JPS6336524A - Apparatus for heat-treating wafer - Google Patents

Abstract

PURPOSE:To prevent various problems due to increase in oxygen concentration and to prevent adherence of particles to the surface of wafers, by providing a cylindrical moving pipe for covering a gas supply pipe or the like having small holes and provided over a wafer receiving boat, and providing a gas curtain at the inlet/outlet port of a core tube. CONSTITUTION:A gas supply pipe 2 is provided in the upper portion of a cylindrical moving pipe 1. The gas supply pipe 2 is provided with a multiplicity of small holes 3 so that gas is ejected therefrom as indicated by the arrows 9. In the lower portion of the cylindrical moving pipe 1, a plurality of grooves 20 are provided longitudinally so that wheels 5 of a puddle 7 are engaged in the grooves so as to introduce the puddle in or withdraw it out of the pipe 1. Further, a withdrawing rod 10 and a screen plate 4 are provided. In a core tube section, there are provided a furnace body 15 and a core tube 18. A gas curtain 12 is arranged at the inlet/outlet port of the core tube. Gas 11 is introduced into the core tube through a gas supply port 13 while air is prevented from entering into the core tube by ejected gas 14. The puddle is conveyed by a cylindrical cantilever beam system so that a heavy weight load can be inserted into or withdrawn from the furnace only by moving it transversely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wafer heat treatment bag k, and particularly to a wafer heat treatment apparatus suitable for thermal diffusion or CVD of large diameter wafers.

[Conventional technology]

Conventionally, the wafer transfer technology of this type of wafer heat treatment apparatus for thermal diffusion or CVD of wafers is as shown in FIG. The paddle 7 on which the wafer 8 is placed is constituted by a pull-out rod 10 and a paddle pull-out device 21 on which the paddle is placed, and is taken in and out of the furnace core tube 18 by the paddle pull-out device. In addition, in the figure, 15 is a furnace body;
18 is a furnace core tube, 29.26 and 22.23 degrees 24 are arrows showing the movements of a pull-out rod and a paddle pull-out device. The operation is such that when the paddle pull-out device enters the furnace core tube and reaches a predetermined position within the furnace core tube, it is lowered, the paddle is lowered from the pull-out device, and the pull-out device is taken out of the furnace core tube together with the pull-out rod. Note that the paddle pull-out device is inserted to the front of the wafer at a predetermined position.

[Problem that the invention seeks to solve]

In the conventional wafer transport technology described above, when the wafer is taken out of the furnace core tube, it comes into direct contact with the air, and comes into contact with floating dust in the air, resulting in particle contamination. In addition, as the wafer diameter increases, the weight increases, which leads to problems with the strength of the mechanism and paddle pull-out device, and a large amount of air enters the furnace from the furnace mouth, causing problems with polycrystalline silicon contact during thermal diffusion and CVD growth. In addition, the problem of oxygen concentration in the furnace becomes a major factor, and air flows into the furnace core tube, resulting in contamination inside the furnace core tube.

The purpose of the present invention is to avoid problems with the strength of the mechanical part and paddle pull-out device even when the wafers have a large diameter and become heavy, and also to avoid problems caused by a large amount of air entering from the furnace mouth and an increase in oxygen concentration in the furnace. It is an object of the present invention to provide a wafer heat treatment apparatus that can solve various problems and prevent particles from adhering to the wafer surface due to contact with air when the paddle is pulled out together with the wafer from the furnace core tube.

[Means for solving problems]

The wafer heat treatment apparatus of the present invention includes a paddle on which a boat containing large-diameter wafers is placed, a plurality of guide holding pieces that support the paddle and facilitate insertion and removal, and a plurality of guide holding pieces installed on the guide holding piece. a gas supply pipe installed in the upper part of the wafer storage boat and provided with a microhole, a pull-out rod for pulling out the paddle, a shield that interlocks with the pull-out rod, and a wheel that covers the above-mentioned parts. It is constructed by having a wafer handling device equipped with a cylindrical moving pipe having a plurality of grooves that can be inserted in the longitudinal direction, and a gas curtain provided at the entrance and exit of the furnace core tube.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. 1(a) to 1(c) are schematic cross-sectional views of one embodiment of the present invention, in which FIG. 1(a) is a furnace core tube section, FIG. 1(b) is a wafer handling device, and a first embodiment of the present invention. Figure (C) is an enlarged river view of section A.

In FIGS. 1(a) to 1(c), a gas supply pipe 2 is provided in the upper part of the inside of the cylindrical moving pipe 1, and the gas supply pipe 2 is provided with a large number of pores 3 so that the gas is It is designed to blow out like 9. A guide holding piece 6 is installed on the paddle 7 on which the board I-19 containing the silicon wafer 8 is placed, and a wheel 5 is installed on the guide holding piece. Note that a paddle 7 is provided at the bottom of the cylindrical moving pipe 1.
A plurality of grooves 20 are provided into which wheels can be inserted and removed in the longitudinal direction. Further, 10 is a pull-out rod, and 4 is a shielding plate interlocked with the pull-out rod, and the above constitutes a wafer handling device section.

On the other hand, 15 of the furnace core tube section is a furnace body, and 18 is a furnace core tube. A gas curtain 12 is installed at the entrance and exit portion of the furnace core tube, gas 11 is introduced through a gas supply port 13, and the blowing gas 14 blocks incoming air.

In the above-described wafer heat treatment apparatus, a plurality of wrinkled wafers 8 placed on a bow 1-19 are placed on a paddle 7, and the paddle is housed inside a cylindrical transfer pipe 1. A gas supply pipe having a large number of pores 3 is installed in the upper part of the pipe, and atmospheric gas is supplied through the large number of pores 3 to maintain the atmosphere inside the cylinder.

Furthermore, a movable shield plate is provided at the rear of the paddle in conjunction with the pull-out rod to prevent atmospheric gas from leaking out. In addition, a cylindrical cantilever structure is used as the structure for conveying the paddle, making it possible to convey heavy objects, and the mechanism allows the paddle to be inserted into the furnace by only moving back and forth (in the longitudinal direction).

In addition, a cylindrical atmosphere gas curtain is provided at the furnace core pipe port to prevent air from entering, and the inside of the cylindrical transport pipe with a paddle mounted thereon is inserted into and removed from the furnace. Double air isolation from the atmospheric gas blown out from the gas supply pipe installed at the top of the tank is possible.

With the above configuration, the wafers housed in the boat on the paddle are put into the cylindrical transfer pipe, filled with atmospheric gas, and inserted into the furnace core tube at a fixed position, and then transferred to the paddle and the boat on the paddle. The accommodated silicon wafers are left in place and the others are taken out of the furnace core tube. After processing, the removed portion is replaced with atmospheric gas and then placed into the furnace core tube, allowing the silicon wafer to be removed without coming into contact with the oxygen atmosphere.

〔Effect of the invention〕

As explained above, in the present invention, even when the wafer size increases and the weight increases, the cylindrical cantilever structure allows the high-purity heat-resistant material to sufficiently withstand the load.

In addition, as the wafer size increases, the oxygen concentration inside the furnace core tube is likely to become abnormal, but in the present invention, a gas curtain is installed at the entrance and exit of the furnace core tube to cut off air flowing into the furnace core tube and lower the oxygen concentration. No underlying problems occur.

Furthermore, when the paddle is pulled out from the furnace core tube together with the wafer, particles may adhere to the wafer surface due to contact with air. Since the atmospheric gas is blown out, a clean atmosphere can be maintained, so that particles do not adhere to the wafer surface. You can obtain many effects such as.

[Brief explanation of drawings]

FIGS. 1(a), (b), and (c) are a sectional view and an enlarged side view of part A of one embodiment of the present invention, and FIGS. 2(a) and (b) are of a conventional wafer heat treatment apparatus. It is a sectional view of an example. 1... Cylindrical conveyance pipe, 2... Gas supply pipe, 3... Pore, 4... Shield plate, 5... Wheel, 6...
- Holding piece for guide, 7... Paddle, 8... Silicon wafer, 9.14... Gas blowing arrow, 10... Pull-out rod, 11.13... Gas supply port, 12... Gas curtain, 15...furnace body, 16...in/out direction, 1
7... Atmosphere gas, 18... Furnace core tube, 19... Boat, 20... Vortex. Agent: Susumu Uchihara, patent attorney

Claims (1)

[Claims] a paddle for placing a boat that accommodates large-diameter wafers;
a plurality of guide holding pieces that support the paddle and facilitate insertion and removal; and wheels installed on the guide holding pieces;
A gas supply pipe installed in the upper part of the wafer storage boat and equipped with a microhole, a pull-out rod for pulling out the paddle, a shielding plate that interlocks with the pull-out rod, and a wheel that covers the above-mentioned parts so that it can be inserted in the longitudinal direction. A wafer heat treatment apparatus comprising: a wafer handling apparatus equipped with a cylindrical transport pipe having a plurality of grooves; and a gas curtain provided at an entrance and exit of a furnace core tube.