JPS62196818A - Vapor deposition device - Google Patents

Abstract

PURPOSE:To prevent the cloudiness of an observation port by the gettering action of a deposition layer on an adsorption wall in the vicinity of the observation port by attaching vapor from an evaporation source for gettering onto the adsorption wall. CONSTITUTION:Vapor is not projected directly to main evaporation sources 2a, 2b, a substrate 3, a heater 4, an observation port 5, etc. from an evaporation source 7 for gettering, and the evaporation source 7 discharges its own vapor near a space in which there is a vapor flow toward the observation port 5 from the main vapor sources 2a, 2b. A masking shield 8 limiting the direction of discharge of the vapor of the evaporation source 7 for gettering and an adsorption wall 9, on which the vapor of the evaporation source 7 is deposited and which adsorbs other vapor, are mounted onto the inner wall of a tank 1. Consequently, the single crystal of gallium arsenide is grown on the substrate 1, and the inside of the tank 1 during deposition can be observed from the observation port 5. The gallium vapor of the evaporation source 7 for gettering adheres on the adsorption wall 9 in the vicinity of the observation port 5, arsenic vapor projected to the adsorption wall 9 section is coupled, the reevaporation of the arsenic vapor is prevented, one part of the gallium vapor of the evaporation source 7 is combined with arsenic in a space, and arsenic is changed into vapor difficult to be reevaporated and attached onto the inner wall of the tank 1 up to the observation port 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a vapor deposition layer in which an observation window is prevented from accumulating vapor.

[Conventional technology]

Fig. 2 is a cross-sectional view showing a conventional vapor deposition apparatus, which is a molecular beam epitaxy apparatus;
Vacuum chambers (2a), (2b) that can be inspected using an internal inspection port, etc. that makes the interior vacuum or atmospheric pressure.
) are all main evaporation sources, and here the former is a gallium evaporation source, the latter is an arsenic evaporation source, and (3) is the gallium vapor and arsenic vapor from the gallium evaporation source (2a) and the arsenic evaporation source (2b). (4) is a heater that heats the substrate (3) to improve the crystallinity of the gallium arsenide deposited layer; (5) is a vacuum chamber (1); An observation window is attached to the gallium evaporation source (2a), the arsenic evaporation source (2a), the substrate (3), the heater (4), etc. from outside the vacuum chamber (1).

(6) is a shell that is closed to prevent gallium vapor, especially arsenic-A vapor, from adhering to the observation window (5) when not observing, and is open when observing.

Since the conventional vapor deposition apparatus was constructed as described above, the ratio of the number of gallium and arsenic atoms incident on the substrate (3) is optimized to 1, for example, gallium with an atomic ratio of 1=1. The arsenic single crystal /a is being grown, and the observation window (53) is being used to observe whether there are any abnormalities occurring inside the growing process.

[The problem that the invention attempts to solve]

In the conventional vapor deposition apparatus as described above, arsenic vapor from the main evaporation source (2b) is passed through the observation window (5) as described below.
If arsenic deposits were deposited, it became impossible to observe the inside of the tank (1), and there was a problem in that it was necessary to frequently reduce the pressure inside the tank (1) to atmospheric pressure to remove the deposits of arsenic.

In other words, even if arsenic vapor adheres to the surface of a structure in the tank (1), it easily separates and reevaporates easily. Even if it is not in the position of 7 yanta (6), the repeated re-evaporation will reach the observation window (5) and cloud it.

This invention has been developed to solve the above-mentioned problems.
Even if steam is generated that fogs the window (5)
It is an object of the present invention to provide a vapor deposition device that can reduce the number of times the above-mentioned removal work is performed by preventing the vapor from adhering to the surface.

[Means for solving problems]

In the vapor deposition apparatus according to the present invention, the main evaporation source is S from the atmosphere.
1 on the substrate placed in the tank and placed in the tank.
This vapor is released to form a vapor deposit layer, and an observation window is provided on the wall of the tank to enable observation of the inside of the tank, and to detect whether the vapor is emitted from the gettering evaporation source or the main evaporation source. Of these, vapors that are difficult to re-evaporate not only themselves but also the reactants are difficult to re-evaporate, compared to vapors that are easy to re-evaporate. The light is emitted toward the substrate, avoiding the substrate, the main evaporation source, and the observation window.

[Effect]

In this invention, vapor from the gettering evaporation source adheres to the adsorption wall near the observation window, and mainly enters the wall surface from the main evaporation source due to the gettering action of this deposited layer. Reduces steam re-evaporation and prevents fogging of the observation window.

〔Example〕

FIG. 1 is a sectional view showing one embodiment of the present invention, and C1
) or 6) are the same or equivalent parts as the conventional one, and (1) is the main evaporation source (2a), (zb), substrate (3), heater (4), observation window (5), etc. Steam does not directly enter the observation window (
5) A gettering evaporation source that emits its own vapor in the vicinity of the space where vapor flows from the four sides exist, and in this embodiment, another gallium evaporation source, (8) is a gettering evaporation source (7). ), a shielding plate (9
) is an absorption wall that deposits the vapor of the evaporation source (1) and adsorbs other vapors, and 6 is a part of the inner wall of the tank +1) in this embodiment.

Since this embodiment has the above-mentioned configuration, the substrate is the same as the conventional one. (11
This includes growing single crystals of gallium arsenide.

Needless to say, the inside of the tank (1) during deposition can be observed through the observation window (5).

By the way, the gallium vapor from the gettering vapor source (7) adheres to the adsorption wall (9) near the observation window (5) and combines with the arsenic vapor that enters this area, causing this vapor to reevaporate. A part of the tank (1
) We are trying to solve the above problem by making it adhere to the inner wall.

In addition, in the above embodiment, gallium arsenide was deposited on the substrate (3).
Although we have described the case of epitaxial growth, it is not necessary to grow a single crystal, so the substrate does not need to be a single crystal of gallium arsenide, gallium aluminum arsenide, or kermanium, and instead of gallium arsenide, Even when growing gallium aluminum arsenic, arsenic alone is a cause for concern, and when it is grown into a film, the vapor emitted from them is the most likely to re-evaporate among the main evaporation sources. Re-evaporation source 7) Materials in which the vapor emitted from the re-evaporation source 7) and the vapor in combination with the former are difficult to re-evaporate may be selected for each evaporation source.

In addition, in the above embodiment, the case where molecular beam epitaxial growth is achieved was described, but this example can also be applied to general vacuum evaporation in which the deposition rate of potassium atoms and arsenic atoms is not precisely controlled. , it goes without saying that this can also be applied in the case of sputtering.

Also, in the above example, gallium and arsenic were evaporated from a gallium evaporation source (2a) and an arsenic evaporation source (2b), respectively, or a mixture or compound of both may be evaporated from a single evaporation source. Needless to say.

In addition, in the above embodiment, the suction wall (9) was rarely used as a part of the inner wall of the tank (1), but if a special structure is installed at 1iZm nearer than the window 15) Ic that does not obstruct observation, and that wall surface is utilized. more effective.

〔Effect of the invention〕

As explained above, this invention utilizes the gettering action of the deposited layer formed on the inner wall of the tank in the vicinity of the observation window, in which the vapor from the gettering evaporation source is transferred to the wall surface once. This has the effect of reducing the number of times the fog is removed by preventing it from evaporating and reaching the observation window and fogging it.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional vapor deposition apparatus. In Figure 2, (1) is the tank, (2a) and (2b) are the main evaporation sources, (3) is the substrate, (5) is the observation window, and (7) is the main evaporation source.
) is an evaporation source for gettering, and (9) is an adsorption wall. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A main evaporation source that is provided in a tank that is shielded from the atmosphere and that emits vapor to form a vapor deposited layer on a substrate placed in the tank, and a main evaporation source that is provided on the wall of the tank and is located inside the tank. an observation window that allows observation of the vapors emitted from the main evaporation source; toward the suction wall and space near the observation window where a vapor airflow exists, and the substrate;
A vapor deposition apparatus comprising: the main evaporation source; and a gettering evaporation source that emits water while avoiding the observation window.