JPH09296265A - Production of oblique vapor-deposited coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously realize the uniformization of the distribution of coating film thickness, the stabilization of coating film characteristics and vapor deposition at a low temp. by forming vapor-deposited coating film from >= two layers, vapor- depositing substrates arranged at a distance equal to each other from a vapor depositing source, uniformly forming coating film so as to regulate the total thickness of the vapor deposition to be thick one, and thereafter regulating its coating film thickness to desired one by a dry etching method. SOLUTION: A vapor depositing source and a substrate are arranged in a vacuum tank, and the material flown from the vapor depositing source is obliquely vapor- deposited on the surface of the substrate to produce a double refraction sheet. In this method, the substrate 1 is coated with a matching coat 2 increasing its adhesion, which is next vapor-deposited with vapor-deposited coating film 3 having double refraction by the 1/2 of the desired phase angle, and after that, vapor-deposited coating film 4 having double refraction is vapor-deposited in such a manner that it is made approximately larger than the desired phase angle. Since, in the vapor-deposited coating film, the coating thickness and the phase angle lie in proportional relation, the surface of the vapor-deposited coating film 4 is subjected to dry etching 20 to the desired coating thickness. Then, it is coated with antireflection coating film 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for forming an obliquely deposited film.

[0002]

2. Description of the Related Art Conventionally, a method for producing an obliquely vapor-deposited film is disclosed in Japanese Patent Laid-Open No.
The thing described in the 3-132203 publication is known.

FIG. 2 shows a schematic sectional view of a conventional process for manufacturing an obliquely evaporated film. In FIG. 2, the substrate 7
The matching coat 8 vapor-deposited on the substrate is arranged with the substrate surface inclined with respect to the flying direction of the vapor deposition material (dielectric material),
The first layer of vapor-deposited film 9 formed as a columnar structure that grows obliquely from the substrate surface, the second layer of vapor-deposited film 10 formed after reversing the substrate by 180 °, and the antireflection film 11 are formed. There is. The vapor deposition film has a birefringence effect on incident light,
For example, it is used as an optical functional element element such as a quarter wavelength (λ) plate.

FIG. 6 shows an example of a conventional apparatus for manufacturing an obliquely vapor-deposited film, which is a substrate 12 held by a substrate holder 18.
Then, the electron gun 13 is placed on the evaporation source 14 and the vapor deposition material is vapor deposited at the vapor deposition angle θ to obtain a birefringent film.

FIG. 7 shows a rotary drum 1 of a conventional continuous vapor deposition apparatus.
The substrate is attached to 9 and vapor deposition is carried out by rotary feeding every time a desired film thickness is obtained. 8 is a side view of the device of FIG.
When 2 reaches the desired film thickness, the drum 19 rotates to indicate the state of starting the vapor deposition of the next substrate.

[0006]

In the method for manufacturing the obliquely vapor-deposited film as described above, particularly in a CD (compact disc), a DVD (digital video disc), etc., a laser having a constant wavelength is used to form a birefringent film. Since minute changes lead to deterioration of characteristics, humidity characteristics, temperature characteristics, and performance with no change in life are required.

In the above-mentioned conventional method, it is difficult to increase the size of the vacuum apparatus, the working time is long, the film thickness is not uniform, the film properties are not stable from lot to lot, and the properties of the substrate are impaired. It has a drawback that it is not suitable for vapor deposition at low temperatures.

That is, in this method, the film thickness is thicker near the vapor deposition source and thinner at the distant source, and the vapor deposition is performed by reversing each substrate at the midpoint of the desired film thickness in order to make the film thickness uniform. The film thickness is made uniform.

The oblique vapor deposition film does not always have the same film thickness and performance due to various factors such as vapor deposition source, substrate surface condition, substrate temperature, and degree of vacuum.

Since the characteristics of the vapor deposition source are not stable, the film characteristics were measured during film formation and the remaining film thickness was determined based on the measured values. However, due to the nonuniformity of the film thickness and the instability of the film characteristics, there was variation in the characteristics within the substrate. It was great. Therefore, there is a problem that the characteristics are not stable depending on the degree of film formation.

In the vapor deposition of oxides such as Ta2O5, a moisture adsorbing film chemically bonded to the surface is formed by exposing the film to air in the formed film, and the characteristics of the film are unstable when another film such as an antireflection film is overlaid. There was a problem that changed with the passage of time.

Further, since the obliquely vapor-deposited film has restrictions on the film forming conditions for making the film thickness and the characteristics in the substrate uniform, it is difficult to vapor-deposit a large number of substrates at the same time.

The present invention provides a method for producing an obliquely vapor-deposited film, which can realize uniform film thickness distribution of the obliquely vapor-deposited film, stabilization of film characteristics, and vapor deposition at a low temperature at the same time. It was done for the purpose.

[0014]

In order to solve this problem, in the method for manufacturing an obliquely evaporated film of the present invention, an evaporation source and a substrate are arranged in a vacuum chamber, and the material flying from the evaporation source is placed on the substrate surface. According to a method of manufacturing a birefringent plate by obliquely vapor depositing, the vapor deposition film is composed of at least two layers and is composed of a substrate arranged at an equal distance from a vapor deposition source during vapor deposition, and a total vapor deposition thickness is desired. After the film is uniformly formed thicker than the film thickness, the film is removed to a desired film thickness by a dry etching method.

As a result, the film thickness distribution of the obliquely evaporated film can be made uniform, and the unstable surface film formed on the surface can be removed, and the film characteristics can be stabilized at the same time.

During deposition, the deposition angle θ is kept constant with respect to the deposition source, and a large number of substrates arranged equidistantly from the deposition source are revolved around the axis of the normal line of the deposition source to perform continuous deposition, thereby simultaneously processing a large number of substrates. Is performed to improve the efficiency of the production of the obliquely deposited film.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, an evaporation source and a substrate are arranged in a vacuum chamber, and a material flying from the evaporation source is obliquely vapor-deposited on the surface of the substrate to form a birefringent plate. In the above method, the vapor-deposited film is composed of at least two layers, and a substrate placed at an equal distance from the vapor deposition source during vapor deposition is vapor-deposited so that the total vapor deposition thickness is thicker than a desired film thickness and uniformly formed. After that, the film is removed to a desired film thickness by a dry etching method, and the substrate surface temperature during vapor deposition is 1
It is preferably 80 ° C or lower. This not only suppresses the film thickness variation within the wafer, but also removes the unstable layer and stains generated during the film formation, and can precisely fine-tune the characteristics of the optical film.

According to a second aspect of the present invention, the evaporation source and the substrate are arranged in a vacuum chamber, and the material flying from the evaporation source is obliquely vapor-deposited on the surface of the substrate to produce a birefringent plate. The vapor-deposited film is composed of at least two layers, and the substrate disposed equidistant from the vapor-deposition source during vapor-deposition is revolved around the axis of the normal line of the vapor-deposition source to perform the vapor-deposition at all times. Method, and the peripheral speed is preferably 30 m / min or less. This has the effect of eliminating non-uniformity of the distribution of flying particles from the target in the vapor deposition layer within the device.

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows a manufacturing process of a vapor deposition film according to an embodiment of claim 1 of the present invention.
Reference numeral 1 is a substrate, 2 is a matching coat, 3 is a first layer vapor deposition film, 4 is a second layer vapor deposition film, 5 is a portion to be removed by dry etching, and 6 is an antireflection film.

Regarding the improvement of the method for forming the obliquely vapor-deposited film configured as described above, the process thereof will be described below.

First, a transmissive optical substrate 1 is coated with a matching coat 2 for improving adhesion, and then a first-layer vapor-deposited film 3 having birefringence (generally Ta2O5, Ti is used).
It is known that the birefringence characteristic is obtained by obliquely evaporating O2 or the like), and 1/2 of a desired phase angle is vapor-deposited, and then the second vapor deposition film 4 having the birefringence is vapor-deposited. Then, vapor deposition is performed so as to be substantially larger than the desired phase angle. When the phase angle of the two-layer oblique vapor deposition film is measured, since the film is formed larger than the desired phase angle, the phase angle larger than the desired value can be obtained. Since the vapor deposition film has a proportional relationship between the film thickness and the phase angle, the surface of the vapor deposition film 4 is dry-etched 20 to a desired film thickness. After that, the antireflection film 6 is coated.

(Embodiment 2) FIG. 3 is a layout view of a vacuum apparatus according to an embodiment of claim 2. In FIG. During the vapor deposition, the substrate kept at 70 ° and equidistant to the vapor deposition source is revolved around the axis of the vapor deposition source in the direction perpendicular to the vapor deposition source to perform the vapor deposition at all times. FIG. 4 is a diagram showing the variation in the film thickness inside the apparatus when the substrate is revolved around the axis of the vapor deposition source in the direction perpendicular to the axis, and the variation 16 is 7% when the substrate is not revolved.
When orbiting, the film thickness variation 17 is 1% or less. In this case, the revolution speed is 15 m / min, and the deposition rate is
0.12 μm / min. FIG. 5 is a diagram showing the arrangement of substrates in the case of revolving, and is a view of the arrangement of FIG. 7 viewed from the vapor deposition source side, in which the base material is arranged at an equal distance from the vapor deposition source.

As described above, according to the second embodiment, even if the obliquely vapor-deposited film is revolved under a certain condition, the non-uniformity of the position in the device is eliminated, and a large number of devices can be arranged in the device. It becomes possible and simultaneous continuous film formation will be possible.

Further, although tantalum oxide and titanium oxide are used as the vapor deposition material in the above-mentioned embodiment, as the vapor deposition material, oxides such as Ce02, Al2O3 and WO3 can be used as in the conventional case. The dry etching method for removing the obliquely vapor-deposited film in the above embodiment refers to ion milling, reactive milling, reverse sputtering, and the like.

[0025]

As described above, according to the first embodiment of the present invention, the uniform film thickness distribution and the stable film characteristics of the obliquely evaporated film having birefringence can be obtained at the same time, and the desired phase angle can be obtained. Therefore, the film can be formed with high accuracy.

A laser with a constant wavelength, such as a CD (compact disc) or a DVD (digital video disc).
In the case of an optical component in which a minute change in the birefringent film leads to deterioration of characteristics, performance that does not change with humidity characteristics, temperature characteristics, and life is required. The plate has sufficient characteristics for CD and DVD and can contribute to downsizing of the pickup.

Further, according to the second embodiment, it is possible to arrange a large number of substrates in the apparatus, and it is possible to obtain an advantageous effect that it is possible to manufacture a large amount of oblique vapor deposition films having birefringence.

[Brief description of drawings]

1A to 1F are schematic cross-sectional views showing a manufacturing process of an obliquely evaporated film according to a first embodiment of the present invention.

2 (a) to (e) are manufacturing process diagrams of a conventional vapor deposition film.

FIG. 3 is a layout diagram of a vacuum device according to a second embodiment of the present invention.

FIG. 4 is a film thickness distribution diagram in the apparatus during revolution of the present invention.

FIG. 5 is a substrate layout view seen from the evaporation source side in the vacuum device of FIG.

FIG. 6 is a diagram showing an example of a conventional apparatus for manufacturing a diagonally evaporated film.

FIG. 7 is a diagram showing an example of a conventional continuous vapor deposition apparatus.

FIG. 8 is a side view of the device of FIG.

[Explanation of symbols]

 1,7 Substrate 2,8 Matching coat 3,9 First layer of oblique vapor deposition film 4,10 Second layer of oblique vapor deposition film 5 Removal portion 6,11 Antireflection film 12 Substrate 13 Electron gun 14 Evaporation source 15 Substrate Holding member 16 Film thickness distribution when not revolving 17 Film thickness distribution when revolving 18 Substrate holder-19 Rotary drum 20 Dry etching 21 Exhaust pump

Claims (2)

[Claims] 1. An evaporation source and a substrate are arranged in a vacuum chamber, and a material flying from the evaporation source is obliquely deposited on the surface of the substrate,
In the method of manufacturing a birefringent plate, the vapor deposition film is composed of at least two layers, and a substrate placed at an equal distance from the vapor deposition source during vapor deposition is vapor-deposited to make the total vapor deposition thickness thicker than a desired film thickness. A method for manufacturing an obliquely vapor-deposited film, characterized in that after the film is formed, it is removed to a desired film thickness by a dry etching method. 2. An evaporation source and a substrate are arranged in a vacuum chamber,
In a method for manufacturing a birefringent plate by obliquely vapor-depositing a material coming from an evaporation source on a substrate surface, the vapor-deposited film is composed of at least two layers, and a substrate placed at an equal distance from the vapor-deposition source during vapor deposition is used. A method for producing an obliquely vapor-deposited film, which is characterized in that continuous vapor deposition is performed by revolving around a vertical axis of a vapor deposition source.