JPH06186563A - Alignment film manufacturing method, manufacturing apparatus and measuring apparatus - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a manufacturing method capable of easily manufacturing an alignment film for a liquid crystal device and a liquid crystal light valve, and further to provide a manufacturing apparatus and a substrate angle measuring apparatus used in the manufacturing method. To provide. [Configuration] A liquid crystal device comprising at least two substrates (11, 12) having electrodes (13a, 13b), an alignment film (17a, 17b), and a liquid crystal (18), and at least one substrate (11) After the electrode (13a) is vapor-deposited on the substrate, the substrate angle is continuously and simultaneously changed in the chamber, and the inorganic substance is obliquely vapor-deposited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an alignment film in a liquid crystal device or a liquid crystal light valve, a manufacturing apparatus and a measuring apparatus.

[0002]

2. Description of the Related Art The basic structure of a liquid crystal device comprises a substrate on which electrodes and an alignment film are formed, an opposing substrate on which electrodes and an alignment film are formed, and a liquid crystal layer between them. The liquid crystal device alignment method includes a horizontal alignment, a white alignment, represented by a twisted nematic (TN) mode and a super twisted nematic (STN) mode.
There are vertical alignments represented by the Lar guest-host (WT type GH) mode and inclined vertical alignments represented by the deformation of vertical aligned phases (DAP) mode.

FIG. 9 shows the structure of an optically writing liquid crystal light valve in a liquid crystal device. In the figure, on the substrate 11, an electrode 13a, a photoconductive layer 14, a light shielding layer 15, a dielectric mirror layer 16,
An alignment film 17a is formed. On the other hand, a counter electrode 13b and an alignment film 17b are formed on the counter substrate 12. Boards 11, 12
Are bonded together via a spacer, and the liquid crystal layer 18 is interposed between them.
Is provided. There are DAP mode and hybrid electric field effect mode (HFE) as a display mode of the optical writing liquid crystal light valve, and tilt vertical alignment and horizontal alignment treatments are used respectively.

In both modes, it is necessary to reduce the pretilt angle in order to suppress the reflectance when the voltage is not applied to the liquid crystal layer and increase the contrast. In order to satisfy this condition, a rubbing method is generally used in the horizontal alignment process. For example, polyimide is used as an alignment material by offset printing, firing is performed, and then rubbing and rubbing cleaning are performed to form an alignment film. As another horizontal orientation method, a two-step vapor deposition method (D.meyerhofer: Applied physics lett) in which the vapor deposition angle of SiO is changed from two directions is used.
er, 29 1976 p691). In the tilted vertical alignment treatment, a method of applying a vertical alignment agent to the above rubbing alignment film, a method of obliquely depositing SiO at two deposition angles and then applying a vertical alignment agent (Anna M.1 Lackner, J. David Margerum, Leroy J. . Mill
er, Willis H. Smith, Jr, SID 1990 P98), there is a rotary oblique evaporation method (JP-A-56-137330) for obliquely evaporating SiO by modulating the rotation speed of the substrate with a constant evaporation angle. .

[0005]

However, in the rubbing method, many steps must be performed from printing of polyimide to cleaning by rubbing. Further, rubbing may generate dust, static electricity may be generated, and the photoconductive layer, the light shielding layer, and the dielectric mirror may be peeled off due to friction in the optical writing liquid crystal light valve. On the other hand, the oblique deposition method has to be performed in a vacuum, and is not used for producing a simple matrix or a TFT liquid crystal panel at present because it is a laborious process. Further, the oblique vapor deposition for forming the alignment film is a process after the electrodes and the mirror are formed, but it is treated as a completely different process, and the formation of the electrodes and the mirror is not a process in vacuum. In practice, after forming the electrodes and mirrors, the substrate must be obliquely replaced for oblique vapor deposition, so the vacuum is returned to atmospheric pressure. Furthermore, in oblique vapor deposition, the alignment of liquid crystals is sensitive to the vapor deposition angle of the alignment film, and there is a problem in reproducibility.

It is an object of the present invention to provide a manufacturing method capable of easily manufacturing an alignment film for a liquid crystal device and a liquid crystal light valve, and further to provide a manufacturing apparatus and a substrate angle measuring apparatus used in the manufacturing method. To provide.

[0007]

A first manufacturing method is a liquid crystal device including two substrates having at least electrodes, an alignment film, and a liquid crystal, and the electrodes are vapor-deposited on at least one of the substrates and then continuously formed. At the same time, the substrate angle is changed in the chamber to obliquely vapor-deposit the inorganic material.

In the second manufacturing method, a photoconductive layer and a dielectric mirror layer are provided on one of the two substrates having electrodes, and an alignment film is provided on the dielectric mirror layer and the electrode of the other substrate, respectively. And a liquid crystal layer is disposed between the alignment films, a method of manufacturing an alignment film of a light-writing liquid crystal light valve,
It is characterized in that at least one of the substrate after the dielectric mirror vapor deposition and the substrate after the electrode vapor deposition is continuously and simultaneously changed in the substrate angle and the inorganic substance is obliquely vapor-deposited.

In the third manufacturing method, a photoconductive layer, a light-shielding layer, and a dielectric mirror layer are provided on one of the two substrates having electrodes, and the dielectric mirror layer and the electrode of the other substrate. In a method of manufacturing an alignment film of an optical writing liquid crystal light valve in which an alignment film is formed on each of the alignment films, and a liquid crystal layer is disposed between the alignment films, a substrate after vapor deposition of a dielectric mirror and a substrate after vapor deposition of an electrode. At least one of them is continuously and simultaneously changed in the substrate angle, and the inorganic material is obliquely vapor-deposited.

[0010]

In the first manufacturing method, the electrodes are vapor-deposited on at least one of the substrates, and then the substrate angle is continuously and simultaneously changed in the chamber to obliquely vapor-deposit the inorganic substance. In the second manufacturing method, the dielectric mirror is used. -At least one of the substrate after vapor deposition and the substrate after electrode vapor deposition is continuously and simultaneously subjected to oblique vapor deposition by changing the substrate angle. In the third manufacturing method, the substrate after dielectric mirror vapor deposition and electrode vapor deposition are used. Since at least one of the subsequent substrates is continuously and simultaneously changed in substrate angle and the inorganic substance is obliquely vapor-deposited, it is possible to significantly reduce the manufacturing process of the alignment film.
In particular, the effect is great in the manufacturing process of the alignment film in the optical writing light valve. In addition, the reproducibility of the alignment of the liquid crystal by oblique vapor deposition is improved by accurately monitoring and controlling the substrate angle. Further, since the rubbing method is not used, dust and static electricity are not generated, and in the optical writing light valve, the photoconductive layer, the light shielding layer, and the dielectric mirror are not peeled off by friction. Therefore, the manufacturing yield of the liquid crystal device is improved and the manufacturing cost can be significantly reduced.

[0011]

EXAMPLE An alignment method in which the display mode is the DAP mode in the optically writing liquid crystal light valve shown in FIG. 9 and a method of manufacturing a tilted vertical alignment film which is an example of the present invention will be described.

FIG. 7 shows a resistance heating vacuum vapor deposition apparatus for carrying out the manufacturing method. Put the sample in the crucible 55 and
By heating at 56, it is deposited on the substrate 54 on the rotary dome 52. The monitor 53 controls the membrane pressure.

A plurality of crucibles 55 and a plurality of heaters 56 are installed respectively, and a plurality of materials can be vapor-deposited by putting different samples in the respective crucibles 55. The substrate 54 is a rotary dome 52.
Since you can fix multiple on top, you can process many at once.

The light valve is manufactured by using an electrode, a photoconductive layer,
After cleaning the substrate with the light-shielding layer with pure water and IPA (isopropyl alcohol), the substrate holder on the rotating dome
Fixed to. The light shielding layer may not be formed if necessary. The degree of vacuum for vapor deposition is 2 x 10 ^-5 Torr.
The dielectric mirror was formed by alternately depositing about 30 layers of SiO ₂ (silicon dioxide) and TiO ₂ (titanium dioxide). In order to make the film distribution uniform, vapor deposition was performed while rotating the dome. FIG. 6 is a schematic diagram for explaining the formation of an alignment film after mirror vapor deposition. The angle of the substrate 54 can be changed by stopping the dome 52 after forming the mirror and operating the manipulator from outside the vacuum chamber 51.

The substrate angle was monitored using a laser light oscillator 57 and a photodetector array 58.

FIG. 8 is a diagram for explaining the principle of measuring the substrate angle. First, assuming that the incident light 82 is incident on the substrate surface 80 from the horizontal direction at θ, the reflection angle of the reflected light 83 is θ. Next, the incident light 82 is reflected by the substrate surface 81 rotated by δ to become reflected light 84 having a reflection angle θ−δ. Therefore,
The angle formed by the reflected lights 83 and 84 is 2δ, and the minute rotation angle of the substrate can be doubled.

The substrate angle can be accurately measured by receiving the reflected light by the photodetector array 86 and detecting the position. With this method, an accuracy of 0.2 ° can be obtained if the distance between the substrate 54 and the photodetector array 86 is 30 cm and the pitch of the photodetector array 86 is 2 mm. When changing the angle of another substrate, it is sufficient to rotate the dome to sequentially change the substrate angle, and the laser light oscillator 57 and the photodetector array 86 need only be one set.

Since the oblique deposition is performed with the dome closed, the crucible located directly below the center of the dome is considered in consideration of the symmetry with the substrate.
55 was used. The angle of the substrate for the oblique deposition can be selected as an appropriate value between 60 ° and 90 ° between the normal of the substrate and the crucible which is the deposition source. The material was SiO (silicon monoxide), and the dome was left stationary. First, it was obliquely vapor-deposited at 400 Å at 60 °. The film thickness can be appropriately selected from 50 to 500 angstrom.

Next, the angle of the substrate was changed to adjust the vapor deposition angle to 85 °, and flash oblique vapor deposition of about 10 Å was performed. As the vapor deposition material, SiO ₂ , MgF ₂ (magnesium fluoride) or CeO ₂ (cerium dioxide) can be used in addition to SiO ₂ .

Next, DMOAP, which is a vertical aligning agent on this substrate
(N, N-dimethyl-N-octadecyl-3-aminopropyltrimethoxysilyl chloride) was applied by a dipping method and baked at 130 ° C. for 20 minutes to form an alignment film.

On the other hand, on the counter substrate, SnO ₂ (tin dioxide) doped with Sb (antimony) was formed as a counter electrode by a sputtering method, and then DMOAP was applied by a dipping method without inclination treatment, and 130 ° C. It was baked for 20 minutes to prepare an alignment film. In the case of not performing the gradient treatment, a vapor phase reaction method, a spray method, or a coating method can be used as the counter electrode forming method. If necessary, the counter substrate may also be inclined. In that case, Sn doped with Sb on the counter substrate
After forming electrodes by resistance heating vacuum deposition of O ₂ , SiO 2 was deposited at 60 ° at 400 Å and then at 85 ° at 10 Å by oblique deposition in the same manner as in the case of the above substrate, followed by DMOAP.
The alignment film may be formed by coating and baking. A uniform alignment with a pretilt angle of 2 ° could be obtained by the alignment films on the substrate side and the counter substrate side.

In addition to DMOAP, FS150 (manufactured by Dainippon Ink), lecithin hexadecylamine, myristic acid complex and the like can be used as the vertical aligning agent.

FIG. 1 is a flow chart for explaining a substrate side manufacturing process of an embodiment of the present invention, and FIG. 12 is a conventional substrate side manufacturing process shown for comparison in order to better understand the present invention. Is a flowchart for explaining.

In FIG. 1, the oblique deposition (1-2) capable of accurately monitoring and controlling the substrate angle from the outside of the vacuum chamber.
As a result, the alignment became stable and good reproducibility was obtained, so after the dielectric mirror or electrode was formed (1-1), the alignment film could be formed in a vacuum as it is, and a troublesome cleaning process (Fig. 1
2, 12-2) could be omitted. Furthermore, P in FIG.
I printing (12-3), pre-baking (12-4), main baking (12-5), rubbing
Each process of (12-6) was able to reduce the man-hours to one process of oblique vapor deposition (Fig. 1, 1-2). This reduction in man-hours reduced the cost and improved the yield.

Since no dust or static electricity is generated by rubbing and the photoconductor layer, the light shielding layer, and the dielectric mirror are not peeled off by friction, the yield is improved also in this respect.

The counter substrate may be formed by only applying a vertical alignment agent on the electrodes, but when a tilting process is required due to the generation of domains, this embodiment has the above advantages. Further, even if it is not an optical writing liquid crystal light valve, it can be used for manufacturing an alignment film in a liquid crystal device having at least one substrate on which an alignment film is formed. Have. The display mode of the optically writing liquid crystal light valve shown in FIG.
A method of manufacturing a horizontal alignment film in which the mode is HFE mode, that is, a horizontal alignment film is described below.

FIG. 5 illustrates an embodiment of the present invention.
An EB (electronic beam) vapor deposition device is shown.

An electron beam 208 emitted from the electron gun 207
Is bent 180 ° by the magnetic field and hits the sample in crucible 205. The sample is heated and deposited on a substrate 204 fixed to a substrate rotating motor 209 which is connected to the rotating dome 202 through a tilt angle changing mechanism. The film thickness is controlled by the monitor 203. The crucible is on a rotating platform 206, and you can change the crucible by rotating the platform.
Multiple materials can be deposited by changing the sample in the crucible. Further, since a plurality of substrates can be fixed on the rotary dome, a large number of substrates can be processed at one time. To make a light valve, the substrate on which the electrodes, photoconductive layer, and light-shielding layer are formed is subjected to pure cleaning and IPA cleaning, and then fixed to the substrate holder on the rotating dome. The light shielding layer may not be formed if necessary. The degree of vacuum for vapor deposition is 2 x 10 ^-5 Torr. Dielectric mirror is Si
It was formed by alternately depositing about 20 layers of O ₂ and TiO ₂ . In order to make the film distribution uniform, the deposition can be further made uniform by rotating the dome.

FIG. 2 is a schematic diagram for explaining the formation of an alignment film after mirror vapor deposition. After forming the mirror, the dome 202 is stopped, and the manipulator is operated from outside the vacuum chamber 201 to change the slewing angle of the substrate rotation motor 209.
Change the angle of 4. The substrate angle monitor is a laser optical oscillator
This is performed by detecting the position of the reflected light on the substrate 210 by the photodetector array 211. When changing the angle of the other substrate, it is sufficient to rotate the dome to change the substrate angle sequentially, and the laser optical oscillator 210 and the photodetector array 211 need only be one set. Since the oblique deposition is performed with the dome stopped, the symmetry with the substrate is taken into consideration, and the deposition is performed using the crucible 205 located directly below the center of the dome. The vapor deposition angle is an angle between the normal line of the substrate and the hearth of the vapor deposition source, and an appropriate value between 60 ° and 90 ° can be selected. Here, it is set to 60 °.

The material is SiO 2 and the dome is kept stationary.
Angstrom was obliquely vapor-deposited. The film thickness is 50 to 20
You can select up to 00 angstrom. Subsequently, the vapor deposition angle is set to 80 °, and the vapor deposition direction is rotated by 90 ° by the substrate rotating motor 209 to perform flash oblique vapor deposition of SiO 2. The film thickness is about 1 to 3 Å. In addition to SiO
SiO ₂ , MgF ₂ and CeO ₂ can be used.

On the other hand, the counter substrate was doped with Sn (tin).
The counter electrode was formed by EB vapor deposition of In ₂ O ₃ (indium trioxide) (ITO).
The angle was 400 Å, and the vapor deposition direction was rotated by 90 °, and 2 Å SiO 2 was obliquely vapor deposited at a vapor deposition angle of 80 ° to form an alignment film. With the above alignment film, uniform alignment with a pretilt angle of 2 ° was obtained.

Using this device, the substrate rotation motor 209
It is possible to perform the rotational oblique deposition in which the pre-tilt angle is controlled by modulating the rotation speed of No. 1 to weight the deposition amount from each direction. By using this method, the tilted vertical alignment film of the above embodiment can be formed without using a vertical alignment agent, and the number of manufacturing steps can be reduced.

FIG. 3 is a flow chart showing an embodiment of a manufacturing process of a substrate for forming a dielectric mirror of the present invention, and FIG. 10 is a flow chart showing a manufacturing process of a substrate for forming a conventional dielectric mirror. -It is a chart. 4 is a flow chart showing an embodiment of the manufacturing process on the counter substrate side of the present invention, and FIG. 11 is a flow chart showing the conventional manufacturing process on the counter substrate side.

In FIG. 3 and FIG. 10, after the dielectric mirror vapor deposition (3-1), the orientation is controlled by oblique vapor deposition (3-2) which can accurately monitor and control the substrate angle from the outside of the vacuum chamber. Since the stable and good reproducibility can be obtained, the alignment film can be directly formed in a vacuum after the dielectric mirror or the electrode is formed, and the troublesome cleaning step (10-2) can be omitted.
Further, according to the embodiment, the processes of PI printing (10-3), pre-baking (10-4), main baking (10-5), and rubbing (10-6) can reduce the number of steps to one oblique evaporation process. did it.

In FIGS. 4 and 11, after deposition of the counter electrode (4
-1), the oblique evaporation (4-2) that can accurately monitor and control the substrate angle from the outside of the vacuum chamber has stabilized the orientation and has achieved good reproducibility. After the electrodes are formed, the alignment film can be formed in a vacuum as it is, and the troublesome cleaning step (11-2) can be omitted. Furthermore, according to the example, PI printing (11-3), pre-baking (11-4), main baking (1
The steps of 1-5) and rubbing (11-6) can reduce the number of steps to one step of oblique vapor deposition.

As described above, the reduction of man-hours reduces the cost and improves the yield. In addition, since dust and static electricity are not generated by rubbing and the photoconductor layer, the oblique layer, and the dielectric mirror are not peeled off by friction, the yield is improved also in this respect. This embodiment relates to the horizontal alignment, and the light writing liquid crystal light valve display mode includes HFE mode, GH (guest-host) mode, SSFLC (surface-stabilized ferroelectric liquid crystal) mode. Can be used. Further, it can be used for manufacturing an alignment film in a liquid crystal device having at least one substrate on which an alignment film is formed, even if it is not an optical writing liquid crystal light valve, and TN mode and STN are used as display modes. Mode, GH-STN
(Guest-host-super-twisted nematic) mode, GH-FLC (guest-host surface-stabilized ferroelectric liquid crystal) mode, DS (dynamic scattering) mode, DTN (depolarizer) -Shonin in a Twisted Nematic
Layer) mode, ECB (electrolytically controlled birefringence) mode, PC (
Layer transfer) mode, etc. It can also be used for HAN (Hybrid-Aligned Nematic Tech) mode in which one side is horizontally oriented and the other is vertically oriented.

[0037]

In the first manufacturing method, the electrodes are vapor-deposited on at least one of the substrates, and then the substrate angle is continuously and simultaneously changed in the chamber to obliquely vapor-deposit the inorganic substance. At least one of the substrate after the body mirror vapor deposition and the substrate after the electrode vapor deposition are continuously and simultaneously subjected to oblique vapor deposition of an inorganic material while changing the substrate angle. In the third manufacturing method, the substrate after the dielectric mirror vapor deposition is Since at least one of the substrates after the electrode deposition is continuously and simultaneously changed in the substrate angle and the inorganic substance is obliquely deposited, the manufacturing process of the alignment film can be significantly reduced.
In particular, the effect is great in the manufacturing process of the alignment film in the optical writing light valve. In addition, the accurate monitoring and control of the substrate angle improves the reproducibility of the alignment of the liquid crystal by oblique vapor deposition, and since no rubbing method is used, dust and static electricity are not generated. Therefore, the photoconductor layer, the light shielding layer, and the dielectric mirror are not peeled off. Therefore, the manufacturing yield of the liquid crystal device can be improved, and the manufacturing cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a manufacturing process on a substrate side according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining formation of an alignment film after mirror vapor deposition.

FIG. 3 is a flowchart showing an example of a manufacturing process of a substrate for forming a dielectric mirror of the present invention.

FIG. 4 is a flow chart showing an embodiment of a manufacturing process on the counter substrate side of the present invention.

FIG. 5 is a diagram showing an EB (electron beam) vapor deposition apparatus that is another embodiment of the present invention.

FIG. 6 is a schematic diagram for explaining formation of an alignment film after mirror vapor deposition.

FIG. 7 is a diagram showing a resistance heating vacuum vapor deposition apparatus for carrying out an example of a manufacturing method.

FIG. 8 is a diagram illustrating a principle of measuring a substrate angle.

FIG. 9 is a diagram illustrating an optically writing liquid crystal light valve.

FIG. 10 is a flowchart showing a manufacturing process of a conventional substrate for forming a dielectric mirror.

FIG. 11 is a flowchart showing a conventional manufacturing process on the counter substrate side.

FIG. 12 is a flowchart illustrating a conventional manufacturing process on the substrate side.

[Explanation of symbols]

 11, 12 Substrate 13a, 13b Electrode 14 Photoconductive layer 15 Light-shielding layer 16 Dielectric mirror layer 17a, 17b Alignment film 18 Liquid crystal 51, 201 Vacuum chamber-52, 202 Rotation dome 53, 203 Membrane pressure monitor 54, 204 Substrate 55, 205 Crucible 56 Heater 57, 210 Laser optical oscillator 58, 86, 211 Photodetector array 80, 81 Substrate surface 82 Incident light 83, 84 Reflected light 206 Crucible turntable 207 Electron gun 208 Electronic beam Mu 209 rotation motor

Claims (5)

[Claims] 1. Two substrates having at least electrodes,
In a liquid crystal device including an alignment film and a liquid crystal, an electrode is vapor-deposited on at least one substrate, and then an inorganic substance is obliquely vapor-deposited by continuously and simultaneously changing the substrate angle in a chamber. . 2. A photoconductive layer and a dielectric mirror layer are provided on one of two substrates having electrodes, and an alignment film is formed on each of the dielectric mirror layer and the electrode of the other substrate. In the method for manufacturing an alignment film for a light writing liquid crystal light valve in which a liquid crystal layer is disposed between the alignment films, at least one of the substrate after the dielectric mirror vapor deposition and the substrate after the electrode vapor deposition is continuously and simultaneously formed on the substrate. A method for manufacturing an alignment film, which comprises obliquely vapor-depositing an inorganic substance while changing an angle. 3. A photoconductive layer, a light-shielding layer, and a dielectric mirror layer are provided on one of two substrates having electrodes, and an alignment film is provided on the dielectric mirror layer and the electrode of the other substrate, respectively. Is formed, in the method for manufacturing an alignment film of an optical writing liquid crystal light valve in which a liquid crystal layer is arranged between the alignment films, at least one of the substrate after dielectric mirror vapor deposition and the substrate after electrode deposition, A method for producing an alignment film, which comprises successively and simultaneously changing the substrate angle and obliquely depositing an inorganic substance. 4. A manufacturing apparatus for use in the manufacturing method according to claim 1, further comprising means for accurately measuring the angle of the substrate. apparatus. 5. The measuring apparatus used in the manufacturing apparatus according to claim 4, further comprising a laser optical oscillator and a photodetector array, wherein incident laser light reflected by a substrate is incident. A measuring device characterized by accurately measuring the substrate angle at the position of the photodetector.