JPH09232243A - Diffusion furnace apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a diffusion furnace apparatus in which particles are not generated and which restrains the air from being mixed by providing a remaining installation cap which is used to prevent the air from being mixed from a gas exit at a reaction tube and which is constituted so as to be capable of being taken into, and out from, the reaction tube by using a fork. SOLUTION: A diffusion furnace apparatus is constituted mainly of a horizontal quartz reaction tube 20 and of a heater used to heat the reaction tube 20, and it is provided with a remaining installation cap 10 which is used to restrain the air from being mixed from a gas exit 7 as the open end of the reaction tube 20 and which is constituted so as to be capable of being taken into, and out from, the reaction tube 20 by using a fork. The remaining installation cap 10 comprises a rectangular or trapezoidal cutout at the lower part so that the square pillar part of the fork is inserted easily, and it is constituted of three disk-shaped quartz plates whose diameter is smaller than the inside diameter of the reaction tube 20 and of three quartz support rods which are arranged in parallel so as to support and fix the three quartz plates in such a way that their surfaces are faced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a diffusion furnace apparatus.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, a diffusion furnace apparatus is used for forming an oxide film or the like on a semiconductor wafer (hereinafter simply referred to as a wafer) by thermal oxidation. As shown in FIG. 4, a conventional diffusion furnace apparatus includes a quartz reaction tube 20 having a gas introduction tube provided at one end and an open other end,
It was mainly composed of a heater (not shown) for heating the reaction tube. Then, the wafer 5 is placed on the quartz boat 4A, and the gas outlet 7 which is the open end of the reaction tube 20.
It was supposed to be transported inside by a fork.

In the thus constructed diffusion furnace apparatus, since the atmosphere flows into the reaction tube 20 when the wafer is loaded, the wafer 5 is oxidized by oxygen in the atmosphere and contaminated by impurities. As a countermeasure against this, a method of partitioning the gas outlet 7 of the reaction tube with an inner lid made of quartz (actually 3-4
1927) or as shown in FIG. 5, a method of providing a shielding plate 14 on a quartz board holder 13 on which a plurality of quartz boards 12 on which wafers are mounted by grooves 11 is placed (Japanese Patent Laid-Open No. 63-63,631).
No. 62316) has been proposed.

[0004]

However, in the above-mentioned conventional diffusion furnace apparatus, in the method of partitioning the gas outlet of the reaction tube with the inner lid, the quartz inner lid is used for the reaction tube and the projection provided in the reaction tube. Therefore, there is a drawback that particles are generated and adhere to the wafer. Further, as shown in FIG. 5, in the method of providing the shield plate on the quartz board holder, all the quartz board holders corresponding to the size and shape of each quartz board must be redesigned to provide the shield plate. ,
The disadvantage is that the quartz board holder is expensive.

An object of the present invention is to provide a diffusion furnace device which can suppress the mixture of the atmosphere without generating particles by providing a simple jig.

[0006]

The diffusion furnace apparatus of the present invention comprises:
In a diffusion furnace device having a horizontal reaction tube, a boat on which a semiconductor wafer is placed from a gas outlet of the reaction tube is put in and out by a fork, in order to suppress atmospheric mixture from the gas outlet of the reaction tube, It is characterized in that it is provided with a residual cap configured to be able to be put into and taken out of the reaction tube by a fork, and in particular, the residual cap has a plurality of disk-shaped discs each having a notch into which a prism portion of the fork is inserted. And a plurality of support rods that support and fix the quartz plates in parallel so that the surfaces thereof face each other.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a diffusion furnace device for explaining an embodiment of the present invention, showing a case where a boat on which a wafer is placed and a remaining cap are left stationary in a reaction tube.

Referring to FIG. 1, the diffusion furnace apparatus is mainly composed of a horizontal quartz reaction tube 20 and a heater (not shown) for heating the reaction tube. In particular, the residual cap 10 configured to be able to be put in and taken out from the reaction tube 20 by a fork for suppressing atmospheric mixture from the gas outlet 7 which is an open end is provided. 2A and 2B are front views and side views of the remaining cap 10 and the remaining cap 10 shown in FIG. 3 and the wafer 5 mounted on the boat 4 are mounted on a fork. Will be further described with reference to the side view of FIG.

The remaining cap 10 is shown in FIGS. 2 (a) and 2 (b).
As shown in FIG. 3, a rectangular or trapezoidal notch 2 into which the prismatic portion 6B of the fork 6 can be easily inserted is provided, and three disk-shaped quartz plates 1 having a diameter smaller than the inner diameter of the reaction tube are provided. The three quartz plates 1 are arranged in parallel so that their surfaces are opposed to each other, and are supported and fixed by three quartz support rods 3. The remaining cap 10 is placed on the prismatic portion 6B of the fork 6 after the quartz boat 4 on which the wafer 5 is placed is placed on the spatula portion 6A of the fork 6. As shown in FIG. 1, the boat 4 and the remaining cap 10 are allowed to stand in the reaction tube 20 by the fork 6 (soft landing).
Then, the heat treatment and the oxidation treatment of the wafer 5 are performed.

As described above, according to the present embodiment, when the boat 4 on which the wafer 5 is placed is transferred into the reaction tube 20, the remaining cap 10 shields the gas outlet 7 of the reaction tube 20. Therefore, it is possible to prevent unnecessary atmosphere from being mixed into the gas in the furnace during the entrance of the wafer 5. For example, when the inner diameter of the reaction tube is 220 mm and the radius of the quartz plate 1 is 180 mm in order to easily insert the remaining cap 10 into the reaction tube 20 without contacting it, the remaining cap 10
It is possible to block the gas outlet 7 of the reaction tube 20 by about 67%, and it is possible to greatly suppress the mixture of the atmosphere.

In the above embodiment, the case where the remaining cap is composed of the three quartz plates 1 and the three support rods 3 has been described, but the present invention is not limited to this, and two or more sheets are used. The remaining cap may be constituted by the quartz plate and two or more support rods.

[0012]

As described above, according to the present invention, since the residual cap 5 is provided so that it can be put into and taken out of the reaction tube by the fork, the mixture of the atmosphere into the reaction furnace is suppressed without generating particles. There is an effect that a diffusion furnace device that can be obtained can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a diffusion furnace device for explaining an embodiment of the present invention.

FIG. 2 is a front view and a side view of a residual cap.

FIG. 3 is a side view of the fork when the remaining cap and the boat are placed.

FIG. 4 is a sectional view of an example of a conventional diffusion furnace device.

FIG. 5 is a perspective view of a quartz board holder used in a conventional diffusion furnace device.

[Explanation of symbols]

 1 Quartz Plate 2 Notch 3 Support Rod 4, 4A Boat 5 Wafer 6 Fork 6A Spatula 6B Square Column 7 Gas Outlet 10 Remaining Cap 11 Groove 12 Quartz Board 13 Quartz Board Holder 14 Shielding Plate

Claims (2)

[Claims] 1. A diffusion furnace apparatus having a horizontal reaction tube, in which a boat on which a semiconductor wafer is placed is taken in and out from a gas outlet of the reaction tube by a fork, and atmospheric mixing from a gas outlet of the reaction tube is suppressed. A diffusion furnace device for the purpose of comprising a remaining cap configured to be able to be taken in and out of the reaction tube by the fork. 2. The remaining cap comprises a plurality of disk-shaped quartz plates having a notch in which a prism portion of a fork is inserted in the lower portion, and a plurality of quartz plates arranged in parallel so as to face each other and supported and fixed. The diffusion furnace apparatus according to claim 1, comprising a support rod.