JPS6273623A - Photochemical reactor - Google Patents

Abstract

PURPOSE:To contrive the efficient utilization of the excitation light emitted from a lamp by providing an incident window functioning also as a lamp in a reaction vessel and arranging a reflective member on the outer surface of the incident window unitarily. CONSTITUTION:As an incident window 1a functions also as a lamp, only two planes, front and back sides of a structural member of the lamp become the surfaces giving a reflection loss before light enters a reaction vessel 7 and accordingly the reflection loss is reduced exceedingly. Also, a light reflecting film 2 is formed on a surface of the lamp on opposite side to the reaction vessel 7 by vapor deposition, so that the reflection of light to the side of the reaction vessel occurs inside the lamp due to the reflective film 2. Accordingly, there is no need of evacuation or inert gas purge of an optical path and the large spaces for them become unnecessary. For the light irradiation of a large- area substrate, a plane lamp is used with its extent made vertically. Consequently, an excitation light can be utilized efficiently.

Description

Detailed Description of the Invention [Industrial Application Field] This invention photochemically decomposes a reactive gas using lamp light, deposits a thin film on a substrate placed in the reactive gas, or deposits a thin film on a substrate placed in the reactive gas. This invention relates to a photochemical reaction device for etching.

[Conventional Technique 1] FIG. 2 is a cross-sectional side view showing an example of a conventional photochemical reaction device. In the figure, ■b is a lamp, 6 is a reflector, 7 is a reaction vessel, 5 is its entrance window, 3 is a substrate, 4 is a susceptor,
8 is a reaction gas, 9 is an exhaust gas, 10 is a reaction gas supply port,
1) is a gas outlet.

Next, the operation will be explained. The excitation light emitted from the lamp Ib passes through the entrance window 5 directly or after being reflected by the reflecting mirror 6.
and enters the reaction vessel 7. The incident excitation light photochemically decomposes the reaction gas 8 in the reaction container 7, and this decomposed gas causes the substrate 3 placed in the reaction gas 8 to
Deposit a thin film on or etch the thin film on the substrate 3.

[Problem that the invention seeks to solve]

Since the conventional photochemical reaction device is configured as described above, it has the following problems.

That is, first of all, before the excitation light emitted from the lamp reaches the substrate in the reaction vessel, there is always a reflection loss on the surface of the entrance window 5. This reflection loss R is given per surface, and in the case of a quartz window of Ω-1.50, which is a common transmitting material when using ultraviolet light as excitation light, the transmitted light is incident by passing through the window. Since the excitation light passes through the light and enters the reaction vessel, the amount of light falls to 100 x 0.922 = 84.9 (%).

In addition, in the device shown in Figure 2, there is always a gap between the window and the lamp, but in a light source like a lamp where the light emission is not a beam but spreads in all directions, the illuminance of the light is proportional to the square of the distance. This will result in a decline.

Furthermore, this device uses light in the vacuum violet range (with a wavelength of 2000 nm).
Ultraviolet light below Å: Important as excitation light for optical processes. ), the optical path must be evacuated or purged with a non-absorbing gas such as N2.

Furthermore, in order to effectively use the part of the emitted light that is emitted to the side opposite to the reaction vessel 7, it is necessary to use a reflecting mirror as shown in FIG. 6.

This invention was made in order to solve the problems mentioned in Section J2, and aims to provide a photochemical reaction device that can effectively utilize excitation light emitted from a lamp.

[Means for solving problems]

The photochemical reaction device according to the present invention has an entrance window that also serves as a lamp provided in a reaction container, and a reflective material is integrally provided on the outer surface of the entrance window.

[Effect]

In this invention, the entrance window of the reaction vessel also serves as a lamp, and the outer surface of the entrance window is integrated with a reflective material, so that the excitation light is directly and efficiently incident into the reaction vessel. .

〔Example〕

FIG. 1 is a cross-sectional side view of a photochemical reaction device according to an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 2 indicate the same parts, 1a is an entrance window provided in the reaction vessel 7 that also serves as a lamp, and 2 is a reflective material such as aluminum attached to the outer surface of the entrance window 1a by vapor deposition or the like. This is a reflective film that is integrated with the two.

Next, the effects will be explained. In this example, the entrance window 1
Since a also serves as a lamp, the only surfaces that cause reflection loss before light enters the reaction vessel 7 are the front and back surfaces of the lamp structure material, and the reflection loss is significantly reduced.

In addition, light reflection 1 is placed on the lamp surface on the opposite side of the reaction vessel 7.
j! 12 is formed by vapor deposition, etc., the reflection of light toward the reaction vessel side occurs within the lamp, and the above-mentioned evacuation of the optical path and purging with inert gas are no longer necessary. It also doesn't take up unnecessary space.

Note that in order to irradiate light onto a large substrate, a window area comparable to that of the substrate is required.For this reason, in the conventional device shown in FIG. If a planar lamp is used with the lamp extending in the direction perpendicular to the plane of the paper in FIG. 1, a large area of the substrate can be irradiated with light.

Furthermore, the present invention is applicable not only to film deposition and etching, but also to all devices that use other photochemical reactions.

〔Effect of the invention〕

As described above, according to the present invention, the entrance window also serves as a lamp, and a reflective material is integrally provided on the outer surface of the entrance window, so that excitation light for photochemical reactions can be absorbed without unnecessary reflection loss. This has the effect that it can be used effectively without occupying unnecessary space, and without having to vacuum the optical path or purge it with inert gas.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of a photochemical reaction device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional side view showing an example of a conventional photochemical reaction device. In the figure, 1a is an entrance window into which the lamp is directed, 2 is a reflective material, and 7 is a reaction vessel. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In a photochemical reaction device that uses a lamp as an excitation light source, the reaction vessel is provided with an entrance window that also serves as a lamp for inputting excitation light into the reaction vessel, and a reflective material is provided on the outer surface of the entrance window. A photochemical reaction device characterized by being provided in an integrated manner.