JPH0648678B2 - Wafer heat treatment equipment - Google Patents

Description

The present invention relates to a wafer heat treatment apparatus, and more particularly to a wafer heat treatment apparatus suitable for thermal diffusion or CVD of large diameter wafers.

[Conventional technology]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a wafer transfer technique of a wafer heat treatment apparatus for thermal diffusion or CVD of a wafer of this type has been shown in FIG. 2 in which silicon wafers are mounted on a plurality of boats 19 mounted on paddles 7 having wheels 5. 8 is placed, and the paddle 7 is composed of 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 the figure, 15 is a furnace body,
Reference numeral 18 is a furnace core tube, and reference numerals 29, 26 and 22, 23, 24 are arrows showing the movements of the drawing rod and the paddle drawing device. The operation is such that when the paddle drawing device enters the furnace core tube and reaches a predetermined position in the furnace core tube, the paddle draws down, lowers the paddle from the drawer device, and the drawer device is taken out of the furnace core tube together with the drawer rod. The paddle drawing device is inserted from a predetermined position on the wafer to the front side.

[Problems to be solved by the invention]

In the conventional wafer transfer technique described above, when a wafer is taken out of the furnace core tube, the wafer is directly contacted with the air, which is in contact with suspended dust in the air, causing particle contamination. Also, the problem of strength of the mechanical part and the paddle drawing device due to the fact that the wafer diameter becomes large due to the large diameter, a large amount of air enters the furnace from the furnace port, and the polycrystalline silicon contact property 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, so that the furnace core tube is contaminated.

The object of the present invention is that there is no problem in the strength of the mechanical unit and the paddle drawing device even if the wafer becomes a large-diameter wafer and becomes heavy, and a large amount of air enters from the furnace port and the oxygen concentration in the furnace increases. It is an object of the present invention to provide a wafer heat treatment apparatus capable of preventing particles from adhering to the surface of the wafer by coming into contact with air when the paddle is pulled out from the furnace core tube together with the wafer.

[Means for solving problems]

The wafer heat treatment apparatus of the present invention includes a paddle for mounting a boat that accommodates large-diameter wafers, a plurality of guide holding pieces that support the paddle and facilitate insertion and removal, and are installed on the guide holding pieces. Wheel, a gas supply pipe provided at the upper position of the wafer accommodating boat and provided with minute holes, a pull-out rod for pulling out the paddle, a shield plate interlocking with the pull-out rod, and a wheel covering the above portion. The wafer handling device is provided 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 inlet / outlet 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 an embodiment of the present invention, in which FIG. 1 (a) is a furnace core tube portion, and FIG. 1 (b).
Is a wafer handling device, and FIG. 1 (c) is an enlarged side view of part A.

In FIGS. 1A to 1C, a gas supply pipe 2 is provided in an upper portion inside a cylindrical moving pipe 1, and a large number of pores 3 are provided in the gas supply pipe 2 so that a gas is blown out by a gas arrow. It is designed to blow out like 9. The paddle 7 on which the boat 19 for accommodating the silicon wafer 8 is mounted is provided with a guide holding piece 6, and a wheel is installed on the guide holding piece. A plurality of grooves 20 into which the wheels of the paddle 7 can be inserted and removed in the longitudinal direction are provided in the lower portion of the cylindrical moving pipe 1. Further, 10 is a pull-out rod, 4 is a shield plate interlocking with the pull-out rod, and the wafer handling device section is configured as described above.

On the other hand, 15 of the furnace core tube portion is a furnace body, and 18 is a furnace core tube. A gas curtain 12 is installed at the inlet / outlet portion of the furnace core tube so that the gas 11 is introduced through the gas supply port 13 and the inflowing air is blocked by the blown gas 14.

In the wafer heat treatment apparatus described above, a plurality of silicon wafers 8 placed on the boat 19 are placed on the paddle 7,
The paddle is housed inside a cylindrical transport pipe 1, and a gas supply pipe having a large number of pores 3 is installed above the cylindrical transport pipe, and an atmospheric gas is sent through the large number of pores 3. The inside of the evacuating cylinder is kept in the atmospheric gas.

Further, a movable shield plate is provided at the rear portion of the paddle so as to interlock with the drawer rod to prevent outflow of atmospheric gas. In addition, a cylindrical cantilever structure is adopted as a structure for conveying the paddles, and heavy objects can be conveyed, and the mechanism allows the paddles to be inserted into the furnace only by moving back and forth (longitudinal direction).

In addition, a cylindrical atmosphere gas curtain for preventing the inflow of air is provided at the furnace core port, and when the cylindrical transfer pipe with the paddle is inserted into and removed from the furnace, the inside of the cylindrical transfer pipe described above It is possible to cut off the air twice from the atmospheric gas blown out from the gas supply pipe provided at the upper part of the.

With the above configuration, the wafers accommodated in the boat on the paddle are put into the cylindrical transfer pipe and inserted into the fixed position of the furnace core tube while being filled with the atmospheric gas. The accommodated silicon wafer is left in place and the others are taken out of the furnace core tube. After the treatment, the taken-out portion is replaced with an atmospheric gas and then placed in a furnace core tube so that the silicon wafer can be taken out without being exposed to the oxygen atmosphere.

〔The invention's effect〕

As described above, according to the present invention, even if the wafer size becomes large and heavy, the cylindrical cantilever structure allows the high-purity heat-resistant material to sufficiently bear the load.

Further, since the wafer size becomes large and the oxygen concentration in the furnace core tube tends to become abnormal, in the present invention, a gas curtain is provided at the inlet / outlet of the furnace core tube to block the air flowing into the furnace core tube to reduce the oxygen concentration. No problem occurs.

Further, when the paddle is pulled out from the furnace core tube together with the wafer, particles are caused to adhere to the wafer surface by coming into contact with the air. Since the atmospheric gas is blown out, it can be kept in a clean atmosphere, so that particles do not adhere to the wafer surface. It is possible to obtain various effects such as.

[Brief description of drawings]

FIGS. 1 (a), (b) and (c) are sectional views of an embodiment of the present invention and an enlarged side view of part A, and FIGS. 2 (a) and 2 (b) are examples of conventional wafer heat treatment apparatus. FIG. 1 ... Cylindrical transfer pipe, 2 ... Gas supply pipe, 3
... pores, 4 shield plate, 5 wheels, 6 holding pieces for guides, 7 paddles, 8 silicon wafers, 9, 1
4 ... Gas blow-out arrow, 10 ... Drawer rod, 11, 13
...... Gas supply port, 12 ...... Gas curtain, 15 ...... Furnace body, 16 ...... Access direction, 17 ...... Atmosphere gas, 18 ......
Furnace core tube, 19 ... boat, 20 ... groove.

Claims (1)

[Claims] 1. A paddle for mounting a boat for accommodating large-diameter wafers, a plurality of guide holding pieces for supporting the paddle and facilitating insertion / extraction, and wheels installed on the guide holding pieces. A gas supply pipe installed at the upper position of the wafer accommodating boat and provided with minute holes, a drawer rod for drawing out the paddle, a shield plate interlocking with the drawer rod, and a wheel covering the above portion in the longitudinal direction. A wafer heat treatment apparatus comprising: a wafer handling device having a cylindrical transfer pipe having a plurality of insertable grooves; and a gas curtain provided at a furnace core tube inlet / outlet port.