JPS60212221A - Photochemical reaction apparatus - Google Patents

Abstract

PURPOSE:To prevent ultraviolet rays from being interrupted in its transmission even in long-time operation, by providing a wiper mechanism for scanning the inner surface of the ultraviolet ray pervious window in a reaction vessel. CONSTITUTION:Photo-reactive gas is supplied into a reaction vessel 1 having an ultraviolet ray pervious window 14 by gas supply and exhaust systems 11, 12 and a substrate 4 being an article to be treated is irradiated by an ultraviolet ray source 3 from the outside of the reaction vessel 1 through the pervious window 14 and, further, the inner surface of the pervious window 14 is scanned by a wiper mechanism 5. Because the reaction product accumulated to the pervious window can be wiped off easily and perfectly by this simple structure, the transmission of ultraviolet rays is not interrupted even in long-time operation.

Description

[Detailed description of the invention] The present invention relates to a photochemical reaction device.

Recently, research has been conducted into methods for forming thin films of amorphous silicon used in photosensitive drums of electronic copying machines, solar cells, and the like. On the other hand, vapor deposition methods are also used to form insulating films and protective films for each woodcutter, and various vapor deposition methods have been proposed depending on the application, among which photochemical vapor deposition methods that utilize photochemical reactions are used to form films. It has the advantage of being extremely fast and being able to form a uniform coating even over a large area, and has recently attracted particular attention.

In conventional chemical vapor deposition or deposition methods that utilize photochemical reactions, a substrate is placed inside a reaction vessel that has a window that allows ultraviolet rays to pass through.
This method photochemically reacts the gas with an ultraviolet light source and deposits the reaction product on the substrate, and has the above-mentioned great advantages, but on the other hand, the reaction product also deposits or deposits on the transparent window of the container. It has been found that there is a drawback in that it greatly impedes the transmission of ultraviolet rays. For this reason, in the past, vapor deposition or deposition on the transmission window was suppressed by applying oil to the transmission window or flowing inert gas such as argon, but these measures had little effect and could last for a long time. During operation, the transmission of ultraviolet rays was gradually blocked.

SUMMARY OF THE INVENTION Therefore, the present invention provides a photochemical reaction device that has a simple groove structure, can completely remove deposits on the transmission window, and does not inhibit the transmission of ultraviolet light even when operated for a long time. The purpose is to provide a reaction vessel having a window for transmitting ultraviolet rays, a gas supply/exhaust mechanism for supplying the original reactive gas into the reaction vessel, and a substrate to be treated from outside the reaction vessel through the window. This is accomplished by a photochemical reaction device that includes an ultraviolet light source that illuminates the top and a wiper mechanism that scans the inner surface of the transmission window. If the blade part of this wiper mechanism is made of Teflon or non-woven fabric, or the surface is covered with these materials, the wiping effect will be improved. If a means is provided and it is possible to lower the temperature, the adhesion of deposits will be weakened and it can be easily wiped away by a wiper mechanism.

The present invention will be specifically described below based on embodiments shown in the drawings.

The reaction vessel 1 is provided with a photoreactive gas introduction hole 11 and an exhaust hole 12 connected to a pressure reducing device, and a substrate support 16 made of quartz glass is provided in the center of the ceiling. A UV transmitting window 14 made of quartz glass is provided on the lower surface, and this transmitting window 14Fi is hollow.
A water inlet 14a and a drain 14b are provided, through which cooling water passes. However, the transmission window 14 may be a single quartz glass plate without cooling means. A lamp body 2 is integrally installed below the transparent window 14, and a plurality of ultraviolet lamps 6, which are ultraviolet light sources, are arranged in parallel inside the lamp body 2 through a reflective member 21, and ultraviolet rays are emitted upward. irradiated. Here, the ultraviolet lamp 3 is an AC lighting low-pressure mercury lamp with a tube diameter of 18 mm, a lighting start voltage and pressure of 350 mm, a lighting voltage of 90 V, and a current of 5 A.
The device is not limited to this, and may be an electrodeless type radiation device or a plasma generator, as long as it generates a predetermined amount of ultraviolet rays. In addition, if necessary, the interior of the lamp body 2 may be configured to allow gas to flow through the gas supply/drainage mechanism.
It is possible to sit in a vacuum.

A temperature regulator (not shown) is attached to the substrate support 15, and the substrate 4 supported by this is an alumina plate having an outer diameter of 160 m and is heated to about 150°C. Note that by making the substrate support 15 rotatable, the ceiling surface of the reaction vessel 1 can be made movable, and a large number of substrates 4 can be efficiently processed by moving the substrates 4 in and out using the transport mechanism. A mixed gas consisting of argon as a carrier gas, mercury gas as a photosensitizer, and silicon tetrahydride as a decomposition vaporization gas is supplied from the introduction hole 11 into the reaction vessel 1. When using reactive gases, it is preferable to provide a plurality of introduction holes 11 to introduce each gas individually and mix them within the reaction vessel 1. It is preferable that a temperature regulator is provided in the introduction hole 11 to adjust the temperature of each dreg to an optimum temperature to promote the photochemical reaction.

Next, a wiper 5 is provided above the transmission window 14 and scans the inner surface of the transmission window 14. This wiper 5 is
The rotational force of the motor M is transmitted to the arm 51 via the link to perform a camera-type reciprocating motion, as shown in FIG.
The arm 51 has a main arm 51a and a sub-arm 51b assembled in a pantograph type, and has a large scanning area.

The blade 52 that contacts the inner surface of the transparent window 14 is made of a material with good adhesion and durability, such as Teflon or nonwoven fabric, and can wipe away fog on the transparent window 14 by scanning.

In the above apparatus, the pressure inside the reaction vessel 1 is reduced and the ultraviolet lamp 5 is turned on. Then, 5 watts of argon, 5 ton of mercury of silicon tetrahydride, and 5×10 m of mercury vapor are introduced through the introduction hole 11, but the ultraviolet rays pass through the transmission window 14 and reach the substrate 4 above. The silicon tetrahydride is photodecomposed and amorphous silicon is evaporated or deposited on the surface of the substrate 4 . At this time, a portion of the photoreactive gas descends and proceeds in the direction of the transmission window 14,
Here too, photolysis occurs and products begin to accumulate. However, when the accumulation occurs and it starts to become cloudy, the wiper 5 moves to the transmission window 14.
The fog is completely wiped away by the blade 52. In particular, since the transmission window 14 is cooled, even if the product is deposited, its adhesion is weak.Furthermore, applying oil to the transmission window 14 is even more effective in weakening the adhesion. , - times of scanning can be easily and completely wiped out. Incidentally, when photodecomposed under the above conditions, the deposition rate on the transmission window 14 is about 1 nm per minute, and the ultraviolet transmittance is 95% by about 1 nm of deposition.
%, but the permissible limit is about 95 inches.

Therefore, it is sufficient to scan the wiper 5 intermittently once every minute or a little more frequently.
The negative effect of blocking ultraviolet rays due to the scanning of the wiper 5 is very small and can be ignored.

As explained above, since the present invention is provided with a wiper mechanism that scans the inner surface of the transmission window, it is possible to easily and completely wipe away the products deposited on the transmission window. Accordingly, it is possible to provide a photochemical reaction device that has a simple structure and does not inhibit the transmission of ultraviolet light even when operated for a long time.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a wiper mechanism. 1... Reaction volume '6r 6... Ultraviolet lamp 4...
Substrate 14...Transparent window 5...Wiper 52...Blade Applicant USHIO INC. Agent Patent attorney Toranosuke Dehara Figure 1 Figure 2 Procedural amendment (voluntary) August 10, 1980 Commissioner of the Japan Patent Office Sen Shiga Manabu 1 Indication of the case 1982 Patent Application No. 67514 2 Title of the invention Photochemical reaction device 3 Relationship with the amended person case Special 8th Applicant Representative Oshiro Yumoto 4, Agent ” (8411) Patent Attorney 1) Shonosuke Hara 5 Date of amendment order 6 Number of inventions increased due to 4th amendment N/A 7 Column 8 for detailed explanation of the invention in the specification subject to amendment 8 Contents of amendment as attached On page 7, line 7 of the specification, next to "...is lit." add "However, the photochemical reaction may be caused under normal pressure without reducing the pressure inside the reaction vessel 1." . that's all

Claims (1)

[Scope of Claims] 1. A reaction vessel having a window for transmitting ultraviolet rays, a gas supply/exhaust mechanism for supplying a photoreactive gas into the reaction vessel, and a gas supply/discharge mechanism for supplying a photoreactive gas into the reaction vessel from outside the reaction vessel through the window for transmitting ultraviolet rays onto a substrate as an object to be processed. A photochemical reaction device that includes an ultraviolet light source that irradiates light, and a wiper mechanism that scans the inner surface of a transmission window. 2. The photochemical reaction device according to claim 1, wherein the blade portion of the wiper mechanism is made of Teflon, a nonwoven fabric, or a material coated with these. 2. The photochemical reaction device according to claim 1, wherein the transmission window is provided with a cooling means. 4. The photochemical reaction device according to claim 1, wherein the inner surface of the transmission window is coated with oil.