JPH0143859Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention is based on an impurity diffusion process applied to a semiconductor wafer.
The present invention relates to a quartz glass bell jar used in chemical vapor deposition or vapor phase growth.

(Prior Art) Conventionally, heat treatment for semiconductor wafers has been carried out by placing the wafer in a reaction container such as a quartz glass bell jar, and heating the entire container from the outside, using an external heating method.
Alternatively, it has been carried out using an internal heating type that heats with a heat source installed inside. Transparent quartz glass or semi-transparent quartz glass is used for the reaction vessels used in these.

Generally, transparent quartz glass bell gears have good thermal permeability and are used for external heating types, but in this case, heating energy loss is large and it is not economical.

In contrast, translucent quartz glass bell jars
The glass contains countless microbubbles inside and crystalline quartz remains on the outside surface, but these microbubbles diffusely reflect heat and keep heat transmission low, so it has good internal heat retention.

Therefore, when used as an internal heating type, the thermal efficiency is high, so it is more widely used than the external heating type.

(Problem that the invention aims to solve) However, since translucent quartz glass is practically opaque, it is not possible to see the internal processing status of bell jars made with it, which is inconvenient for process control. . In order to overcome this drawback, conventionally a window was made in a part of the wall of the translucent quartz glass bell jar and a transparent quartz glass plate was welded thereto to create a viewing window or a window for sensor detection.

However, bell gears manufactured using this method are prone to breakage because large strains remain in the welded parts, and large bell gears can cause accidents such as the entire ring resonates and cracks when you try to make a hole in the wall. It had the disadvantage of causing

(Means for solving the problem) As a result of various studies in view of the above-mentioned problems, the present invention was developed as a solution by placing quartz powder in a rotating hollow bottomed cylindrical container and molding it by centrifugal force. After embedding a transparent quartz glass plate at a desired position on the inner surface of the powder layer so that it is flush with the inner surface of the powder layer,
This invention proposes a quartz glass bell jar characterized by having a vitrified powder layer.

(Structure) As shown in FIG. 1, the present invention has a structure in which a window 1 made of transparent quartz glass is provided at a desired position of a bell jar made of semi-transparent quartz glass. The method for manufacturing is as follows.

First, to form the powder layer 2, as shown in FIG. 2, quartz powder is introduced into the interior of the hollow bottomed cylindrical container 3 made of a material with sufficient heat resistance through the supply port 4 while rotating. Formed into a bell jar shape by centrifugal force. Next, as shown in FIG. 3, a transparent quartz glass plate 5 is embedded in the obtained powder layer 2 at a position suitable for a viewing window for process control or a window for sensor sensing. At this time, the inner surface of the transparent quartz glass plate is made to be flush with the inner surface of the powder layer, so that no distortion occurs during the subsequent heat treatment.

Next, when the whole is heated and melted with the arc flame of the heat source 6 and vitrified, the powder layer 2 becomes semi-transparent quartz glass, but the position where the transparent quartz glass plate is embedded becomes a transparent window 1, as shown in FIG. A quartz glass bell jar as shown in is obtained. In this case, there is no change in wall thickness around the window, so no distortion remains, and the manufacturing yield of Berezier is extremely high.

Note that heating and melting should be done only to obtain a bell jar of the required wall thickness, and it is not necessary to completely melt the powder layer.

(Effects of the invention) In this way, the invention embeds a transparent quartz glass plate in the powder layer, which makes it extremely easy to work and can be done accurately. Since there is no residue, it is a bell gear that can be manufactured with high yield. Moreover, this bell jar has an excellent industrial effect that it can be used safely for a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the bell gear of the present invention,
Figures 2 and 3 are explanatory diagrams of the manufacturing process of the bell gear of the present invention. 1... Window, 2... Powder layer, 3... Cylindrical container, 4
... Supply port, 5 ... Transparent quartz glass plate, 6 ... Heat source.

Claims (1)

[Scope of utility model registration request] Quartz powder is placed in a rotating hollow bottomed cylindrical container and shaped by centrifugal force.A transparent quartz glass plate is embedded at a desired position on the inner surface of the powder layer so that it is flush with the inner surface of the powder layer. A quartz glass bell jar characterized by being made by vitrifying a powder layer.