JPH04350926A - heat treatment equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus that performs various heat treatments such as oxidation, diffusion, and film formation on wafers in the manufacturing process of ICs and LSIs.

0002

2. Description of the Related Art Heat treatment apparatuses equipped with so-called vertical furnaces or horizontal furnaces have been used to perform various heat treatments on wafers such as silicon wafers. The inside of this furnace is heated to, for example, about 1000°C, and the room temperature is, for example, 23°C.
Therefore, when loading and unloading wafers into this furnace, the speed of loading and unloading must be adjusted to prevent deformation of the wafers due to sudden temperature changes. It is done slowly and slowly.

0003

[Problems to be Solved by the Invention] As described above, since the speed of charging into and taking out of the furnace is slowed down, the throughput of this furnace is significantly reduced. For example, the movement stroke for loading and unloading from the furnace is 1
000mm, the speed of charging into the furnace and taking it out from the furnace is 50mm.
mm/min, and the time required for heat treatment is 4 hours, this means that the operating rate of the furnace is reduced by about 15% due to this charging and unloading.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide a heat treatment apparatus that improves the operating rate of a furnace.

[0005]

[Means for Solving the Problems] A heat treatment apparatus of the present invention for achieving the above object includes a heat treatment furnace for heat-treating wafers, a heat treatment furnace for preheating the wafers before being loaded into the heat treatment furnace, and a heat treatment furnace for preheating the wafers before being loaded into the heat treatment furnace. The apparatus is characterized in that it includes a preheating and slow cooling chamber for slow cooling the wafer taken out from the wafer.

[0006]

[Operation] The heat treatment apparatus of the present invention is equipped with the preheating and slow cooling chamber in addition to the heat treatment furnace, so that the wafer can be heat-treated at high speed by preheating the wafer before it is loaded into the heat treatment furnace. The wafer can be loaded into the furnace, and the wafer loaded in the heat treatment furnace can be taken out at high speed and then slowly cooled, thereby improving the operating rate of the heat treatment furnace.

[0007]

[Examples] Examples of the present invention will be described below. FIG. 1 is a schematic diagram of a heat treatment apparatus according to an embodiment of the present invention. This heat treatment apparatus consists of a cassette 40 loaded with wafers 1;
A heat treatment chamber 10 is loaded with the wafers 1 and heat-treated the wafers 1; a cassette 40 is loaded with the wafers 1;
The cassette 40 includes a preparation chamber 20 for taking out the wafers 1 loaded in the cassette 40, and a preheating and slow cooling chamber 30 for preheating and slowly cooling the wafers 1 loaded in the cassette 40.

The heat treatment chamber 10 is equipped with a quartz tube 11 and a heater 12. A cassette 40 loaded with wafers 1 is inserted into the quartz tube 11, and the gas flowing through the gas introduction pipe 13 is inserted into the quartz tube 11. Predetermined heat treatment is performed in an atmosphere. Further, in the preparation room 20, wafers 1 transferred from the outside are loaded into the cassette 40, and wafers 1 loaded in the cassette 40 are taken out to the outside.

Further, a gas exhaust pipe 14 is installed inside the preheating and slow cooling chamber 30, and a quartz tube 1 of the heat treatment chamber 10 is connected to the gas exhaust pipe 14.
The temperature inside the preheating and slow cooling chamber 30 can be gradually raised and lowered by using the residual heat of the exhaust gas after passing through the preheating and slow cooling chamber 30 by a control device (not shown). Here, this heat treatment apparatus includes a cassette 40 into which wafers 1 are loaded.
There are two cassettes 4 in the preparation room 20.
It is configured so that two 0's can be placed side by side. Hereinafter, the two cassettes 40 will be referred to as a cassette 41 and a cassette 42 to distinguish them from each other.

FIG. 2 is a process diagram for performing heat treatment using the heat treatment apparatus shown in FIG. In this process diagram, (
a) and (b) show each lot of heat treatment, (1) and (2)
), ..., (11) indicate each processing step of each lot. Below, each processing step (1) for lot (a) will be explained.
), (2), ..., (11). (1) First, with both the cassettes 41 and 42 placed in the preparation room 20, the wafer 1 transported from the outside is loaded into one of the cassettes 41. (2) Next, the cassette 41 loaded with the wafers 1 is transferred to the preheating annealing chamber 30, and (3) the temperature of the wafers 1 loaded in the cassette 41 is gradually raised to about 500°C. Also, during this time, the space between the preheating slow-cooling chamber 30 and the preparation room 20 is left open, and the preparation room 2
The temperature inside 0 is also close to the temperature inside the preheating slow cooling chamber 30, for example 4.
It is preferable to raise the temperature to about 00°C. (4) Next, the cassette 41 loaded with the wafer 1 is returned from the preheating annealing chamber 30 to the preparation chamber 20, and (5)
Subsequently, the cassette 41 is loaded into the heat treatment chamber 10 maintained at about 1000°C. In this case, cassette 4
Since the wafer 1 loaded into the heat treatment chamber 10 has already been preheated, the speed at which the wafer 1 at room temperature is loaded into the heat treatment chamber 10 is much higher than, for example, 50 mm/min, for example, 25 mm/min.
It can be charged at a speed of about 0 mm/min. (6) The wafer 1 loaded in the cassette 41 loaded into the heat treatment chamber 10 is subjected to heat treatment. (7) The cassette 41 loaded with the wafers 1 that have undergone heat treatment is transferred from the heat treatment chamber 10 to the preparation chamber 20. At this time, the inside of the preparation chamber 20 is maintained at about 400° C., and the material is transferred at a speed of about 250 mm/min. (8) Following this transfer, the cassette 41 is transferred to the preheating annealing chamber 30, and (9) the wafer 1 loaded in the cassette 41 is annealed in the preheating annealing chamber 30. (10) After that, the cassette 41 is returned from the preheating annealing chamber 30 to the preparation chamber 20, and (11) the wafer 1 loaded in the cassette 41 is taken out to the outside.

The first lot (a) goes through each process as described above, but as for the next lot (b), as shown in FIG. The cassette 41 loaded with the wafers 1 that have been processed is stored in the preparation room 20.
The wafer 1 is loaded into another cassette 42 disposed in the preparation chamber 20 while being transferred from the wafer 1 to the heat treatment chamber 10, and then, as in the case of lot (a), the wafer 1 is transferred to the heat treatment chamber 10.
), the steps of transfer to the preheating and slow cooling chamber 30, preheating, and so on are proceeded.

In the above embodiment, the preparation chamber 20 and the heat treatment chamber 10
Since the transfer time of the cassette 40 between the cassette and the cassette 40 is set at 250 mm/min, if the time required for one heat treatment is 4 hours, the operation time will be approximately 7% compared to the case where transfer is performed at the conventional speed of 50 mm/min as described above. This means that the rate can be improved.

[0013]

[Effects of the Invention] As explained above, since the heat treatment apparatus of the present invention is equipped with a preheating and slow cooling chamber separately from the heat treatment furnace,
The wafers can be loaded into the heat treatment furnace at high speed and the wafers can be taken out from the heat treatment furnace at high speed, thereby making it possible to use the heat treatment furnace more efficiently.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a process diagram for performing heat treatment using the heat treatment apparatus shown in FIG. 1;

[Explanation of symbols]

1 wafer
10 Heat treatment chamber 11 Quartz tube
12 Heater 13 Gas introduction pipe
14 Gas exhaust pipe 20 Preparation room
30 Preheating slow cooling chamber 40, 41, 42 Cassette

Claims (1)

[Claims] Claim 1: A heat treatment furnace for subjecting wafers to heat treatment; and a preheating and slow cooling chamber for preheating wafers before being loaded into the heat treatment furnace and slowly cooling wafers taken out from the heat treatment furnace. A heat treatment device featuring: