JPH09302466A - Manufacturing equipment of double refraction film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that retardation of a targeted double refraction film can not be obtained with excellent reproducibility only by controlling the film thickness because the double refraction is fluctuated by the vapor deposition batch in manufacturing the double refraction film through the diagonal vapor deposition of the metallic oxide in a vacuum vapor deposition equipment. SOLUTION: The straight-polarized laser beam is introduced in one direction from the outside of a vacuum vapor deposition chamber 1, transmitted through a transparent substrate 2 which is diagonally vapor-deposited, and the laser beam is perpendicularly reflected by a total reflection mirror 12 and again transmitted through the transparent substrate 2, the returned laser beam is spectroscopically analyzed by a half mirror 5, and the retardation is monitored by combining a 1/4 wavelength plate 7 with a polarizing filter 8 making use of the Senarmont method. The rotational angle of the polarizing filter is set from the targeted retardation value, and when the output voltage from a light receiving element 9 is minimized during the vapor deposition, a judgment of the targeted retardation is made, and the vapor deposition is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing apparatus for manufacturing a birefringent film by oblique evaporation in the technical field of vacuum evaporation, and in particular, it is possible to monitor retardation of a birefringent film during evaporation. The present invention relates to a refraction film manufacturing apparatus.

[0002]

2. Description of the Related Art In recent years, a quarter-wave plate is used as an optical component in a laser type optical pickup technique such as a compact disc reproducing device. This quarter-wave plate used to be manufactured by processing quartz, but as a new technology, T
A manufacturing method of forming a birefringent film by oblique vapor deposition of a metal oxide such as a2O5 is disclosed in JP-A-59-49508. In order to ensure the reproducibility of film formation in the vapor deposition apparatus, a film thickness monitor is installed to stop the apparatus at the target film thickness while measuring the film thickness during vapor deposition. Conventionally, this film thickness monitor is generally performed by crystal vibration or optical interference.

[0003]

However, when a metal oxide is obliquely vapor-deposited to produce a birefringent film, the same film thickness may be caused due to contamination in the vapor deposition apparatus, the state of the vapor deposition source, the vapor deposition vacuum degree, etc. Even if there is, the retardation of the birefringent film fluctuates. Therefore, the target retardation birefringent film cannot be accurately manufactured by the conventional film thickness control method of the vapor deposition apparatus, which is a major cause of a decrease in manufacturing yield.

The present invention has been made for the purpose of improving the reproducibility of the conventional oblique deposition and improving the yield.

[0005]

In order to solve the above problems, the apparatus for producing a birefringent film of the present invention, when the birefringent film is vapor-deposited by oblique vapor deposition, linearly polarized light from a laser light source, After passing through the vapor-deposited transparent substrate, the light is reflected vertically by a non-polarization total reflection mirror, again transmitted through the transparent substrate, and the returned light is split by a half mirror, using the Senarmont method. The retardation of the birefringent film formed on the substrate can be monitored, and the vapor deposition can be completed at the target retardation.

According to the present invention, the birefringent film having the desired retardation can be manufactured with high accuracy, and the manufacturing yield can be improved.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is an apparatus for manufacturing a birefringent film by obliquely vapor-depositing a metal oxide, and when a birefringent film is vapor-deposited, a laser light source is used. After the linearly polarized light is transmitted through the vapor-deposited transparent substrate, the light is reflected vertically by the total reflection mirror and again transmitted through the transparent substrate, and the returning light is split by the half mirror, and the Senarmont method is applied. Utilizing this, the retardation of the substrate birefringent film during vapor deposition can be directly monitored, and there is a function to stop the vapor deposition.Since vapor deposition can be stopped when the birefringent film with the desired retardation is formed, it is possible to avoid Even if there is a variation factor, since the retardation of the actual birefringent film is monitored, the birefringent film with high accuracy can be reproduced.

According to a second aspect of the present invention, the transmission substrate to be monitored is a substrate having a non-polarized total reflection film already formed on the back surface, and the retardation is obtained by vapor deposition in the vapor deposition device at the same time as the actual substrate. It is intended to monitor the birefringent film from the correlation of the above, and when the substrate to be vapor-deposited does not pass through or is moving during vapor deposition, etc., the substrate can be always installed and monitored at a position with a correlation, The vapor deposition can be terminated at the time when the birefringent film with the retardation is formed, and the birefringent film with high accuracy can be reproduced.

According to a third aspect of the present invention, in a device for manufacturing a birefringent film by obliquely vapor-depositing a metal oxide, linearly polarized light from a laser light source is vapor-deposited when the birefringent film is vapor-deposited. The transparent substrate is transmitted, the laser light is taken out from the introduction port on the opposite side, and the retardation of the substrate birefringent film during vapor deposition is directly monitored by using the Senarmont method. Since the vapor deposition can be stopped when the birefringent film of the retardation is formed, the retardation of the actual birefringent film is monitored even if there are other fluctuation factors during the vapor deposition. It has the effect that the refraction film can be reproduced.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3. (Embodiment 1) FIG. 1 is an embodiment of the present invention, in which a metal oxide such as Ta2O5 or TiO2 is transparent by oblique vapor deposition with an incident angle of 10 to 30 degrees by a vacuum vapor deposition apparatus, for example, an EB vapor deposition apparatus. It shows a manufacturing apparatus for directly monitoring the retardation of a formed birefringent film during the formation of the birefringent film on a substrate and ending vapor deposition at a desired retardation. Reference numeral 1 denotes a vacuum vapor deposition apparatus chamber, and 2 denotes a transparent substrate on which a birefringent film is formed. For example, an optically polished BK7 glass substrate is preferable. As an optical system for monitoring the retardation of the birefringent film, 3 is a laser light source, for example, a wavelength λ of 63
A 2.8 nm He-Ne laser or the like is used. When forming a 1/4 wavelength plate having a wavelength λ of an optical component, it is preferable to use a laser having a wavelength actually used. First, the optical system linearly polarizes the light output from the laser light source 3 with a polarizer 4 and linearly polarizes the laser light with the direction obliquely vapor-deposited from the vapor deposition source 6 on the transparent substrate 2 as the axial direction. Incident with the first direction inclined at an angle of 45 degrees from this axial direction. This laser light has 5 half mirrors and 1
Irradiate the transparent substrate 2 through the chamber introduction port 1. Further, the light passes through the transparent substrate 2 and is reflected vertically by the 12 non-polarization total reflection mirror to return the laser light to the original optical path, and again passes through the transparent substrate 2 and the introduction port of 11 to
And returns the laser light to the half mirror 5 to split the light. At this time, the laser light is polarized to be twice the retardation of the birefringent film formed on the second transparent substrate. Using the Senarmont method, the returned polarized laser light is fixed at a quarter wave plate with a wavelength λ of 7 at the same angle as the first direction linearly polarized by a polarizer of 4 and The laser light passing through the wave plate is passed through the rotatable polarization filter 8 and received by the photodetector 9 to convert the amount of light into a voltage. Here, regarding the fluctuation of the laser of 3 the voltage change of the laser light reflected by the half mirror of 5 is always measured by the photo detector of 10. In the present invention, for example, when the retardation of the target birefringent film is 90 degrees, the deflection filter rotation angle setting of 8 is set to 90 degrees. When the vapor deposition of the birefringent film progresses and the retardation approaches 90 degrees, the amount of light received by the photodetector 9 is extinguished and the output voltage decreases,
The minimum value is 90 degrees. By ending the vapor deposition at this time, the birefringent film having the desired retardation is precisely formed. The birefringent film having the desired retardation can be easily changed by matching the set angle of the polarizing filter of 8.

(Embodiment 2) FIG. 2 shows an apparatus for manufacturing a birefringent film when the substrate on which the birefringent film is formed is impermeable, and when the substrate itself moves during vapor deposition.
The transparent substrate and the non-polarization total reflection mirror of the above-mentioned embodiment are
The transparent substrate 2 having a non-polarization total reflection mirror film on the back surface is, for example, an optically polished BK7 substrate.
It is preferable to form a non-polarized total reflection mirror on the back surface of the glass substrate. As an optical system for monitoring the retardation of the birefringent film, 3 is a laser light source, for example, a He-Ne laser having a wavelength λ of 632.8 nm will be described. When doing so, the laser of the wavelength used is preferred. First, the optical system linearly polarizes the light output from the laser light source 3 by the polarizer 4 and linearly polarizes the laser light with the direction of oblique vapor deposition from the vapor deposition source 6 on the substrate 2 as the axial direction. The first direction is inclined at an angle of 45 degrees from this axial direction. This laser light passes through a half mirror 5 and a chamber introduction port 11 and a substrate 2 having a non-polarized total reflection mirror surface on the back side.
Incident perpendicularly. The incident laser light is reflected by the total reflection mirror on the back surface, passes through the birefringent film formed on the front surface of the substrate 2 twice, returns to the original optical path, passes through the introduction port 11 again, and passes through 5 It returns to the half mirror and the reflected laser light is reflected by the half mirror 5. At this time, the laser light is polarized twice as the retardation of the birefringent film formed on the second substrate. Using the Senarmont method, the 1/4 wavelength plate with the wavelength λ of 7 is fixed to the returned polarized laser light at the same angle as the direction of linearly polarized light with the polarizer of 4 and the quarter wavelength 8 laser light passing through the plate 7
The light is passed through the rotatable polarization filter of No. 1 and is received by the photodetector of No. 9, and the amount of light is converted into a voltage. Where 3
As for the fluctuation of the laser, the laser light reflected by the half mirror of 5 is constantly measured for the voltage change with the photo detector of 10. In the present invention, for example, when the retardation of the target birefringent film is 90 degrees, the polarization filter setting angle of 8 is set by adding 90 degrees and the offset angle. When the vapor deposition of the birefringent film progresses and the retardation approaches 90 degrees, the laser light amount of the photodetector 9 is extinguished, the output voltage decreases, and the polarization filter setting angle becomes the minimum value. At this time, the vapor deposition is ended to complete the formation of the target birefringent film. The offset angle can be added to the target retardation of the birefringent film to be manufactured when the retardation and the retardation of the monitor substrate deviate from each other, so that the target retardation can be accurately formed. it can.

(Embodiment 3) FIG. 3 shows an embodiment of the present invention, in which a metal oxide such as Ta2O5 or TiO2 is incident at an incident angle of 10 by a vacuum vapor deposition apparatus such as an EB vapor deposition apparatus.
Shows a manufacturing apparatus that directly monitors the retardation of the formed birefringent film while forming the birefringent film on the transparent substrate by oblique vapor deposition of 30 ° to 30 °, and finishes the vapor deposition at the target retardation. It is a thing. Reference numeral 1 denotes a vacuum vapor deposition apparatus chamber, and 2 is preferably a transparent substrate 2 on which a birefringent film is formed, for example, an optically polished BK7 glass substrate. As an optical system for monitoring the retardation of the birefringent film, 3 is a laser light source, for example, a wavelength λ
Will be described using a He-Ne laser having a wavelength of 632.8 nm. However, when forming a quarter-wave plate, a laser having a wavelength used is preferable. First, the optical system linearly polarizes the light output from the laser light source 3 by the polarizer 4 and linearly polarizes the laser light with the direction of oblique vapor deposition from the vapor deposition source 6 on the substrate 2 as the axial direction. The first direction is inclined at an angle of 45 degrees from this axial direction. This laser light is 1
The light enters the transparent substrate 2 through the first chamber introduction port. The incident laser light passes once through the birefringent film formed on the surface of the transparent substrate 2, is taken out of the chamber through the introduction port 13, and the transmitted laser light is
The retardation of the birefringent film formed on the second substrate is polarized. Using the Senarmont method, this polarized laser light is fixed at a quarter wave plate with a wavelength λ of 7 at the same angle as the direction of linearly polarized light with a polarizer of 4.
The laser light having passed through the / 4 wavelength plate 7 is passed through the rotatable polarization filter 8 and is received by the photodetector 9 to convert the amount of light into a voltage. Here, regarding the fluctuation of the laser of 3 the voltage change of the laser light reflected by the half mirror of 5 is always measured by the photo detector of 10. In the present invention, for example, when the retardation of the target birefringent film is 90 degrees, the polarization filter setting angle of 8 is set to 45 degrees, which is 1/2 of 90 degrees. When the evaporation of the birefringent film progresses and the retardation approaches 90 degrees, the laser light amount of the photodetector 9 is extinguished, the output voltage decreases, and the polarization filter setting angle becomes the minimum value at 45 degrees. By ending the vapor deposition at this time, the desired birefringent film can be formed and the birefringent film with the desired retardation can be manufactured with high accuracy. The setting angle of the polarizing filter is 1/2 of the target retardation of the birefringent film to be manufactured.

[0013]

As described above, according to the present invention, the birefringent film produced by oblique vapor deposition has a birefringence having an arbitrary retardation by arbitrarily setting the setting angle of the polarizing filter on the light receiving side. There is an advantageous effect that the film can be manufactured with high accuracy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an apparatus for manufacturing a birefringent film having a transparent substrate to be vapor-deposited according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an apparatus for manufacturing a birefringent film in which a total reflection mirror film is formed on the back surface of a vapor deposition substrate according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing an apparatus for manufacturing a birefringent film whose monitor is composed of a linear optical system according to a third embodiment of the present invention.

[Explanation of symbols]

 1 Vacuum Vapor Deposition Equipment Chamber 2 Transparent Substrate 3 Laser Light Source 4 Polarizer 5 Half Mirror 6 Vapor Deposition Source 7 1/4 Wave Plate 8 Polarizing Filter 9 Photodetector (Photodetector) 10 Photodetector (Photodetector) 11, 13 Vapor Deposition Device Introducing Port 12 No Polarized total reflection mirror

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01J 4/00 G01J 4/00

Claims (3)

[Claims] 1. An apparatus for manufacturing a birefringent film by obliquely vapor-depositing a metal oxide, wherein, during vapor deposition, linearly polarized light from a laser light source is transmitted through a vapor-deposited transparent substrate to form a total reflection mirror. With a half-mirror to reflect the returned light again through the transparent substrate, and use the Senarmont method to directly monitor the retardation of the substrate birefringent film during vapor deposition. An apparatus for manufacturing a birefringent film having. 2. The retardation of the birefringent film, wherein the transparent substrate to be monitored is a substrate on which a non-polarized total reflection mirror film has already been formed on the back surface, and is obliquely vapor-deposited in the vapor deposition device simultaneously with the actual substrate. The birefringent film manufacturing apparatus according to claim 1, wherein the birefringent film is indirectly monitored from the correlation. 3. An apparatus for manufacturing a birefringent film by obliquely vapor-depositing a metal oxide, wherein linearly polarized light from a laser light source is transmitted through a transparent substrate during vapor deposition of the birefringent film. An apparatus for producing a birefringent film, which has a vapor deposition stopping function of directly monitoring the retardation of a substrate birefringent film during vapor deposition by taking out a laser beam from an introduction port on the opposite side and utilizing the Senarmont method.