JPS60209248A - Photochemical reaction device - Google Patents

Abstract

PURPOSE:To prevent the deposition of the formed material on a transmissive window and to eliminate the hindrance to the transmission of ultraviolet rays by separating a gas supply and discharge mechanism and the transmissive window in a reaction vessel with an untraviolet transmissive porous plate, and providing an inert gas supply hole in the space between the porous plate and the transmissive window. CONSTITUTION:A photoreactive gas (e.g., SiH4) is supplied into a reaction vessel 1 having an ultraviolet transmissive window 14 through gas supply and discharge mechanisms 11 and 12, and ultraviolet rays are irradiated on a substrate 4 to be treated from an ultraviolet rays source 3 through the transmissive window 14 from the outside of the reaction vessel 1. In said photochemical reaction device, the gas supply and discharge mechanisms 11 and 12 and the transmissive window 14 in the reaction vessel 1 are separated with an ultraviolet transmissive porous plate 5, and a supply hole 10 of an inert gas (e.g., argon) is provided in the space between the porous plate 5 and the transmissive window 14. Consequently, the formed material is not deposited on the ultraviolet transmissive window 14, and the transmission of ultraviolet rays is not hindered.

Description

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

Recently, research has been carried out on methods of forming vapor deposited amorphous silicon films 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 various insulating films and protective films, and various vapor deposition methods have been proposed depending on the application. The deposition method has the advantage of being extremely fast in forming a film and being able to form a uniform film 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 light 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 on the transparent window of the container, causing the ultraviolet rays to evaporate. It was found that there are drawbacks that greatly impede the permeation of

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 an inert gas such as argon.

However, although applying oil makes it easier to remove the accumulated reaction products, it is less effective in preventing the accumulation, and the inert gas nozzle is placed so that the ultraviolet rays are not blocked, allowing them to pass through. It is difficult to uniformly spray the windows, and these measures have not been effective enough.

Therefore, an object of the present invention is to provide a photochemical reaction device that has a simple structure and does not allow products to accumulate on the ultraviolet light transmitting window and prevent the transmission of ultraviolet light from being inhibited. A photochemical reaction that includes a reaction container having a transmission window, a gas supply/exhaust mechanism that supplies a photoreactive gas into the reaction container, and an ultraviolet light source that irradiates the substrate, which is the object to be processed, from outside the reaction container through the transmission window. The apparatus is characterized in that a gas supply/exhaust mechanism in a reaction vessel and a transmission window are partitioned by an ultraviolet-transparent perforated plate, and an inert gas supply hole is provided in the space between the perforated plate and the transmission window. That is.

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 quartz glass substrate support 13 is arranged in the center of the interior so as to be movable up and down. . The top surface is provided with an ultraviolet light transmitting window 14 made of quartz glass, and a lamp body 2 is integrally connected to the top of the window 14, and an ultraviolet light source, which is an ultraviolet light source, is connected to the ceiling of the window 14 through a reflective member 21. A plurality of /pu 5 are arranged in parallel. Here, the ultraviolet lamp 5 has a tube diameter of 18 m and a lighting start voltage of 55 m.
The lamp is a low-pressure mercury lamp with an alternating current of 0 V, a lighting voltage of 90 V, and a current of 5 A. However, it is not limited to this, and may be an electrodeless lamp device or a plasma generator. It is sufficient as long as it generates. Further, a mechanism that allows gas to flow into the space within the lamp body 2 may be provided as necessary.

A temperature controller as shown in the diagram is attached to the substrate support stand 15, and the substrate 4 supported by this is an alumina plate having an outer diameter of 160s+ and is heated to about 150°C. In addition,
This substrate support stand 15 can be made rotatable in a turn-chip or pull-like manner, or can be made movable within the reaction vessel 1, so that a large number of substrates 4 can be efficiently processed by loading and unloading the substrates 4 with a 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 to mix them within the reaction vessel 1. It is preferable that a temperature controller is provided in the introduction hole 11 to adjust each gas to an optimum temperature to promote the photochemical reaction.

Next, a perforated plate 5 is disposed above the introduction hole 11 and the exhaust hole 12 and near the transmission window 14 to cover the transmission window 14, thereby partitioning the inside of the reaction vessel 1. This perforated plate 5 is made of quartz glass that transmits ultraviolet rays, and is provided with a large number of ejection holes 51 having a diameter of 0.2 cm in a 1 inch pitch.

This porous plate 5 is made of, for example, MgF2 + CaF2 +L
A crystal plate such as tF may be used, and the ejection holes 51 may be in the form of slits, as long as they are made of a material that transmits ultraviolet rays and can eject gas uniformly from its surface. Then, an inert gas supply hole 1o such as argon is provided above the perforated plate 5, and the inert gas is supplied from this into the space between the transmission window 14 and the perforated plate 5, and the inert gas is supplied from the nozzle hole 51 downward. It's getting so hot that it seems like it's going to erupt.

In the above apparatus, the pressure inside the container 1 is reduced and the ultraviolet lamp 3 is turned on. However, the photochemical reaction may be caused under normal pressure without reducing the pressure inside the reaction vessel 1. Then, 5wHg of argon, 3-Hg of silicon tetrahydride, and 3X10-5smHg of mercury vapor are introduced through the introduction hole 11, and at the same time, 100mHH of argon is supplied through the supply hole 1o, but ultraviolet rays are transmitted through the transmission window 10. The light passes through the porous plate 5 and is irradiated onto the substrate 4, whereby silicon tetrahydride is photodecomposed and amorphous silicon is vapor-deposited or deposited on the substrate 4. At this time, a portion of the photoreactive gas rises and moves toward the transmission window 14, but inert gas is ejected from the perforated plate 5 disposed in the middle as shown by the arrow in FIG. It is gushing out from hole 51.

Therefore, the photoreactive gas passes through the ejection hole 51 and passes through the transmission window 14.
Therefore, no reaction products are deposited on the transmission window 14. Furthermore, the inert gas ejected from the ejection hole 51 into the space on the side of the base @4 whose pressure has been reduced is diffused from side to side at the same time as the ejection, and flows to the lower surface of the perforated plate 5, so that no reaction products are present on the perforated plate 5 as well. Does not accumulate. In this way, since amorphous silicon is not deposited on both the transmission window 14 and the porous plate 50, there is no clouding even during long-time operation, and the transmission of ultraviolet rays is not inhibited.

As explained above, the present invention provides partitioning between the gas supply and exhaust mechanism in the reaction vessel and the transmission window with an ultraviolet-transparent perforated plate,
An inert gas supply hole was provided in the space between the perforated plate and the transparent window, and the inert gas was ejected from the ejection hole of the perforated plate, so that the ultraviolet rays were not blocked by the nozzle and were applied to the surface of the perforated plate. Inert gas flows uniformly and product does not accumulate.

Therefore, according to the present invention, it is possible to provide a photochemical reaction device that has a simple structure, in which no products are deposited on the ultraviolet light transmission window, and in which the transmission of ultraviolet light is not inhibited.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a perspective view of a perforated plate, and FIG. 5 is an explanatory diagram of an inert gas jetting situation. DESCRIPTION OF SYMBOLS 1... Reaction container 2... Lamp body 3... Ultraviolet lamp 4... Substrate 5... Porous plate 10... Inert gas supply hole 11... Introduction hole 12.
...Exhaust hole 13...Substrate support stand 14...Transmission window
51...Blowhole applicant Ushio Inc. agent Patent attorney Toranosuke Tahara Figure 1, 13 Figure 3 Procedural amendment (voluntary) August 10, 1980 Commissioner of the Japan Patent Office Manabu Shiga 1, Indication of the case 1980 Patent No. 1 No. 63413 2, Title of the invention: Photochemical reaction device 3, Relationship with the case of the person making the amendment: Patent applicant representative: Okura Yumoto 4, attorney: 6, Number of inventions increased by amendment: No specification No. On page 4, line 17, ``A mechanism that allows gas to flow into the space may be provided.'' is corrected to ``A mechanism that allows gas to flow into the space or to reduce the pressure of the space may be provided.''that's all

Claims (1)

[Claims] It includes a reaction vessel having an ultraviolet ray transmission window, a gas supply/exhaust mechanism that supplies a photoreactive gas into the reaction vessel, and an ultraviolet light source that irradiates the substrate, which is the object to be processed, from outside the reaction vessel through the transmission window. A photochemical reaction device in which a gas supply/exhaust mechanism in a reaction vessel and a transmission window are partitioned by an ultraviolet-transparent perforated plate, and an inert gas supply hole is provided in the space between the perforated plate and the transmission window. A photochemical reaction device featuring: