 by the power supply section 46, the sputtering gas G1 introduced into the processing space 41 formed between the turntable 31 and the target 42 is plasmatized, and active species such as ions are generated. Ions in the plasma collide with the target 42, and particles constituting the target 42 (hereinafter, also referred to as target constituting particles) are ejected. The work 10 circularly conveyed by the turntable 31 passes through the processing space 41. The target constituent particles that have been knocked out are deposited on the workpiece 10 as the workpiece 10 passes through the processing space 41, and a film containing the target constituent particles is formed on the workpiece 10. The workpiece 10 is circularly conveyed by the turntable 31 and repeatedly passes through the processing space 41, thereby performing film formation processing. The thickness of the film deposited each time the film passes through the film formation processing section 40 depends on the processing rate of the film formation processing section 50, but may be, for example, a thin film of about 1 atomic scale to 2 atomic scale (5 nm or less). The work 10 is circularly carried a plurality of times, whereby the thickness of the film increases, and a film having a predetermined film thickness is formed on the work 10.

The pressure of the sputtering gas in the film formation processing section 40 may be set to 0.3Pa or less, and may be lower than 0.3Pa as long as the pressure can maintain the plasma generated in the processing space 41 of the film formation processing section 40.

In the present embodiment, the film forming apparatus 100 includes a plurality of (here, two) film forming process units 40, and the film forming process units 40 are provided in two areas separated by the separating unit 22. The plurality of film formation processing units 40 selectively deposit film formation materials, thereby forming films including layers of the plurality of film formation materials. In particular, in the present embodiment, a film including a layer of a plurality of film forming materials is formed by including sputtering sources corresponding to different types of film forming materials and selectively depositing the film forming materials. The term "including a sputtering source corresponding to a different type of film forming material" includes both a case where the film forming materials of all the film forming process portions 40 are different and a case where the film forming materials are common to a plurality of film forming process portions 40, but other film forming materials are different from each other. The selective deposition of one of the film forming materials means that the film forming process portion 40 of the other film forming material does not perform film formation while the film forming process portion 40 of any one of the film forming materials performs film formation.

In the present embodiment, the target 42 of one of the film formation processing portions 40 contains silicon (Si), and the target 42 of the other film formation processing portion 40 contains niobium (Nb). The niobium film is not formed during the formation of the silicon film, and the silicon film is not formed during the formation of the niobium film. In order to distinguish between the two film formation processing units 40, the film formation processing unit 40 having the target 42 containing silicon (Si) is referred to as a film formation processing unit 40a, and the film formation processing unit 40 having the target 42 containing niobium (Nb) is referred to as a film formation processing unit 40b.

(film treatment section)

The film processing section 50 generates an inductively coupled plasma in the processing space 59 into which the process gas is introduced, and chemically reacts ions in the plasma with the film formed on the workpiece 10 by the film formation processing section 40, thereby generating a compound film. The process gas being introduced, e.g. containing oxygen or nitrogenAnd (3) air. The process gas may contain an inert gas such as argon in addition to oxygen or nitrogen. When the process gas contains oxygen, the film processing section 50 oxidizes the film on the workpiece 10. When the process gas contains nitrogen, the film processing section 50 nitrides the film on the workpiece 10. The process gas of the present embodiment is oxygen. The film processing section 50 plasmatizes oxygen gas, and chemically reacts ions in the plasma with a silicon film or a niobium film located on the outermost surface of the workpiece 10 to generate SiO ₂ Film, nb ₂ O ₅ And (3) a film.

The film processing section 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 section 58.

As shown in fig. 1 and 2, the tubular body 51 is a tubular body having a rectangular shape with rounded corners in horizontal cross section, and has an opening. The cylindrical body 51 is fitted into the top 20a of the chamber 20 so that its opening is directed toward the turntable 31 side separately, and protrudes toward the inner space of the chamber 20. The cylindrical body 51 is made of the same material as the turntable 31. The window member 52 is a flat plate of dielectric such as quartz having a shape substantially similar to the horizontal cross section of the cylindrical body 51. The window member 52 is provided so as to close the opening of the cylindrical body 51, and separates the processing space 59 in the chamber 20 into which the process gas G2 containing oxygen is introduced from the inside of the cylindrical body 51. The processing space 59 is a space formed between the turntable 31 and the inside of the tubular body 51 in the film processing section 50. The workpiece 10 circularly conveyed by the turntable 31 repeatedly passes through the processing space 59, thereby performing oxidation processing. The window member 52 may be a dielectric such as alumina or a semiconductor such as silicon.

The antenna 53 is a coil-shaped conductor, and is disposed in the inner space of the tubular 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. The antenna 53 is desirably disposed near the window member 52 so that an electric field generated from the antenna 53 is efficiently introduced into the processing space 59 through the window member 52. An RF power supply 54 for applying a high-frequency voltage is connected to the antenna 53. A matching box 55 as a matching circuit is connected in series to the output side of the RF power supply 54. The matching box 55 stabilizes the discharge of the plasma by matching the impedance of the input side and the output side.

As shown in fig. 2, the process gas introduction portion 58 introduces the process gas G2 containing oxygen into the process space 59. The process gas introduction portion 58 includes a supply source of 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 a supply source of the process gas G2, penetrates the chamber 20 in an airtight manner, and extends into the chamber 20, and its end is opened as a gas introduction port 56.

The gas inlet 56 opens into the process space 59 between the window member 52 and the turntable 31, and introduces the process gas G2.

In this film processing section 50, a high-frequency voltage is applied from an RF power source 54 to an antenna 53. Thereby, a high-frequency current flows into the antenna 53, and an electric field is generated by electromagnetic induction. The electric field is introduced into the processing space 59 through the window member 52 to generate an inductively coupled plasma of the process gas G2. At this time, the oxygen is also ionized, and oxygen ions collide with the film on the workpiece 10 and bond with atoms constituting the film. As a result, the film on the work 10 is oxidized, and an oxide film is formed as a compound film.

(ion irradiation section)

The ion irradiation unit 60 irradiates ions on the object. The ion irradiation unit 60 plasmatizes the process gas and irradiates ions contained in the plasma toward the object. The object is a film formed on the work 10. The film formed on the workpiece 10 is a film formed on the workpiece 10 before reaching a desired film thickness, specifically, a compound film on the workpiece 10 processed by the film processing unit 50 or a film on the workpiece 10 formed by the film forming processing unit 40. In other words, the transport unit 30 circularly transports the workpiece 10 so that the workpiece 10 passes through the film formation processing unit 40, the film processing unit 50, and the ion irradiation unit 60 irradiates ions onto the compound film on the workpiece 10 processed by the film processing unit 50. Alternatively, when the respective sections 40, 50, 60 are arranged in the order of the film formation processing section 40, the ion irradiation section 60, and the film processing section 50 in the conveying direction of the conveying section 30, the conveying section 30 conveys the workpiece 10 in a circulating manner so that the workpiece 10 passes through the film formation processing section 40, the ion irradiation section 60, and the film processing section 50, whereby the ion irradiation section 60 irradiates ions on the film on the workpiece 10 formed by the film formation processing section 40. The ion irradiation section 60 includes a plasma generator including a cylindrical electrode 61, a shield 64, an RF power supply 66, and a process gas introduction section 65.

As shown in fig. 3, the ion irradiation section 60 includes a cylindrical electrode 61 provided from the upper portion to the inside of the chamber 20. The cylindrical electrode 61 has a square cylindrical shape, and has an opening 61a at one end and is closed at the other end. The cylindrical electrode 61 is attached to the opening 21a provided in the top surface of the chamber 20 via an insulating member 62 so that one end having the opening 61a faces the turntable 31. The sidewall of the cylindrical electrode 61 extends toward the inside of the chamber 20.

At an end of the cylindrical electrode 61 opposite to the opening 61a, a flange 61b is provided to protrude outward. The insulating member 62 is fixed between the flange 61b and the edge of the opening 21a of the chamber 20, thereby maintaining the inside of the chamber 20 airtight. The insulating member 62 is not limited to a specific material as long as it has insulating properties, and may include, for example, a material such as Polytetrafluoroethylene (PTFE).

The opening 61a of the cylindrical electrode 61 is disposed at a position facing the conveyance path L of the turntable 31. The turntable 31 serves as a conveying section 30 that conveys the tray 34 on which the workpiece 10 is mounted, and passes through a position facing the opening 61 a. The opening 61a of the cylindrical electrode 61 is larger than the size of the tray 34 in the radial direction of the turntable 31.

As shown in fig. 1, the cylindrical electrode 61 has a fan shape with an outer diameter expanding from the center side in the radial direction of the turntable 31 when viewed in the planar direction. The fan shape as referred to herein refers to the shape of the portion of the fan's fan surface. The opening 61a of the cylindrical electrode 61 is also fan-shaped. The speed at which the tray 34 on the turntable 31 passes through the position facing the opening 61a becomes lower as the speed becomes more toward the center side in the radial direction of the turntable 31, and becomes higher as the speed becomes more toward the outside. Therefore, if the opening 61a is rectangular or square, the time for the workpiece 10 to pass through the position opposite to the opening 61a is different between the center side and the outer side in the radial direction. By expanding the opening 61a from the center side to the outer side in the radial direction, the time for passing through the opening 61a can be fixed, and plasma processing described later can be equalized. However, if the difference in the passing time is such that it does not cause a problem in the product, the difference may be rectangular or square.

As described above, the cylindrical electrode 61 penetrates the opening 21a of the chamber 20, and a part thereof is exposed to the outside of the chamber 20. As shown in fig. 3, a portion of the cylindrical electrode 61 exposed to the outside of the chamber 20 is covered with a case 63. The space inside the chamber 20 is kept airtight by the housing 63. The portion of the cylindrical electrode 61 located inside the chamber 20, i.e., the periphery of the side wall, is covered with a shield 64.

The shield 64 is a sector-shaped square cylinder coaxial with the cylindrical electrode 61, and is larger than the cylindrical electrode 61. The shroud 64 is connected to the chamber 20. Specifically, the shield 64 stands from the edge of the opening 21a of the chamber 20, and the end portion extending toward the inside of the chamber 20 is located at the same height as the opening 61a of the cylindrical electrode 61. The shield 64 functions as a cathode in the same manner as the chamber 20, and thus may include a conductive metal member having low resistance. The shroud 64 may be integrally formed with the chamber 20 or may be mounted to the chamber 20 using a fixed metal fitting or the like.

The shield 64 is provided for stably generating plasma in the cylindrical electrode 61. The side walls of the shield 64 are provided so as to extend substantially parallel to the side walls of the cylindrical electrode 61 with a predetermined gap therebetween. If the gap becomes too large, the capacitance becomes small or plasma generated in the cylindrical electrode 61 enters the gap, so that it is desirable that the gap is as small as possible. However, even if the gap becomes too small, the electrostatic capacitance between the cylindrical electrode 61 and the shield 64 becomes large, which is not preferable. The size of the gap can be appropriately set according to the electrostatic capacitance required for plasma generation. Fig. 3 shows only two radially extending side wall surfaces of the shield 64 and the cylindrical electrode 61, but a gap having the same size as the radially extending side wall surface is provided between the shield 64 and the radially extending side wall surfaces of the cylindrical electrode 61.

Further, a process gas introduction portion 65 is connected to the cylindrical electrode 61. The process gas introduction portion 65 includes a gas supply source, a pump, a valve, and the like of the process gas G3, which are not shown, in addition to the piping. The process gas G3 is introduced into the cylindrical electrode 61 through the process gas introduction portion 65. The process gas G3 may be appropriately changed according to the purpose of the process. For example, the process gas G3 may contain argon, oxygen, or nitrogen, or may contain oxygen or nitrogen in addition to argon.

An RF power supply 66 for applying a high-frequency voltage is connected to the cylindrical electrode 61. A matching box 67 as a matching circuit is connected in series to the output side of the RF power supply 66. An RF power source 66 is also connected to the chamber 20. When a voltage is applied from the power supply 66, the cylindrical electrode 61 functions as an anode, and the chamber 20, the cover 64, the turntable 31, and the tray 34 function as a cathode. That is, the electrode functions as an electrode for reverse sputtering. Therefore, as described above, the turntable 31 and the tray 34 have conductivity and are in contact with each other in an electrically connected manner.

The matching box 67 stabilizes the discharge of the plasma by matching the impedance of the input side and the output side. Further, the chamber 20 or the turntable 31 is grounded. The shield 64 connected to the chamber 20 is also grounded. The RF power supply 66 and the process gas introduction portion 65 are connected to the cylindrical electrode 61 through a through hole provided in the housing 63.

When argon gas is introduced into the cylindrical electrode 61 from the process gas introduction portion 65 as the process gas G3, and a high-frequency voltage is applied to the cylindrical electrode 61 from the RF power supply 66, a capacitively coupled plasma is generated, and the argon gas is plasmized to generate electrons, ions, radicals, and the like. Ions in the generated plasma are irradiated to a film on the work 10 on the way.

That is, the ion irradiation section 60 includes a cylindrical electrode 61 having an opening 61a at one end and introducing the process gas G3 therein, and an RF power supply 66 applying a high-frequency voltage to the cylindrical electrode 61, and the transport section 30 transports the workpiece 10 directly below the opening 61a and passes through the same, thereby introducing ions into the film formed on the workpiece 10 and irradiating the film with ions. In the ion irradiation section 60, a negative bias voltage is applied to the turntable 31 and the tray 34 on which the workpiece 10 is placed in order to introduce ions into the film formed on the workpiece 10.

By using the cylindrical electrode 61 such as the ion irradiation unit 60, ions can be introduced into the thin film to be formed by applying a desired negative bias voltage to the pallet 34 and the turntable 31 on which the workpiece 10 is placed while maintaining the ground potential of the above-described members even without applying a high-frequency voltage to the pallet 34 or the turntable 31. Accordingly, it is not necessary to add a structure for applying a high-frequency voltage to the tray 34 or the turntable 31, and it is easy to design the device in consideration of the area ratio of the electrode serving as the anode to the other member surrounding the electrode serving as the cathode in order to obtain a desired bias voltage.

Therefore, even when film formation and ion irradiation are repeated while moving the workpiece 10 in order to planarize a film formed on the workpiece 10, ions can be introduced into the film formed on the workpiece 10 with a simple structure.

Thus, the film processing section 50 has the following functions: oxygen or nitrogen is plasmatized to generate ions, and the ions are chemically reacted with a film formed on the work 10, thereby generating a compound film. In the film processing section 50, an inductively coupled plasma having a high plasma density is used, and thereby ions in the plasma are efficiently chemically reacted with the film formed on the workpiece 10 by the film forming processing section 40, whereby a compound film can be formed.

The ion irradiation section 60 has the following functions: a negative bias voltage is applied to the turntable 31 and the tray 34 on which the workpiece 10 is placed, and ions are introduced into the film formed on the workpiece 10 to planarize the film. In the ion irradiation section 60, ions are easily introduced into the film formed on the workpiece 10 by using the cylindrical electrode 61, and flattening is performed.

(carry-in/carry-out section)

The loading/unloading section 70 is a device as follows: while maintaining the vacuum state of the chamber 20, the tray 34 loaded with the unprocessed workpieces 10 is carried into the chamber 20 from the outside by a carrying member, not shown, and the tray 34 loaded with the processed workpieces 10 is discharged to the outside of the chamber 20. The loading/unloading section 70 may be of a well-known structure, and therefore, description thereof will be omitted.

(control device)

The control device 80 controls various elements constituting the film forming apparatus 100, such as the exhaust portion 90, the sputtering gas introduction portion 49, the process gas introduction portion 58, the process gas introduction portion 65, the power supply portion 46, the RF power supply 54, the RF power supply 66, and the transport portion 30. The control device 80 is a processing device including a programmable logic controller (Programmable Logic Controller, PLC) or a central processing unit (Central Processing Unit, CPU), and stores a program describing control contents. Specific examples of the control include: the initial exhaust pressure of the film forming apparatus 100, the flow rates of the sputtering gas G1, the process gas G2, and the process gas G3, the introduction time and the exhaust time, the film forming time, the rotation speed of the motor 32, and the like, are set to the applied power of the target 42 and the antenna 53. Further, the control device 80 can cope with various film formation specifications.

(operation)

Next, the overall operation of the film forming apparatus 100 controlled by the control device 80 will be described. Fig. 4 is a flowchart of a process performed by the film forming apparatus 100 according to the present embodiment. First, the pallet 34 on which the workpieces 10 are loaded is sequentially carried into the chamber 20 from the loading/unloading section 70 by the carrying means (step S01). In step S01, the turntable 31 sequentially moves the empty holding sections 33 to the position where the tray 34 is carried in from the loading/unloading section 70. The holding units 33 individually hold the trays 34 carried in by the carrying members. In this way, all the trays 34 on which the workpieces 10 to be film-formed are mounted are placed on the turntable 31.

The interior of the chamber 20 is constantly depressurized by exhausting air from the exhaust port 21 through the exhaust portion 90. The pressure in the chamber 20 is reduced to a predetermined pressure (step S02). Then, the turntable 31 on which the workpiece 10 is mounted rotates to reach a predetermined rotation speed (step S03).

When the rotation of the turntable 31 reaches a predetermined rotation speed, the film formation processing unit 40a starts to operate first, and a silicon film is formed on the workpiece 10 (step S04). That is, the sputtering gas introduction portion 49 supplies the sputtering gas G1 through the gas introduction port 47. The sputtering gas G1 is supplied to the periphery of the target 42 containing a silicon material. The power supply 46 applies a voltage to the target 42. Thereby, the sputtering gas G1 is plasmatized. Ions generated by the plasma collide with the target 42 to eject silicon particles. Silicon particles are deposited on the surface of the workpiece 10 passing through the film formation processing section 40a for each pass, thereby forming a silicon film.

The workpiece 10 on which the silicon film is formed passes through the film formation processing section 40 by the rotation of the turntable 31, goes to the film processing section 50, and oxidizes the silicon film by the film processing section 50 (step S05). That is, the process gas introduction portion 58 supplies the process gas G2 containing oxygen gas through the gas introduction port 56. The process gas G2 containing oxygen is supplied into the process space 59 sandwiched between the window member 52 and the turntable 31. The RF power source 54 applies a high-frequency voltage to the antenna 53. An electric field generated by the antenna 53 through which a high-frequency current flows by application of a high-frequency voltage is introduced into the processing space 59 through the window member 52, and the process gas G2 containing oxygen, which has been supplied into the space, is excited to generate plasma. Further, oxygen ions generated by the plasma collide with the silicon film formed on the workpiece 10, thereby bonding with silicon to convert the silicon film on the workpiece 10 into SiO ₂ And (3) a film.

Formed with SiO ₂ The film workpiece 10 passes through the film processing section 50 by the rotation of the rotary table 31, goes to the ion irradiation section 60, and is subjected to SiO by the ion irradiation section 60 ₂ The film is irradiated with ions (step S06). That is, the process gas introduction portion 65 supplies the process gas G3 containing argon gas through a pipe. The process gas G3 is supplied to a space within the cylindrical electrode 61 surrounded by the cylindrical electrode 61 and the turntable 31. When a voltage is applied to the cylindrical electrode 61 by the RF power supply 66, the cylindrical electrode 61 functions as an anode, and the chamber 20, the shield 64, the turntable 31, and the tray 34 function as a cathode, so that the process gas G3 supplied into the space in the cylindrical electrode 61 is excited to generate plasma. Further, the argon ions generated by the plasma collide with SiO formed on the workpiece 10 ₂ A film, whereby particles are moved toward sparse portions in the film, and the film surface is flattened.

Thus, in step S04 to step SIn 06, the film formation process is performed by the workpiece 10 passing through the process space 41 of the film formation processing section 40a in operation, and the oxidation process is performed by the workpiece 10 passing through the process space 59 of the film formation processing section 50 in operation. Further, the workpiece 10 is passed through the space in the cylindrical electrode 61 of the ion irradiation section 60 in operation to cause SiO formed on the workpiece 10 to be formed ₂ The film is planarized. The meaning of "in operation" is the same as that of the plasma generating operation in which plasma is generated in the processing space of each of the sections 40a, 50, and 60.

The film processing unit 50 may be operated until the workpiece 10, which has been first formed by the film formation processing unit 40a, reaches the film processing unit 50. The operation of the ion irradiation unit 60 may be started before the workpiece 10 subjected to the oxidation treatment by the film treatment unit 50 reaches the ion irradiation unit 60.

SiO of a predetermined thickness on the rotary table 31 ₂ The rotation is continued until the film is formed on the work 10, that is, until a predetermined time obtained in advance by simulation or experiment or the like has elapsed (NO at step S07). In other words, siO is formed to a predetermined thickness ₂ During the period before the film, the workpiece 10 is sequentially circulated through the film forming process unit 40a, the film forming process unit 50, and the ion irradiation unit 60 by the conveying unit 30, and the film forming process (step S04) of depositing silicon particles on the workpiece 10, the oxidation process (step S05) of oxidizing the deposited silicon particles, and the generated SiO by the ion irradiation are sequentially repeated ₂ A planarization process of film planarization (step S06).

When the predetermined time has elapsed (YES in step S07), the operation of the film formation processing section 40a is stopped (step S08). Specifically, the introduction of the sputtering gas G1 by the sputtering gas introduction unit 49 is stopped, and the voltage application to the target 42 by the power supply unit 46 is stopped. Further, when the film formation processing section 40a is stopped, the operations of the film formation processing section 50 and the ion irradiation section 60 may be stopped, and the operations may be restarted until the workpiece 10, which was first formed in the film formation processing section 40b, which is to be formed next, reaches the film formation processing section 50 and the ion irradiation section 60. Further, even if the operation of the film formation processing section 40a is stopped, the operations of the film formation processing section 50 and the ion irradiation section 60 may not be stopped. In this case, the film processing section 50 and the ion irradiation section 60 are operated until the operations of the film formation processing section 40a and the film formation processing section 40b are stopped.

Then, the film formation processing portion 40b starts to operate, and the flattened SiO ₂ A niobium film is formed on the film (step S09). That is, the sputtering gas introduction portion 49 supplies the sputtering gas G1 through the gas introduction port 47. The sputtering gas G1 is supplied to the periphery of the target 42 containing the niobium material. The power supply 46 applies a voltage to the target 42. Thereby, the sputtering gas G1 is plasmatized. Ions generated by the plasma collide with the target 42 to eject niobium particles. Niobium particles are deposited on the surface of the workpiece 10 passing through the film formation processing section 40b for each pass, thereby forming a niobium film.

The workpiece 10 on which the niobium film is formed passes through the film formation processing unit 40b by the rotation of the turntable 31, goes to the film treatment unit 50, and oxidizes the niobium film by the film treatment unit 50 (step S10). That is, as in step S05, the process gas G2 containing oxygen is supplied to the processing space 59 by the process gas introduction portion 58, and a high-frequency voltage is applied to the antenna 53 by the RF power supply 54, so that plasma is generated in the processing space 59. Oxygen ions generated by the plasma collide with the niobium film formed on the workpiece 10, thereby bonding with niobium to convert the niobium film on the workpiece 10 into Nb ₂ O ₅ And (3) a film.

Formed with Nb ₂ O ₅ The film workpiece 10 passes through the film processing section 50 by the rotation of the rotary table 31, goes to the ion irradiation section 60, and Nb is irradiated by the ion irradiation section 60 ₂ O ₅ The film is irradiated with ions (step S11). That is, as in step S06, the process gas G3 containing argon is supplied to the processing space surrounded by the cylindrical electrode 61 and the turntable 31 by the process gas introduction portion 65, and a voltage is applied to the cylindrical electrode 61 by the RF power supply 66, whereby the process gas G3 supplied into the processing space is excited to generate plasma. Further, the argon ions generated by the plasma collide with Nb formed on the workpiece 10 ₂ O ₅ A membrane, whereby particles are moved toward sparse portions of the membrane to cause the membrane toThe surface becomes flat.

Nb at a predetermined thickness of the rotary table 31 ₂ O ₅ The rotation is continued until the film is formed on the work 10, that is, until a predetermined time obtained in advance by simulation or experiment or the like has elapsed (no in step S12). In other words, nb is formed to a predetermined thickness ₂ O ₅ During the period before the film formation, the workpiece 10 is sequentially and continuously circulated through the film formation processing unit 40b, the film formation processing unit 50, and the ion irradiation unit 60 by the conveying unit 30, and the film formation process for depositing niobium particles on the workpiece 10 (step S09), the oxidation process for oxidizing the deposited niobium particles (step S10), and the Nb produced by the ion irradiation are sequentially repeated ₂ O ₅ A planarization process of film planarization (step S11).

When a predetermined time has elapsed (yes in step S12), the operation of the film formation processing section 40b is stopped (step S13). Specifically, the introduction of the sputtering gas G1 by the sputtering gas introduction unit 49 is stopped, and the voltage application to the target 42 by the power supply unit 46 is stopped.

Thus, for example, as shown in fig. 5, steps S04 to S13 are repeated until each film reaches a predetermined number, whereby SiO is alternately laminated on the work 10 ₂ Film 11 and Nb ₂ O ₅ A membrane 12.

If a prescribed amount of SiO is formed ₂ Film and Nb ₂ O ₅ The film formation processing section 40, the film processing section 50, and the ion irradiation section 60 are stopped (step S15). That is, the introduction of the sputtering gas G1, the introduction of the process gas G2 and the process gas G3, and the voltage application by the power supply unit 46, the RF power supply 54, and the RF power supply 66 are stopped. Then, the rotation of the turntable 31 is stopped, and the tray 34 on which the work 10 is placed is discharged from the loading/unloading unit 70 (step S16).

(action)

As described above, the film forming apparatus 100 uses the conveying unit 30 to convey the workpiece 10 in a circulating manner so that the workpiece 10 passes through the film forming processing unit 40, the film processing unit 50, and the ion irradiation unit 60, and thus, siO is conveyed ₂ Film and Nb ₂ O ₅ Film Nb ₂ O ₅ Before the films reach the predetermined thickness, the ion irradiation unit 60 irradiates the films withThe film in the middle of formation is irradiated with ions to relax the irregularities of the film, so that a flat film can be laminated.

That is, when a laminated film is formed by stacking a plurality of films, a portion where particles are sparse and a portion where particles are dense are generated in the film, and irregularities are generated in the film, but in the present embodiment, ions are irradiated to the film having irregularities by the ion irradiation unit 60 during the formation of the film, whereby the particles are moved to the sparse portion in the film, and the film is flattened, so that a flat and fine film having no or less irregularities can be formed. Further, even when another type of film is formed on the film, the ion irradiation unit 60 irradiates ions on the film having irregularities during the film formation, thereby moving particles to a sparse portion in the film and planarizing the film, and thus a flat and fine film having no or less irregularities can be formed.

(Effect)

(1) The film forming apparatus 100 according to the present embodiment is a film forming apparatus for forming a film on a workpiece 10, and includes: a conveying unit 30 having a rotary table 31 for circularly conveying the workpiece 10; a film formation processing section 40 having a target 42 containing a material constituting a film and a plasma generator for plasmatizing a sputtering gas introduced between the target 42 and the turntable 31, the target 42 being sputtered by plasma to form a film on the workpiece 10; and an ion irradiation section 60 for irradiating ions; the transport unit 30 transports the workpiece 10 through the film formation processing unit 40 and the ion irradiation unit 60 while forming the film, and the ion irradiation unit 60 irradiates the film on the workpiece 10 with ions while forming the film.

Thus, a flat film can be formed. That is, the particles ejected from the target 42 are easily deposited on a specific portion of the workpiece 10 by the film formation processing section 40 using sputtering, and irregularities are easily formed in the formed film. In contrast, the ion irradiation unit 60 irradiates ions on the film on the way of formation on the workpiece 10, and the ions collide with the portion protruding from the film, and the portion collapses, and the collapsed portion is accommodated in the surrounding concave portion, whereby the film can be flattened. Further, since the film is further formed on the planarized film by the film formation processing section 40 and is planarized by ion irradiation, the flatness can be improved as compared with the case where only the surface of the planarized film is planarized after the film having a predetermined film thickness is formed.

Furthermore, there are the following modes: in order to suppress irregularities on the surface of a film formed by sputtering, a film formation process is performed while heating a workpiece, whereby thermal energy is applied to sputtered particles on the surface of the workpiece, and the sputtered particles are moved to a portion where the sputtered particles are sparse, so that the surface is flattened. However, in a film forming apparatus of a system in which a workpiece is circularly conveyed by rotation of a turntable and repeatedly passed directly under a film forming unit that performs film formation by sputtering, in order to heat the workpiece on the turntable, it is necessary to heat the entire turntable, which requires a large amount of energy, and the structure of the film forming apparatus becomes complicated. In contrast, in the present embodiment, the workpiece 10 is conveyed by the conveying section 30 so that the workpiece 10 passes through the film formation processing section 40 and the ion irradiation section 60 while the film is being formed, and the film on the workpiece 10 is irradiated with ions by the ion irradiation section 60, so that the film can be flattened without heating the workpiece 10, and the device configuration can be prevented from being complicated, and energy saving can be achieved.

In addition, the present embodiment is a film forming apparatus 100 for forming a film on a workpiece 10, including: a chamber 20 for evacuating the interior; a carrying section 30 provided in the chamber and having a turntable 31 for circularly carrying the workpiece 10 on a circumferential carrying path; a film formation processing section 40 having a target 42 containing a material constituting a film and a plasma generator for plasmatizing a sputtering gas G1 introduced between the target 42 and the turntable 31, the target 42 being sputtered by plasma to form a film on the workpiece 10; the film processing unit 50 includes a tubular body 51 protruding into the inner space of the chamber 20 and opening into the transport path, a window member 52 provided so as to block the opening of the tubular body, a first process gas introduction unit (process gas introduction unit 58) for introducing a first process gas (process gas G2) into a process space 59 formed between the turntable 31 and the tubular body 51, an antenna 53 for generating an electric field in the process space 59 via the window member 52, and a power supply (RF power supply 54) for applying a high-frequency voltage to the antenna 53, and generates inductively coupled plasma in the process space 59 by plasmatizing the first process gas G2 to cause a chemical reaction of the film; and an ion irradiation section 60 having a cylindrical electrode 61 provided with an opening 61a at one end and attached to the chamber 20 so that the opening 61a faces the conveyance path, a second process gas introduction section (process gas introduction section 65) for introducing a second process gas (process gas G3) into the cylindrical electrode 61, and an RF power supply 66 for applying a high-frequency voltage to the cylindrical electrode 61, and irradiating the film with ions generated by plasmatizing the second process gas G3; the transport unit 30 transports the workpiece 10 in a circulating manner so that the workpiece 10 passes through the film formation processing unit 40, the film formation processing unit 50, and the ion irradiation unit 60 irradiates ions on the film formed on the workpiece 10.

Thus, the film formed by the film formation processing section 40 can be chemically reacted by the film formation processing section 50, and planarized by the ion irradiation section 60. The ion irradiation unit 60 includes a second process gas introduction unit for introducing the second process gas G3, a cylindrical electrode 61 provided with an opening 61a at one end and into which the second process gas G3 is introduced, and a power supply (RF power supply 66) for applying a high-frequency voltage to the cylindrical electrode 61, whereby a negative bias voltage can be easily applied even to the workpiece 10 that is moved by the cyclic conveyance. Thus, ions can be introduced into the workpiece 10, and the film on the workpiece 10 can be planarized with high efficiency. On the other hand, in the film processing section 50, the film on the workpiece 10 can be efficiently converted into the compound film by using inductively coupled plasma having a higher plasma density than that generated by the ion irradiation section 60.

As described above, in the film forming apparatus 100 of the present embodiment, the film processing unit 50 and the ion irradiation unit 60 are separated as separate components, and the work 10 is circularly conveyed through the respective components in the film forming processing unit 40, the film processing unit 50, and the ion irradiation unit 60, whereby the process of forming an atomic film thickness, converting to a compound film, and planarizing can be repeated on the work 10. Thus, for example, when an optical film including an oxide film is formed, a film having high flatness and high oxidation efficiency can be laminated, and an optical film having high optical characteristics can be formed.

(2) The transport unit 30 transports the workpiece 10 so that the workpiece passes through the film formation processing unit 40 and the ion irradiation unit 60 alternately. Thus, a film having a predetermined thickness is further formed on the planarized film, and thus a flatter film can be formed.

(3) The film processing unit 50 includes a process gas introduction unit 58 for introducing a process gas G2, and a plasma generator for plasmatizing the process gas, and the film formed by the film forming unit 40 is chemically reacted, and the transport unit 30 transports the workpiece 10 through the film processing unit 50 and then through the ion irradiation unit 60. Thus, the compound film formed on the work 10 can be flattened.

(4) The process gas G2 contains oxygen or nitrogen. Thus, the film deposited on the work 10 can be oxidized or nitrided.

(5) The pressure of the sputtering gas in the film formation processing section 40 is set to 0.3Pa or less. As a result, the reduction in kinetic energy of the target constituent particles due to collision of the target constituent particles ejected from the target 42 with the constituent particles such as atoms and ions in the sputtering gas becomes small, and therefore, a phenomenon occurs in which the target constituent particles reach the workpiece 10 or the film on the surface thereof in a state having relatively large kinetic energy and move on the workpiece 10 or the film on the surface thereof, and as a result, the target constituent particles are accommodated in the concave portions of the film, and the film can be flattened.

(6) The film forming apparatus 100 of the present embodiment includes a plurality of film forming process units 40, and the plurality of film forming process units 40 alternately laminate films having different compositions to form the films on the workpiece 10. Thus, an optical device having an optical film with excellent optical characteristics in which diffuse reflection of light on the film surface is suppressed can be obtained.

(7) The ion irradiation section 60 includes a process gas introduction section 65 for introducing a process gas (second process gas) G3, and a plasma generator for plasmatizing the process gas G3, and irradiates ions in the plasma generated by the plasma generator onto the film. In addition, the process gas G3 contains argon. This causes the argon ions having a large atomic size to collide with the film as an aggregate of particles deposited on the workpiece 10, thereby collapsing the convex portions of the film as a dense portion of the particles, and the collapsed particles are easily accommodated in the concave portions of the film as a sparse portion, so that the film can be easily planarized.

(8) The process gas (second process gas) G3 contains oxygen or nitrogen, or contains argon and oxygen or nitrogen. Thus, when the oxidation or nitridation by the film treatment section 50 is insufficient, the ion irradiation section 60 chemically reacts oxygen ions or nitrogen ions with the film to oxidize or nitrid the film, thereby supplementing the reaction. For example, when the workpiece 10 passes through the film processing section 50 before passing through the ion irradiation section 60, even if oxidation or nitridation is insufficient in the film processing section 50, the oxygen ion or the nitrogen ion is chemically reacted with the film in the ion irradiation section 60 that is passed next to oxidize or nitridize the film, whereby the reaction can be supplemented. When argon is contained in the process gas (second process gas) G3, oxygen atoms and nitrogen atoms may be separated from the oxidized or nitrided film due to collision of argon ions, and oxidation or nitridation of the film may be insufficient. Even in this case, the reaction can be supplemented by oxidizing or nitriding the film by chemically reacting oxygen ions or nitrogen ions with the film again. For example, when the workpiece 10 passes through the film processing section 50 before passing through the ion irradiation section 60, there are cases where: even if oxidation or nitridation is performed in the film processing section 50, oxygen atoms and nitrogen atoms are separated from the oxidized or nitrided film due to collision of argon ions in the ion irradiation section 60, and oxidation or nitridation becomes insufficient. Even in this case, the reaction can be supplemented by oxidizing or nitriding the film by chemically reacting the oxygen ion or the nitrogen ion with the film again in the ion irradiation section 60.

Example (example)

With the film forming apparatus 100 of the present embodiment, siO layers of 22 layers in total were alternately formed on the work 10 under the conditions described in table 1 ₂ Film and Nb ₂ O ₅ A cold light mirror formed by laminating films. The numerical range of the "target application power (W)" in the "film formation processing unit" in table 1 indicates the range of the power to be supplied to each of the three targets 42.

TABLE 1

The cold mirror of example 1 is produced by oxidizing the film of each layer by the film treatment section 50 and then ion-irradiating the film by the ion irradiation section 60. The cold mirror of example 2 was produced under the same conditions as in example 1, except that the flow rate of the sputtering gas G1 supplied to the film formation processing section 40 was set to 50sccm, which was smaller than that of example 1. In other words, the pressure of the sputtering gas in the film formation processing section 40 is 0.5Pa in example 1 and 0.3Pa in example 2. The cold mirror of comparative example 1 was produced without ion irradiation by the ion irradiation unit 60, as compared with example 1.

The whole cross-sections and eight layer portions of the surface layers of example 1, example 2 and comparative example 1 were imaged using a Transmission Electron Microscope (TEM) of H-9500 manufactured by Hitachi High-Technologies, inc.

Fig. 6 (a) to 6 (c) are cross-sectional images of example 1, example 2 and comparative example 1 taken by a Transmission Electron Microscope (TEM), fig. 6 (a) is a cross-sectional image of example 1, fig. 6 (b) is a cross-sectional image of example 2, and fig. 6 (c) is a cross-sectional image of comparative example 1. Fig. 7 (a) to 7 (c) are enlarged cross-sectional images of the eight-layer portions of the surface layers of example 1, example 2 and comparative example 1 in fig. 6 (a) to 6 (c), fig. 7 (a) is a cross-sectional image of example 1, fig. 7 (b) is a cross-sectional image of example 2, and fig. 7 (c) is a cross-sectional image of comparative example 1.

Fig. 9 is a graph showing standard deviations of maximum heights Rz of the respective layers of example 1, example 2, and comparative example 1. The "maximum height" in fig. 8 and 9 refers to the height of the protruding portion closest to the surface of the workpiece 10 with the portion closest to the workpiece 10 in each layer as a reference.

As shown in fig. 6 (a) and 7 (a) and 6 (c) and 7 (c), it can be seen that the films of the respective layers become flat in example 1 as compared with comparative example 1. As shown in fig. 8 and 9, it is clear that in example 1, the average maximum height Rz of each layer was reduced by 38% and the average standard deviation of each layer was reduced by 40% compared with comparative example 1, and thus the film of each layer was flattened. Thus, the difference between example 1 and comparative example 1 is due to the presence or absence of the ion irradiation on the film, and thus, as shown in fig. 6 (a) to 6 (c) to 9, the effect of flattening the film by the ion irradiation can be confirmed both visually and numerically.

As shown in fig. 6 (a) and fig. 7 (a) and fig. 6 (b) and fig. 7 (b), it can be seen that the film of each layer becomes even more planar in example 2 than in example 1. As shown in fig. 8 and 9, it is found that in example 2, the average maximum height Rz of each layer was reduced by 56% and the average standard deviation of each layer was reduced by 63% compared with example 1, and thus the film of each layer was flattened. Thus, since the difference between the example 2 and the example 1 is the difference in the flow rate of the sputtering gas supplied to the film formation processing section 40, that is, the difference in the pressure of the sputtering gas, the effect of further flattening the film by lowering the film formation environment can be confirmed in terms of both the visual aspect and the numerical aspect as shown in fig. 6 (a) to 6 (c) to 9.

Further, in example 1, example 2 and comparative example 1 each include a laminated film having 22 layers, but in fig. 8 and 9, if the maximum height Rz and the standard deviation of the first layer are focused, since both of the maximum height Rz and the standard deviation become smaller than those of comparative example 1 in example 1 and example 2, it was confirmed that the effect of flattening the film by ion irradiation can be obtained not only when the laminated film is formed but also when the single-layer film is formed.

(other embodiments)

The present invention is not limited to the above-described embodiments, and includes other embodiments described below. The present invention also includes a combination of all or any of the above-described embodiments and other embodiments described below. Further, various omissions, substitutions, and changes in the embodiments described above may be made without departing from the scope of the invention, and modifications thereof are also included in the invention.

(1) In the above embodiment, the turntable 31 is rotated counterclockwise in a plan view as shown in fig. 1, but the turntable 31 may be rotated clockwise when the ion irradiation unit 60 irradiates the film being formed with ions from the time of film formation by the film formation processing unit 40 until film formation is performed again by the film formation processing unit 40. That is, the transport unit 30 may be configured to be capable of circulating transport in two directions, and the film processing unit 50 may be disposed adjacent to the ion irradiation unit 60. This enables the order of the chemical reaction by the film processing unit 50 and the planarization process of the film by the ion irradiation unit 60 to be changed.

(2) In the above embodiment, the workpiece 10 is circularly conveyed by the conveying unit 30 in the order of the film formation processing unit 40, the film processing unit 50, and the ion irradiation unit 60, but the film processing unit 50 and the ion irradiation unit 60 may be circularly conveyed in the order of the film formation processing unit 40, the ion irradiation unit 60, and the film processing unit 50 while maintaining the same rotation direction (counterclockwise) as in the above embodiment, with the arrangement order of the film processing unit 50 and the ion irradiation unit 60 reversed. In the former case, as in the above-described embodiment, the film after the chemical reaction by the film processing section 50 may be subjected to ion irradiation to planarize the film. In the latter case, oxygen or nitrogen atoms separated from the compound film by ion irradiation by the ion irradiation unit 60 can be replenished by the film treatment unit 50 passing through next by incorporating oxygen or nitrogen in the treatment space 59 of the film treatment unit 50.

(3) In the above embodiment, the conveyance unit 30 has the turntable 31, but an arm extending radially from the rotation center may be used instead of the turntable 31. In this case, the arm holds the tray 34 or the work 10 for rotation.

(4) The film formation processing section 40, the film processing section 50, and the ion irradiation section 60 may be located on the bottom side of the chamber 20, and the vertical relationship between the film formation processing section 40, the film processing section 50, and the ion irradiation section 60 and the turntable 31 may be reversed. In this case, when the turntable 31 is in the horizontal direction, the surface of the turntable 31 on which the tray 34 is disposed becomes a downward-facing surface, i.e., a lower surface.

(5) The deposition apparatus 100 may be provided with a floor, a ceiling, or a side wall. In the above-described embodiment, the tray 34 is provided on the upper surface of the turntable 31 arranged horizontally, the turntable 31 is rotated in the horizontal plane, and the film forming section 40, the film processing section 50, and the ion irradiation section 60 are arranged above the turntable 31. For example, the arrangement of the turntable 31 is not limited to the horizontal arrangement, and may be the vertical arrangement or the inclined arrangement. The tray 34 may be provided on the opposite surface (both surfaces) of the turntable 31. That is, the direction of the rotation plane of the carrying unit 30 of the present invention may be any direction, and the positions of the film formation processing unit 40, the film processing unit 50, and the ion irradiation unit 60 may be any positions as long as the workpieces 10 held by the tray 34 can be processed by the film formation processing unit 40, the film processing unit 50, and the ion irradiation unit 60.

Claims

1. A film forming apparatus for forming a film on a workpiece, comprising:

a chamber capable of making the inside vacuum;

a conveying part which is arranged in the chamber and is provided with a rotary table for circularly conveying the workpiece on a circumferential conveying path;

a film forming processing section having a target containing a material constituting the film and a plasma generator for plasmatizing a sputtering gas introduced between the target and the turntable, the target being sputtered by plasma to form a film on the workpiece;

a film processing unit having a tubular body protruding into an inner space of the chamber and opening into the transport path, a window member provided so as to block an opening of the tubular body, a first process gas introduction unit for introducing a first process gas into a processing space formed between the turntable and the tubular body, an antenna for generating an electric field in the processing space through the window member, and a power supply for applying a high-frequency voltage to the antenna, and generating inductively coupled plasma in the processing space by plasmatizing the first process gas to cause a chemical reaction of the film; and

An ion irradiation section having a cylindrical electrode provided with an opening at one end and attached to the chamber so that the opening faces the conveyance path, a second process gas introduction section for introducing a second process gas into the cylindrical electrode, and a power supply for applying a high-frequency voltage to the cylindrical electrode, the ion irradiation section irradiating the film with ions generated by plasmatizing the second process gas;

the conveying part circularly conveys the workpiece in a way that the workpiece passes through the film forming processing part, the film processing part and the ion irradiation part,

when passing through the ion irradiation part, the whole surface of the workpiece, which is formed with a film, faces the opening part,

the ion irradiation section irradiates ions on the film on the way of formation on the workpiece.

2. The film forming apparatus according to claim 1, wherein

The transport unit transports the workpiece through the ion irradiation unit after passing through the film processing unit.

3. The film forming apparatus according to claim 1, wherein

The transport unit transports the workpiece through the ion irradiation unit and then through the film processing unit.

4. The film forming apparatus according to claim 2 or 3, wherein

The conveying part is configured in a manner that the circulating conveying in two directions can be performed,

the film treatment section is disposed adjacent to the ion irradiation section.

5. The film forming apparatus according to any one of claims 1 to 3, wherein

The first process gas contains oxygen or nitrogen.

6. A film forming apparatus according to any one of claims 1 to 3, comprising:

a plurality of the film formation processing sections described above,

the plurality of film formation processing sections alternately laminate the films having different compositions to form the film on the workpiece.

7. The film forming apparatus according to any one of claims 1 to 3, wherein

The second process gas contains argon.

8. The film forming apparatus according to any one of claims 1 to 3, wherein

The second process gas contains oxygen or nitrogen, or argon and oxygen or nitrogen.