JPH06116708A - Method and apparatus for production of film for laser - Google Patents

Abstract

PURPOSE:To prevent the degradation in the quality of a thin film by residual dust by carrying a substrate into a first vacuum chamber, irradiating this substrate with an ion beam and depositing a thin film by evaporation in a second vacuum chamber. CONSTITUTION:A sluice valve 2b of a carry-in chamber 2 is opened to carry the substrate W1 into this chamber. This sluice valve 2b is closed and the carry-in chamber 2 is evacuated. While the substrate W1 is moved back and forth, the film forming surface of the substrate W1 is irradiated with the ion beam to clean the film forming surface and to remove the dust, etc., sticking thereto. The substrate W1 is then carried into a film forming chamber 1 under vacuum evacuation or heating. After the film forming chamber 1 is evacuated to a prescribed vacuum pressure, the vapor is generated from an evaporating chamber 1a and is stuck on the film forming surface of the substrate to form the thin film. A second gate valve 1d is thereafter opened and the substrate W1 is transferred into an ejection chamber 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser film manufacturing method and apparatus for manufacturing a thin film such as an antireflection film, a reflection increasing film or a polarizing film of an optical system using laser light.

[0002]

2. Description of the Related Art An antireflection film for preventing reflection of laser light, a reflection increasing film for promoting reflection, a polarizing film for polarizing laser light, etc. are manufactured by vapor deposition in a vacuum chamber.

The film forming method by vapor deposition in a vacuum tank is a batch process using one vacuum tank, or one vacuum tank is provided on each side of the vacuum tank for film formation, and the substrate is loaded, unloaded, and heated. , An in-line process that improves productivity by continuously performing pre- and post-treatments such as cooling in one direction, and a vacuum that performs pre- and post-treatments such as loading and unloading and heating and cooling of substrates only on one side of the vacuum tank for film formation. The one in which the productivity of the batch process is improved by providing one tank has been developed.

[0004]

However, according to the above conventional technique, when each vacuum chamber is evacuated, the residual dust in the vacuum chamber is sucked together with the exhausted gas and flows in the vacuum chamber. However, it may adhere to the surface of the substrate, and as a result, the quality of the thin film to be produced may deteriorate.In particular, the vacuum deposition chamber cannot completely remove the residual deposits, and exhaust or vent dust on the substrate. Has a high probability of sticking. Such dusts are a major cause of lowering the durability of the thin film against laser light (hereinafter referred to as “laser resistance”) when manufacturing a thin film that is irradiated with laser light.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and it is possible to prevent the deterioration of the quality of the thin film due to the residual dust carried by the gas flowing during the exhaust of the vacuum chamber. An object of the present invention is to provide a method and an apparatus for producing a laser film that can be used.

[0006]

In order to achieve the above object, the method of the present invention comprises a step of loading a substrate having a film-forming surface into a first vacuum chamber and evacuating the first vacuum chamber. The first vacuum chamber is evacuated and then the first vacuum chamber is evacuated after the first vacuum chamber is evacuated. The film forming surface of the substrate of the vacuum chamber is irradiated with an ion beam.

Further, a step of carrying in a substrate having a film-forming surface into a first vacuum chamber and evacuating the first vacuum chamber, and a substrate of the evacuated first vacuum chamber into a second vacuum chamber. Second to carry in
From the step of evacuating the vacuum chamber, the step of irradiating the film forming surface of the substrate of the evacuated second vacuum tank with an ion beam, and the step of depositing a thin film on the film forming surface of the substrate irradiated with the ion beam. It is characterized by

[0008]

According to the method of the present invention, the substrate is evacuated from atmospheric pressure in the first vacuum chamber in which film formation is not performed and the amount of residual dust is minimized, and the second vacuum chamber in which film formation is performed in vacuum. By moving the substrate, it is possible to avoid exhaustion from the atmosphere in the vacuum chamber for forming a film with a large amount of residual dust. Further, the atmospheric pressure venting when the substrate is carried out is also performed in the vacuum chamber in which the first or third film formation is not performed, so that the dust adhesion to the substrate can be avoided. Furthermore, the substrate surface is etched by irradiating the substrate with an ion beam after vacuum evacuation and before film formation, and the residual abrasive during polishing, process-altered layer, residual substances during cleaning, dust adhered during evacuation, etc. are removed. It has a clean surface that is very close to the characteristics of the base material,
By forming a film on this surface in a continuous vacuum, a thin film element with a small amount of impurities and dust can be manufactured.

[0009]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram for explaining the first embodiment. The film forming apparatus E ₁ of this embodiment is a second vacuum chamber having an evaporation source 1a heated by an electron beam. It has a film chamber 1 and a loading chamber 2 and an unloading chamber 3 which are first vacuum chambers communicating with the film chamber 1. In the film forming chamber 1, a disk-shaped substrate holder 1b is arranged above the evaporation source 1a in the drawing.
b is rotated about its central axis by a rotating device (not shown). A first gate valve 1c is provided between the film forming chamber 1 and the carry-in chamber 2, and a second gate valve 1d is provided between the film forming chamber 1 and the carry-out chamber 3.
The film forming chamber 1, the carry-in chamber 2 and the carry-out chamber 3 are evacuated by individual vacuum lines (not shown). The carry-in chamber 2 has an opening 2a at one end, and the opening 2a is opened and closed by a sluice valve 2b. An opening 3a is provided at one end of the carry-out chamber 3, and the opening 3a is opened and closed by a sluice valve 3b. The carry-in chamber 2 has a heater 2c for preheating,
Further, the carry-out chamber 3 has a heater 3c for adjusting the cooling rate.
Further, the substrate W ₁ is loaded in the loading chamber 2 and the loading chamber 3 respectively.
A rail (not shown) for moving the film toward and away from the film forming chamber 1 is provided. The carry-in chamber 2 has an ion gun 4 which is an ion beam generating means below the moving path of the substrate W ₁ moving along the rail in the drawing. The ion gun 4 is a Kaufman type linear type having a grid size of 25 mm × 400 mm The stand-by side effective width is 700 mm, and the ion current density distribution is within ± 5%.

Loading and unloading of the substrate W ₁ and film formation are performed as follows.

First, the sluice valve 2b of the carry-in chamber 2 is opened, the substrate W ₁ is carried into the carry-in chamber 2 with the film deposition surface for depositing a thin film facing downward, and the sluice valve 2b is closed and then the carry-in chamber 2b. Evacuate 2. When the loading chamber 2 reaches a predetermined vacuum pressure, the substrate W
While reciprocating along _a rail, by irradiating an ion beam from the ion gun 4 toward the deposition surface of the substrate W _1, to remove the dust that was cleaned and adhesion of the deposition surface of the substrate W _1. The distance between the grid of the ion gun 4 and the film formation surface of the substrate W ₁ irradiated with the ion beam is 20.
0 mm, the reciprocating speed of the substrate W ₁ is 10 to 100 mm /
min is desirable.

The depth of etching by the ion beam of the ion gun 4 depends on the number of times the substrate W ₁ is reciprocated and its speed,
It can be adjusted by the beam current of the ion gun 4 and the acceleration voltage. As an example, the etching depth is 200
Å The beam current of the ion gun 4 should be 20
It is sufficient that the current is 0 mA, the acceleration voltage is 1000 V, the reciprocating speed of the substrate W ₁ is 100 mm / min, and the number of reciprocating movements is 4.

Next, if necessary, the heater 2 in the carry-in chamber 2
After the substrate W ₁ is preheated by c, the first gate valve 1c is opened and the substrate W ₁ is evacuated and carried into the film forming chamber 1 under heating and held in the substrate holder 1b in vacuum. After the film forming chamber 1 is evacuated to a predetermined vacuum pressure, while the substrate holder 1b is rotated, vapor is generated from the evaporation source 1a and attached to the film forming surface of the substrate W ₁ . When a thin film having a predetermined thickness is formed on the film-forming surface of the substrate W ₁ , the second gate valve 1
After opening d, the substrate W ₁ is unloaded to the unloading chamber 3, the second gate valve 1d is closed, and then, if necessary, it is gradually cooled to a predetermined temperature by the heater 3c. Next, the sluice valve 3 in the unloading chamber 3
Open b, take out the substrate W ₁ and send it to the next step.

As described above, there are three chambers of the carry-in chamber, the film-forming chamber, and the carry-out chamber.
By providing two vacuum layers and performing etching with an ion beam before film formation, the amount of impurities mixed in the thin film element can be significantly reduced. As an example, when the backscattered light of the highly reflective film (about 30 layers) for the 3rd harmonic of the Nd: YAG laser manufactured by the above method is observed with a stereoscopic microscope at about 110 times, the amount of dust is 1 / It was reduced to 10 or less, and the laser proof strength was improved about twice or more.

FIG. 2 is a schematic diagram for explaining the second embodiment. The film forming apparatus E ₂ of this embodiment is a second vacuum chamber having an evaporation source 11a heated by an electron beam. A chamber 11 and a loading / unloading chamber 12 that is a first vacuum chamber communicating with the chamber 11 are provided. The film forming chamber 11 includes a disk-shaped substrate holder 11b above the evaporation source 11a in the figure.
b is rotated about its central axis by a rotating device (not shown). A gate valve 11c is provided between the film forming chamber 11 and the carry-in / out chamber 12, and the film forming chamber 11 and the carry-in / out chamber 12 are exhausted by individual vacuum lines (not shown).
The loading / unloading chamber 12 has an opening 12a at one end, and the opening 12a is opened and closed by a sluice valve 12b. In addition, the carry-in / out room 12
Has a heater 12c for preheating and cooling rate adjustment. Further, the loading / unloading chamber 12 is provided with rails (not shown) for moving the substrate W ₂ back and forth toward the film forming chamber 11.

The evaporation source 11a of the film forming chamber 11 and the substrate holder 1
An ion gun 14 that is an ion beam generating means that reciprocates in parallel to the film formation surface of the substrate held by the substrate holder 11b is arranged between the 1b. The ion gun 14 is formed by arranging three linear sources having a grid size of 25 × 400 mm, and has an ion current density distribution within ± 5% within an effective width of 1000 mm.

The loading and unloading of the substrate W ₂ and the film formation are performed as follows.

First, the sluice valve 12b of the loading / unloading chamber 12 is opened, the substrate W ₂ is loaded into the loading / unloading chamber 12 with the deposition surface for depositing a thin film facing downward, the sluice valve 12b is closed, and then the loading / unloading chamber 12 is closed. Evacuate 12. After the loading / unloading chamber 12 reaches a predetermined vacuum pressure, the substrate W ₂ is preheated by the heater 12c if necessary, and the gate valve 11c is opened to load the substrate W ₂ into the film forming chamber 11 and the substrate holder 11b. To hold. After the film forming chamber 11 is evacuated to a predetermined vacuum pressure, the film forming surface of the substrate W ₂ is irradiated with an ion beam while reciprocally moving the ion gun 14, and the film forming surface is approximately 1000 to 2000 Å.
The substrate surface is cleaned by etching. During this time, by rotating the substrate holder 11b, the etching depth can be made more uniform.

Next, while rotating the substrate holder 11b, vapor is generated from the vapor deposition source 11a and adheres to the film formation surface of the substrate W ₂ . When a thin film having a predetermined film thickness is formed on the film formation surface of the substrate W _2, the gate valve 11c is opened to move the substrate W ₂ to the carry-in / out chamber 12, and after gradual cooling, the sluice valve 12b is opened to open the substrate W.
_Take out _two .

If the substrate is large and has a diameter of 200 mm or more and is thick, the ion gun 14 is used for etching, and then the substrate W ₂ is returned to the loading / unloading chamber 12 and preheated by the heater 12c. It is desirable to shorten the manufacturing time by heating the film forming chamber 11 as well.

In this embodiment, in particular, the diameter is 300 mm to 150 mm.
It is suitable for forming a film on a large substrate of 0 mm.

[0023]

Since the present invention is configured as described above, it has the following effects.

It is possible to prevent the quality of the thin film from deteriorating due to dust or the like adhering to the film forming surface of the substrate during evacuation of the vacuum chamber. As a result, a high quality thin film can be manufactured. Particularly, in the case of a thin film used for preventing reflection of laser light, increasing reflection, or deflecting the laser light, its laser resistance can be greatly improved.

In addition to the vacuum layer for film formation, a vacuum layer for exhausting air from the atmosphere with a small amount of residual dust and a vacuum layer for venting to atmospheric pressure are provided, and the substrate is moved to the vacuum layer for film formation in vacuum. By doing so, it is possible to avoid exhausting and venting from atmospheric pressure in the film forming vacuum layer having a high probability of dust adhesion to the substrate.

Further, by etching the surface of the substrate with an ion beam after evacuation and before film formation, the previous step (polishing,
The thin film element with a small amount of impurities and dust is produced by removing impurities and dust that have been introduced and adhered by cleaning, exhausting, etc., and forming a film in the same vacuum.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a first embodiment.

FIG. 2 is a schematic diagram illustrating a second embodiment.

[Explanation of symbols]

 1, 11 Film forming chamber 1a, 11a Evaporation source 1c, 1d, 11c Gate valve 2 Loading chamber 2b, 3b, 12b Gate valve 3 Loading chamber 4,14 Ion gun 12 Loading / unloading chamber

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hidehiko Fujimura, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inori, Atsushi Ishikura 3-30-2 Shimomaruko, Ota-ku, Tokyo Non-Incorporated (72) Inventor Koji Sawamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Kunio Yoshida 2-3-3, 2-3-2 Torii Nozen, Settsu City, Osaka Prefecture

Claims (8)

[Claims] 1. A step of loading a substrate having a film-forming surface into a first vacuum chamber and evacuating the first vacuum chamber; and a step of evacuating the substrate of the first vacuum chamber into a second vacuum chamber. A step of carrying in and depositing a thin film on the film-forming surface, and irradiating an ion beam onto the film-forming surface of the substrate of the evacuated first vacuum tank after the first vacuum tank is evacuated. A method for producing a film for a laser. 2. A step of loading a substrate having a film-forming surface into a first vacuum chamber and evacuating the first vacuum chamber; and a step of evacuating the substrate in the first vacuum chamber into a second vacuum chamber. The step of carrying in and evacuating the second vacuum chamber, the step of irradiating the film forming surface of the substrate of the evacuated second vacuum tank with an ion beam, and the step of irradiating the film forming surface of the substrate irradiated with the ion beam. A method for manufacturing a laser film, comprising a step of depositing a thin film. 3. The method for manufacturing a laser film according to claim 1, wherein the ion beam and the substrate are relatively reciprocally moved. 4. The method for producing a laser film according to claim 1, wherein the substrate is irradiated with an ion beam at room temperature, and the substrate is preheated in the first vacuum chamber. 5. A first vacuum chamber for passing a substrate having a film-forming surface, and a second vacuum chamber for depositing a thin film on the film-forming surface of the substrate which has passed through the first vacuum chamber, the first vacuum chamber comprising: An apparatus for producing a film for a laser, comprising an ion beam generating means for irradiating an ion beam on a film forming surface of a substrate passing through the film. 6. A first vacuum chamber for passing a substrate having a film-forming surface, and a second vacuum chamber for depositing a thin film on the film-forming surface of the substrate that has passed through the second vacuum chamber. An apparatus for producing a film for a laser, comprising an ion beam generating means for irradiating an ion beam on a film forming surface of a substrate on which a thin film is deposited. 7. The film manufacturing apparatus for a laser according to claim 5, further comprising a moving mechanism for relatively reciprocating the ion beam and the substrate. 8. The film manufacturing apparatus for a laser according to claim 7, wherein the moving mechanism of the ion beam and the moving mechanism of the substrate are moved by the same rail.