JPS634343B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat treatment method and apparatus for improving the efficiency of heat treatment of semiconductor thin plates and reducing the size of the apparatus.

2. Description of the Related Art Conventionally, in a semiconductor manufacturing apparatus, when a semiconductor thin plate (wafer) is subjected to heat treatment such as diffusion or oxidation, a heat treatment apparatus as illustrated in FIG. 1 is used. This device is roughly composed of a boat transport section 1, a gas exhaust section 2, a furnace body 3, and a gas supply section 4. Furnace core tubes (process tubes) 5 are arranged in multiple stages in the furnace body 3, and each furnace core tube 5 is heated to a desired temperature by a heater or the like (not shown). Further, in the gas exhaust section 2, the extension portion of each core tube 5 is open, so that a boat, which will be described later, can reciprocate into and out of the core tube.

On the other hand, a boat loader 6 is disposed in the boat transport section 1 corresponding to the extension line of each furnace tube 5. Although only the topmost boat loader is shown in the figure, the boat loader 6 has a drive mechanism (not shown) disposed inside the cover 1a, a part of which protrudes outside the cover 1a through a groove 7, and reciprocates in the axial direction of the reactor core tube. a boat drive unit 8 that moves; a boat 9 that is disposed along the axial extension line of the core tube and whose base end is attached to the boat drive unit 8 and that moves in and out of the core tube as the boat drive unit 8 moves; It consists of The semiconductor thin plate 10 to be heat treated is held at the tip of this boat 9.

Processing in such a heat treatment apparatus is performed in the following procedure. That is, as shown in FIG. 2, the semiconductor thin plate mounting jig 11 is placed on the tip of the boat 9 to hold the semiconductor thin plate 10, and then the boat drive unit 18 is operated to move the boat 9 into the reactor core tube 5. to invade. Once the boat has entered the designated position, if the entire boat 9 or its tip is lowered slightly,
The mounting jig 11 is placed on the inner bottom surface of the furnace tube. After that, when the boat 9 is retreated and pulled out from the inside of the core tube 5, only the mounting jig 11 and the semiconductor thin plate 10 are left inside the core tube, so the so-called heat treatment is performed by covering the opening of the core tube. . After the heat treatment has been completed, the semiconductor thin plate is taken out from the reactor core tube by inserting the boat 9 into the reactor core tube again, placing the boat 9 together with the jig 11 on the tip thereof, and pulling out the boat.

Therefore, during this heat treatment, it is necessary to move the boat 9 back and forth into the core tube 5 twice in order to perform one heat treatment, and after setting the semiconductor thin plate in the core tube, a lid must be placed on the opening of the core tube. As a result, there is a problem in that the entire heat treatment process takes a long time and it is difficult to automate these operations.

Furthermore, in the processing method in which the semiconductor thin plate 10 carried into the reactor core tube 5 is left in the reactor core tube together with the mounting jig 11 as described above, the boat 9 and the jig 1 are shown in FIG.
As shown in the cross-sectional structure of No. 1, the jig 11 must be provided with a support leg 12 that collides with the inner bottom surface of the reactor core tube when the boat 9 is slightly lowered.
2 must be formed so that the lower end thereof protrudes below the bottom surface of the boat 9. For this reason, the lower end of the support leg 12 tends to interfere with the inner surface of the furnace tube when carrying in and out of the semiconductor thin plate, and there is a risk of damaging the support leg 12 and the inner surface of the furnace tube. In particular, if the inner surface of the furnace tube is damaged, the chips will mix with the gas inside the furnace tube, making it impossible to perform normal heat treatment. For this reason, conventionally, the inner diameter of the core tube 5 has to be designed to be sufficiently large, which is an obstacle to downsizing the apparatus in which the core tubes are arranged in multiple stages as described above.

Accordingly, an object of the present invention is to provide a heat treatment method and a heat treatment apparatus that reduce the number of man-hours and automate heat treatment operations, improve heat treatment efficiency, and downsize the heat treatment apparatus.

The present invention will be explained below with reference to Examples.

First, the heat treatment apparatus of the present invention will be explained, and then the method of the present invention will be explained based on this heat treatment apparatus.

Fig. 4 shows the configuration of the main parts of the device of the present invention, that is, the configuration of the boat loader.The furnace body with the furnace tube, the gas exhaust section, and the gas supply section are the same as the conventional ones, so explanations are omitted. do. As shown in the figure, the boat drive unit 8A of the boat loader 6A has a movable plate 14 that can reciprocate on two guides 13 provided on the base 18 in the axial direction of the reactor core tube. The feed screw 15 to be screwed is connected to the motor 16.
The movable plate 14 can be moved back and forth by pivoting at . Further, a part of the movable plate 14 protrudes outside the cover through a groove 8 formed in the cover 1a to form a boat fixing plate 17 (see FIG. 1).

The boat 9A, which is formed into a substantially cylindrical shape, has its base fixed to the fixing plate 17 with two belts 18, while the tip side of the boat 9A is supported by rollers 19 provided on the core tube side. As the fixed plate 17 moves, the boat 9A can move in and out of the reactor core tube. This boat 9A is made of a heat-resistant material such as quartz, and as shown in the side profile in FIG. 21,2
By sealing with 2, a mounting table 23 is formed. This mounting table 23 is provided with buttfuls 24 at both ends, and a semiconductor thin plate 1 is provided between each buttful 24.
It is configured such that a mounting jig 11A for placing 0 can be placed thereon. As shown in FIG. 6, the jig 11A fits and supports the semiconductor thin plate 10 in the notch formed in each parallel stem 11b, and supports the mounting table 23.
It is placed on top and is not provided with supporting legs like the conventional one shown in FIG.

On the other hand, approximately the central part of the boat 9A, to be more precise, the part facing the opening of the core tube 5 when the boat 9A enters the core tube 5 shown by the imaginary line in FIG. As shown in FIG. 2, a cylindrical internal lid 26 filled with a heat insulating material 25 such as glass fiber is inserted into the interior space of the boat, while a substantially saddle-shaped inner lid body 26 filled with a heat insulating material 27 inside is inserted into the interior of the boat. The external lid body 28 is fitted onto the outer circumference of the boat 9A. The outer lid bodies 26 and 28 are formed so as to work together to close the opening of the core tube when the boat 9A enters the core tube (although some gaps are left for gas venting). It is. Further, both lids 26 and 28 may be simply placed inside or above the boat 9A, or may be provided in a semi-fixed state.
In the figure, 29 is a vent hole for heated and expanded air.

Next, the method of the present invention using the above-mentioned apparatus will be explained.

Mounting jig 1 is placed on the mounting platform 23 at the tip of the boat 9A.
1A and the semiconductor thin plate 10 on top of this, if the motor 16 is driven, the feed screw 15
The movable plate 14 and the fixed plate 17 are connected to the guide 13 by
The boat 9A is moved in the direction of the reactor core tube 5 along the direction of the reactor core tube 5, and the boat 9A is inserted into the reactor core tube from the tip side. The boat 9A is inserted into the furnace core tube 5 along a somewhat lower side while being supported by the rollers 19. And semiconductor thin plate 10
When the is inserted into the specified position, the boat 9
When A is stopped, both the internal and external lids 26 and 28, which have just moved to the opening position of the reactor core tube, work together to close the opening of the reactor core tube. As a result, even if the reactor core tube is heated in this state, and in some cases heat treatment is performed while passing gas through it, the inside of the reactor core tube remains thermally sealed, resulting in extremely good heat treatment. be able to. After the heat treatment is completed, the boat 9A is pulled out from the furnace core tube, the semiconductor thin plate 10 is unloaded from the boat together with the jig 11A, and the semiconductor thin plate to be treated next is placed in its place along with the jig, and the heat treatment is carried out in the same manner as described above. can be done.

Therefore, with this method, the number of processing steps can be reduced because the boat only needs to be moved back and forth once for one heat treatment, and there is no need to form support legs on the jig for placing the semiconductor thin plate in the reactor core tube. Interference between the inner surface of the reactor core tube and the inner surface of the reactor core tube is less likely to occur, and the diameter of the reactor core tube can be reduced accordingly, allowing the apparatus to be made smaller. Further, in the above-mentioned apparatus, when the boat is inserted into the core tube, the opening of the core tube is automatically closed by the lid provided on the boat, so that the apparatus can be automated.

It goes without saying that the boat loader in the apparatus of the present invention may be modified in various ways in addition to the above-mentioned embodiments.

As described above, the present invention performs heat treatment while the boat carrying the semiconductor thin plate remains inside the reactor core tube, thereby reducing the required number of reciprocating movements of the boat, reducing the number of heat treatment steps, and improving processing efficiency. In addition, since there is no need to unload the semiconductor thin plate and its mounting jig from the boat, the diameter of the reactor core tube can be reduced, and the device can be made more compact. In addition, since the present invention provides a lid on a part of the boat, there is no need to manually close the core tube opening.
In addition to improving processing efficiency, it is also possible to automate the device.

[Brief explanation of the drawing]

Figure 1 is an external perspective view of a conventional heat treatment equipment;
The figure is a side view explaining the conventional work, and Figure 3 is the second
4 is a perspective view of the boat load of the heat treatment apparatus of the present invention, FIG. 5 is a side view of the boat, and FIGS. It is a sectional view corresponding to the - line. 1...Boat transport section, 3...Furnace body, 5...Furnace core tube, 6, 6A...Boat loader, 9,9A...Boat, 10...Semiconductor thin plate, 11, 11A...Jig for mounting , 15...Feed screw, 16...Motor,
23... Placement stand, 26... Internal lid body, 28... External lid body.

Claims (1)

[Scope of Claims] 1. A heat treatment method in which a thin semiconductor plate is carried in and out of a reactor core tube for heat treatment using a boat that can reciprocate in and out of the reactor core tube, wherein the boat is placed inside the reactor core tube so that the boat is placed inside the reactor core tube. 1. A method for heat-treating a semiconductor thin plate, characterized in that the semiconductor thin plate is carried in without contacting the boat, and then the heat treatment is performed while the boat remains in the reactor core tube. 2. A reactor core tube with one end open, a drive part that reciprocates toward the opening of the reactor core tube on an extension line of the reactor core tube, and a thin semiconductor plate fixed to the drive part and capable of mounting a semiconductor thin plate on the tip part, a boat that reciprocates in and out of the reactor core tube without contacting the inner surface of the reactor core tube by the operation of the drive unit; 1. A heat treatment apparatus for semiconductor thin plates, characterized by being provided with an insulating lid body for closing off the semiconductor thin plate. 3. The heat treatment apparatus for semiconductor thin plates according to claim 2, wherein the lid comprises an inner lid inserted into the boat and an outer lid fitted around the outer periphery of the boat.