JPH03164712A - Liquid crystal diaplay device and its production - Google Patents

Abstract

PURPOSE:To uniformize the thickness of a film in a substrate and to improve defect problems by orienting an Si-Cx-Oy film formed by oblique vapor deposition while controlling x and y to 0.02 < x < 0.4 and 1 <= y < 2. CONSTITUTION:A reaction vessel 4 having an open window 4a on the transparent insulating substrate 6 side is set at the lower part in a vacuum device 2, a vaporization source and a gas injection port 21 for injecting a gas consisting essentially of oxygen into the vessel 4 are provided in the vessel 4, Si and C are packed in the vaporization source, the Si and C are heated and vaporized, and Si is allowed to react with C at 0.02 < x < 0.4 and 1 <= y < 2 to form Si-Cx-Oy. The vapor of the Si-Cx-Oy is discharged from the window 4 in the vessel 4, and exposed on the surface of the substrate 6 inclined at an incident angle different from that of the vapor of Si-Cx-Oy by angle other than 0 deg. to form an Si-Cx-Oy film. The oriented film thus formed is applied to a liq. crystal display device, and the defect problem and the problem related to the mechanical adhesion are improved.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention (Table 1) relates to a liquid crystal display device using a liquid crystal alignment film laminated by oblique vapor deposition on the surface of a transparent insulating substrate for a liquid crystal display element, and a method for manufacturing the same. There are several conventional liquid crystal alignment processing methods, and among them, oblique evaporation is known as an oblique alignment processing.

This oblique evaporation method is the only method that can set the tilt angle of the liquid crystal molecules.SiO is selected as the material to be evaporated, and the vapor flow of the evaporation material is introduced onto the substrate surface from an oblique angle. In the oblique evaporation method, when the incident angle θ is increased (it is generally known that θ>70 degrees), an inclined column is formed, and the long axis of the liquid crystal molecules is aligned in the direction of the column. Accordingly, liquid crystal molecules are oriented obliquely at a certain inclination angle4.As a method for obtaining the SiO vapor flow, SiO is filled into an evaporation source such as a quartz crucible or tantalum crucible, and an appropriate heating means is used to generate the SiO vapor. LSiO was selected as the material to be evaporated, and this SiO
Attempts to obtain a vapor flow of SiO using an appropriate heating means have resulted in the following problems:
Since O is in the form of powder or lumps, and SiO exhibits sublimation properties, the Si
There were cases where O bumping occurred, and SiO as a substance to be evaporated was scattered into the vacuum equipment, and some of it directly hit the substrate.Furthermore, the thin film deposited on the substrate was SiO.
z (however, L1≦2≦2), and the number of oxygen atoms is undefined. It was not possible to obtain a tilted alignment film with good properties due to the weak adhesion strength of the tilted alignment SiO+ film to the substrate by the conventional method. - This is an alignment film with a part of the film destroyed. When attempting to process the tilted alignment layer on multiple substrates or large-area substrates, the above-mentioned problems occur more conspicuously than in the conventional method. In view of the above-mentioned circumstances, the present invention has been developed in view of the above-mentioned circumstances, where the productivity, practicality, and reliability of the method were poor.In the oblique alignment treatment using the oblique evaporation method, it is possible to control the uniform film thickness within the substrate and significantly reduce the problem of defects. A liquid crystal display device using a liquid crystal alignment film, which improves productivity and practicality by forming a tilted alignment layer with improved reproducibility, and improves reliability by strengthening adhesive strength to a substrate, and a method for manufacturing the same. The purpose is to provide.

Means for Solving the Problems In order to achieve the above objects, in the present invention, X and y are set to 0.
The alignment film is a Si-Cx-Oy film formed by oblique deposition with 02<x<0.4 and l≦y<2. As a manufacturing method for this alignment film, a reaction tank having at least an opening window on the side of the transparent insulating substrate is placed in the lower part of a vacuum device, and an evaporation source and a gas mainly composed of oxygen are ejected into the reaction tank. The evaporation source is filled with Si and C, and the Si and C are heated and evaporated. The Si and C are reacted with oxygen in the reaction tank, and 0.02<x< 0
．． 4. Si-Cx-Oy is generated with l≦y such that 2, and a vapor flow of Si-Cx-Oy is released from an open window in the reaction tank, and the vapor flow of Si-Cx-Oy is different from 0 degrees. A manufacturing method is used in which a Si-Cx-Oy vapor flow is exposed to the surface of a transparent insulating substrate tilted at different incident angles to form a Si-CXOy film.

Effect As mentioned above, X and y are 0.02<x<0.4, l≦y
≦2, the Si-Cx-Oy film ζ formed by oblique evaporation of reaction products in an oxygen atmosphere has an appropriate degree of oxidation and separation, and has an active surface texture. In a liquid crystal display device to which this method is applied, problems related to defects and mechanical adhesion are improved. Moreover, the Si element and C element filled in the evaporation source can be dissolved continuously and stably, and by controlling the amount of heating energy applied to Si and C and the flow rate of gas in the reaction tank, 0.02<x <0,4. S where 1≦y<2
i -Cx-Oy is produced, and a vapor flow of the Si-Cx-○y is released from an open window in the reaction vessel, and the Si-Cx-Oy is produced.
The Si-Cx-Oy vapor flow is exposed to the surface of a transparent insulating substrate that is tilted at an angle of incidence different from 0 degrees and transported at a controlled speed.
Since this is a manufacturing method that forms an Oy film, it is possible to control a uniform film thickness, and moreover, it is possible to obtain an alignment film with reproducibility.

EXAMPLE Hereinafter, a liquid crystal display device and a method for manufacturing the same according to an example of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing an outline of the manufacturing apparatus used in this example, and FIG. 2 is an enlarged perspective view of a part of FIG. 1.

A vacuum device 2 equipped with a high vacuum pump 1 is provided. Although the reaction tank 4 is provided, the reaction tank 4 is provided with an evaporation source 3 and a gas introduction system 21 provided with a gas outlet for ejecting gas containing oxygen as a main component.

A gas introduction system 21 (a cylinder 21V placed in the atmosphere and filled with a gas mainly composed of oxygen and the vacuum device 2)
an external vibe system 21a connected to the vacuum device 2;
is connected to the external pipe system 21a inside and extended to the vicinity of the evaporation source 3 in the reaction tank 4, and the tip thereof is connected to the external pipe system 21a and is connected to the external pipe system 21a.
It is composed of an internal pipe system 21c provided with an opening for ejecting the gas as shown in 1b. 21dl friend in the same picture
This is a valve that adjusts the flow rate of the gas flowing into the vibe system 21.

The evaporation source 3 is filled with Si element and C element 3a, and the vapor flow of Si and C is performed by heating means consisting of an electron beam or laser that can continuously control the heating energy applied to the SL and C element 3a. It is desirable to obtain - Arrow 3b shows the trajectory of electrons in a deflection type electron beam evaporation source.

By controlling the amount of heating energy applied to Si and C and the flow rate of gas, it is generated by the reaction between the vapor flow of Si and C and oxygen gas in the reaction tank 4.0゜02<x<0
．． 4. Si-Cx-Oy is generated with 1≦y
A vapor stream of
It is used to interrupt the flow of Si-Cx-Oy vapor released from a at any time.

When the shutter 5 is open, the Si-
Transparent insulating substrate 6 tilted at an incident angle θ different from 0 degrees (generally known to be θ>70 degrees) with respect to the vapor flow of Cx-Oy 6 The upper part of the cough shutter 5 The Si-Cx-Oy is disposed on the surface of the transparent insulating substrate 6.
A Si-Cx-Oy gradient orientation layer is formed by exposure to a vapor flow of .

Although not described in detail in the figure, in this embodiment (Table 1), even if a means for moving the transparent insulating substrate 6 continuously or intermittently is provided, the transparent insulating substrate 6 located at the substrate supply location 6a is moved to a predetermined position. While the substrate is tilted at a predetermined angle at a speed and moved to the substrate storage location 6b (although the arrow 6d indicates an example of the moving direction), it is exposed to the vapor flow of the Si-Cx-Oy. This is an exposure limiting window used to limit the location where the insulating substrate 6 is exposed to the Si-Cx-Oy vapor flow.A diaphragm window 5b is provided between the exposure limiting window 6c and the shutter 5. It is used to limit the flow of Si-Cx-Oy vapor that is disposed and discharged from the open window 4a of the reaction tank 4 and enters the transparent insulating substrate 6.

20 in the figure is a holding plate, which includes the evaporation source 3 and the reaction tank 4.
, the shutter 5, the aperture window 5'o, the transparent insulating substrate 6, etc., within the vacuum apparatus 2. The Si and C elements filled in the evaporation source 3 are used to measure the degree of vacuum.
It is possible to form a compound such as -Cx and treat the reaction product of the compound and oxygen gas as a tilted alignment layer. In addition, by configuring a plurality of evaporation sources, filling each evaporation source with Si and C, and individually controlling the amount of heating energy applied to Si and C, Si and C vapor can be generated in the reaction tank 4. It can be produced by the reaction between oxygen gas and oxygen gas.

FIG. 3 shows an example of data regarding the occurrence of defects in a liquid crystal display device in which a Si-Cx-Oy tilted alignment film formed by the above method is formed on the surface of a transparent insulating substrate. This is an example where y=t, s, and even though the horizontal axis shows the amount of C and the vertical axis shows the defect incidence rate R, the defect incidence rate R used here is The area ratio α of the part containing defects is first normalized by the light value α(0) when the desired Ax=O.The defect occurrence rate R decreases with the addition of C.Wl x=0.02 The defect occurrence rate R becomes approximately 0.5 near x.
= ,0,1-0.

In the range of 3, it shows a constant value of 0.1. After that, the defect occurrence rate R gradually increased as the amount of C increased, and x=0.
Around 4, the defect incidence rate R (Y) increases rapidly after reaching approximately 0.5.Almost the same trend as above can be observed for other y values in the range of 1≦y≦2; As of now, the role of C has not been clearly clarified experimentally (~U), but the following speculation is possible7. The bond in Si-0 is a strong ionic bond (~
Moreover, as mentioned above, the Si-0 thin film formed by reactive vapor deposition in an oxygen gas atmosphere is active. On the surface, it interacts strongly with liquid crystal molecules. On the other hand, Si
Since the -C bond is a strong covalent bond, it is expected to have the effect of relaxing the interaction with the liquid crystal molecules described above. However, as the number of Si-C bonds in the film increases, the effect of Si-0 bonds becomes weaker, and therefore, on the surface of the inclined column of the Si-Cx-Oy thin film constructed by the above method, If y and y are selected, a surface with appropriate ionic and covalent bonding properties will be formed. It is expected that such microscopic behavior is related to the above-mentioned defects even if a moderate interaction occurs.

In the above explanation, a transparent insulating substrate is used as an example of a substrate to be oriented at an angle, but a flexible transparent insulating substrate such as plastic can also be used to fully utilize the gist of the present invention. Since it is configured as shown above, it produces the effects described below.
．． Si-Cx- formed by oblique evaporation of the reaction product in an oxygen atmosphere with 02<x<0.4 and l≦y≦2.
Since the Oy film ζ has an appropriate degree of oxidation, polarization, and active surface properties, defects and mechanical adhesion problems can be improved in liquid crystal display devices to which this alignment film is applied.

Moreover, the SL element and C element filled in the evaporation source must be dissolved stably for a long time, and the Si
and 0.02<x<0.4 by controlling the magnitude of heating energy applied to C and the flow rate of gas. 1≦y
2, a vapor flow of the Si-Cx-Oy is released from an open window in the reaction tank, and an incident angle different from 0 degrees from the vapor flow of the Si-Cx-Oy is generated. S
Since this is a manufacturing method that forms an i-Cx-Oy film, it is possible to control the uniform film thicknessa.The film-forming conditions applied to the above manufacturing method are also fully controllable, making it possible to improve reproducibility. A certain alignment film can be obtained. Therefore, the present invention provides a liquid crystal display device and its manufacturing method that improves the productivity and practicality of processing the tilted alignment layer on a plurality of substrates or large area substrates, and improves the reliability of the tilted alignment layer. It can be said.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) In a liquid crystal display device including a transparent insulating substrate including a pair of electrode parts, an alignment film formed on the surface of the transparent insulating substrate, and a liquid crystal sandwiched between the transparent insulating substrates, Si-
A liquid crystal display device characterized in that a Cx-Oy film is used as an alignment film. (2) A reaction tank having at least an opening window on the side of the transparent insulating substrate including the electrode part is arranged in the lower part of the vacuum apparatus, and an evaporation source and a gas mainly composed of oxygen are spouted into the reaction tank. Install a spout, fill the evaporation source with Si and C, heat and evaporate it, and react the Si and C with oxygen in the reaction tank to produce 0.02<x<0.4, 1≦y≦ S as 2
i-Cx-Oy is produced, and a vapor flow of Si-Cx-Oy is released from an open window in the reaction vessel to produce Si-Cx-Oy.
A Si-Cx-Oy vapor flow is exposed to the surface of a transparent insulating substrate tilted at an incident angle different from 0 degrees to the y vapor flow to form a Si-Cx-Oy film, thereby forming a liquid crystal alignment film. A method for manufacturing a liquid crystal display device characterized by: