JPH0732143B2 - Semiconductor wafer heat treatment equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a semiconductor wafer heat treatment apparatus such as a diffusion apparatus and a CVD apparatus, and particularly to a semiconductor wafer suitable for continuously and uniformly heat-treating a large number of wafers. Of the heat treatment device.

[Conventional technology]

The conventional device, as described in JP-B-59-36417,
The wafer is inserted from one end of the cylindrical heater, heat treatment is performed in the process of continuous movement in the heater, and the wafer is taken out from the other end of the cylindrical heater.

However, when the upper end of the heater is open, the high temperature gas in the heater flows out through the opening due to buoyancy, and no consideration has been given to the problem that low temperature outside air enters the heater due to the outflow.

In addition, as described in JP-A-60-171723, each wafer is inserted into the high temperature furnace from below the vertical cylindrical heater whose bottom is opened, and the wafer is moved upward and heat-treated, and then downward again. It moved to and was taken out from the lower opening. However, if the time to insert into the heater and heat treatment becomes long,
No consideration was given to the problem that the number of wafer heat treatments per unit time decreases and the processing efficiency decreases.

[Problems to be Solved by the Invention]

In the above-mentioned conventional technique, the method of continuously inserting the wafer from one end of the cylindrical heater and taking out the wafer after the heat treatment from the other end has a problem that the heat treatment temperature in the wafer surface fluctuates due to invasion of outside air into the heater. It was Further, the method of inserting the wafers one by one from the lower end of the cylindrical heater and taking out the wafers after the heat treatment from the lower end also has a problem that the outside air intrusion into the heater is small, but the number of heat treatments per hour is small. .

It is an object of the present invention to provide a heat treatment apparatus for a semiconductor wafer, which requires a large number of wafers to be processed per hour and small invasion of outside air into the heater when the wafers are continuously heat-treated for a relatively long time.

[Means for Solving the Problems]

In order to achieve the above object, a semiconductor wafer heat treatment apparatus of the present invention is a semiconductor wafer heat treatment in which a heater is provided on an inner wall of a container to form a high temperature furnace, and the semiconductor wafer is housed in the high temperature furnace to perform heat treatment. In the apparatus, an opening is provided in the lower part of the high-temperature furnace to allow movement of an even number of semiconductor wafer stacked bodies in which the semiconductor wafers are arranged in a stack, and the semiconductor wafer stacked body is provided with an opening from outside the high-temperature furnace. An insertion mechanism for inserting a semiconductor wafer, a take-out mechanism for taking out the semiconductor wafer to the outside of the high temperature furnace, a drive mechanism for vertically moving the plurality of semiconductor wafer stacked bodies, and the semiconductor wafer in the high temperature furnace A semiconductor wafer moving means for transferring semiconductor wafers between the stacked bodies is provided, and the semiconductor wafer stacked body is transferred by the semiconductor wafer moving means. Body is characterized in that to perform the wafer top surface of.

[Action]

By using a high temperature furnace that is closed except for the bottom end opening,
The hot gas in the furnace does not flow out to the outside due to buoyancy, so that the outside air does not enter the furnace. In addition, since the semiconductor wafers are arranged in a reverse U-shaped space path in a laminated manner and sequentially moved in the furnace, a large number of wafers can be arrayed and housed in the furnace, and even if a heat treatment is performed for a long time, The number of heat treatments can be increased.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a vertical sectional view of a semiconductor wafer heat treatment apparatus.

The upper ends of the two cylindrical high temperature furnaces 11 and 21 are closed by walls, and the lower ends are open. Both of the high temperature furnaces 11 and 12 have resistance heating wires wound in a coil shape on the inner wall thereof, and are provided with heaters 12 and 22 formed in a cylindrical shape as a whole, and the outsides thereof are covered with furnace bodies 15 and 25 of a heat insulating material. ing. Inside the heater, a cylindrical heat equalizing tube 13,23 made of silicon carbide or alumina etc.
, And the reaction tubes 14 and 2 made of quartz glass inside.
4 are arranged. The lower ends of the reaction tubes 14 and 24 are open, the upper ends are closed by a wall, and a flat communication path 10 that connects the reaction tubes 14 and 24 is provided at a position slightly lower than the upper ends. As a horizontal movement mechanism, for example, a rotary bar 18 for moving the wafer between the reaction tubes 14 and 24 is provided in the center of the lower wall of the 10.
Is connected to the motor 18b, and the seal 10a is
Is provided. An inverted U-shaped space path is formed by both the reaction tubes 14 and 24 and the communication path 10. Boats 16 and 26 shown in detail in FIG. 2 are arranged in the reaction chambers 14 and 24. Drive mechanisms 17, 27 are provided at the lower ends of the boats 16, 26.
Reference numerals 19 and 29 denote an inserting mechanism and an ejecting mechanism for inserting and removing the wafer 1 into and from the boats 16 and 26.

FIG. 2 shows the details of the boat. The figure illustrates one boat 16. Boat has two rectangular frames 31,32
This frame is composed of a long piece 31a and a short piece 31b, and a first frame 31 in which a large number of facing grooves 33 are formed in the facing long piece 31a, and the length of the long piece is the above-mentioned long piece. The long piece 32a and the short piece, which are slightly shorter than 31a, are formed in a rectangular shape by the short piece 32b having the same length, and the second frame 32 provided with a large number of similar grooves 34 is provided. Drive mechanism 1
7a and 17b are provided. Since the long lengths of the two frames 31 and 32 are different, the second frame 32 is arranged inside the first frame 31 in the orthogonal direction as shown in the figure, and both frames can be moved in the vertical direction via the drive mechanism. Has been formed.

Incidentally, a large number of grooves 33, 34 provided on the opposing long pieces are grooves for inserting and mounting a wafer, and the wafers are inserted into the respective grooves 33, 34 and arranged in a laminated form on a frame. Although the boat 16 has been described as being on the high temperature furnace 11 side, the boat on the other high temperature furnace 12 side is described.
26 also has a completely similar structure.

In the heat treatment apparatus having the above structure, the reaction tubes 14 and 24 and the space path in the communication passage 10 are filled with nitrogen, depending on the usage conditions of the heat treatment apparatus.
Gases such as argon, oxygen and water vapor are flowing. still,
In the apparatus shown in FIG. 1, the gas supply pipe and the exhaust pipe for the above-mentioned space path are omitted.

The operation of the heat treatment apparatus formed as described above will be described. First, the operation of placing the wafers 1 in a stacked manner on the boat and the operation of moving the wafers will be described with reference to FIGS. 3 to 5. The figure shows a horizontal cross-section of the boat shown in FIG.

First, it is assumed that wafers are stacked and arranged in the boat 16 on the side of the high temperature furnace 11 on one side.

The first frame 31 is moved in the X direction as shown in FIG. 3, the frame 31 is brought close to the short portion of the frame 32, and the groove 33 is removed from the wafer 1.
Remove. The first frame 31 is connected to the groove 33 via the drive mechanism 17a.
Lower by half the pitch of the second frame 32 at the same time
Is raised by a half of the groove pitch via the drive mechanism 17b, and then the wafer 1 is replenished and inserted into the lower groove 34 of the second frame 32 via the insertion mechanism 19. Then the first frame 31
Is returned in the X direction, the groove 33 is inserted in the wafer 1, and the wafer 1 is moved to the central portion of the wafer 1 as shown in FIG. As a result of the above operation, the wafers stacked in the frame are raised by one step in the groove, and one wafer is replenished and inserted in the groove in the lowermost step.

Next, the second frame 32 is moved to X as shown in FIG.
Direction, move the frame 32 to the end of the frame 31,
The groove 34 is removed from the wafer 1, the second frame 32 is lowered by a half pitch, and at the same time, the first frame 31 is raised by a half pitch, and then the wafer 1 is replenished and inserted into the lower groove 33 of the first frame 31. Next, the second frame 32 is returned in the Y direction, the wafer 1 is inserted into the groove 34, and then moved to the central portion of the wafer as shown in FIG. As a result of the above operation, the stacked wafers are further raised in the groove by one step, and one wafer is replenished and inserted into the lowest groove. By repeating the above operation continuously, the wafers 1 stacked in the boat 16 are raised one by one, and at the same time, the wafers are replenished and inserted one by one into the open groove in the lower stage. The wafer that has risen to the uppermost groove of the boat 16 is moved in the flat communication furnace 10 by the rotating bar 18 of the horizontal moving mechanism, and is transferred to the uppermost groove of the boat 26 of the other high temperature furnace 21.

Next, the wafer inserted into the groove of the frame of the boat 26 is
By performing the action opposite to the above-described ascending action, it is sequentially lowered one step at a time and taken out by the take-out mechanism 29 from the groove at the bottom. As described above, the wafer is annealed while continuously passing through the inverted U-shaped space paths of the high temperature furnaces 11 and 21. Soaking tubes 13 and 23 are heaters 12 and 22 of high temperature (about 1000 degrees C)
It acts to prevent the impurity molecules from jumping out of the wafer and contaminating the wafer. The reaction tubes 14 and 24 allow gas to flow into the tubes to prevent dust from adhering to the wafer.

According to this embodiment, since the wafers are continuously moved side by side on the central axis of the heater, the heating process of the wafers becomes uniform in the circumferential direction, and the thermal history within the wafer surface can be made uniform.

FIG. 6 shows a vertical sectional view of a heat treatment apparatus according to another embodiment of the present invention. Large diameter vertical high temperature furnace 41, cylindrical heater 42, soaking tube 4
3. It is composed of a reaction tube 44 closed by an upper wall and a heat insulating material 45 for the furnace body. Two boats 46 and 47 are inserted into one cylindrical reaction tube 44 that is sealed except for the lower end, and the wafers 1 are stacked on the boats 46 and 47. The structure of each boat is the same as that shown in FIG. The boats 46 and 47 are provided with an insertion mechanism 19 for loading and unloading the wafer 1, a unloading mechanism 29, and a horizontal movement mechanism 48 for moving the wafer from one boat 46 to the other boat 47.

Using the heat treatment apparatus configured as described above, when performing heat treatment on the wafers 1 that are continuously inserted, the operation is the same as in the first embodiment described above.
This is the same as the illustrated embodiment.

According to the present embodiment, at the upper ends of the boats 46 and 47, the wafers can be moved from one boat 46 to the other boat 47 in the uniform temperature space within the same heater 42.
The thermal history of the wafer can be made more uniform.

FIG. 7 is a vertical sectional view of a processing apparatus showing still another embodiment. This embodiment is different from the embodiment shown in FIG. 6 in that the wafers 1 are placed one by one in a cartridge 51 and a high temperature furnace is used.
It has a structure for moving the inside of 41 and a moving mechanism 52 for moving the cartridge horizontally in the lower part as well, and the other parts are the same as those in the embodiment of FIG. Is attached and its description is omitted.

FIG. 8 shows a perspective view of the cartridge 51. A wafer is taken out from the lower cartridge 51 of the cartridge row 51b by the taking-out mechanism 29, and an empty cartridge is horizontally moved 52.
Is moved to the lowermost stage of the cartridge row 51a, and the wafer 1 is placed on the empty cartridge 51a 'by the insertion mechanism 19. The cartridge 51 containing the wafer is sequentially moved upward by the drive mechanism 17. The cartridge that has reached the upper end of the cartridge row 51a is moved to the adjacent cartridge row 51b by the horizontal movement mechanism 48. Next, the wafer 1 is sequentially moved downward via the drive mechanism 27, and the wafer 1 is taken out from the cartridge 51 by the take-out mechanism 29 at the lower end. The empty cartridge moves horizontally to the cartridge row 51a side by the horizontal mechanism 52, a new wafer is inserted, and the above operation is repeated.

According to the present embodiment, since the wafers are housed in the cartridge one by one and heated, the mutual interference between the wafers is small, and the heat treatment can be performed more uniformly.

In the description of each of the above-described embodiments, the wafers arranged in a stack in the high temperature furnace have the same wafer arrangement pitch during the upward movement and the downward movement, but this arrangement pitch may be different. Good. That is, by moving upward, the wafer that has reached the upper end of the ascending row is horizontally moved to the descending row, and then it is rapidly moved downward and can be taken out as it is.

〔The invention's effect〕

According to the present invention, by continuously arranging wafers in a stack in a high-temperature furnace, it is possible to increase the number of heat treatments in a small size even when heat treatment for a relatively long time is required. . In addition, since the outside air does not enter the heater, the heat history of the wafer can be made uniform, and the power consumption can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a heat treatment apparatus showing an embodiment of the present invention, FIG. 2 is a perspective view of a port portion of FIG. 1, and FIGS. 3 to 5 are ports. 6 is a horizontal sectional view for explaining the operation of FIG.
FIG. 7 is a vertical sectional view of a heat treatment apparatus showing another embodiment, FIG. 7 is a vertical sectional view of a heat treatment apparatus showing still another embodiment, and FIG. 8 is a perspective view of a cartridge. 1 ... Wafer, 11, 21, 41 ... High temperature furnace, 10 ... Communication passage,
14, 24 …… Reaction tube, 16,26,46,47 …… Port, 17,27
...... Drive mechanism, 18, 48, 52 …… Rotary bar, 19 …… Insertion mechanism, 29 …… Ejection mechanism, 31, 32 …… Frame, 51 …… Cartridge.

Claims (3)

[Claims] 1. A semiconductor wafer heat treatment apparatus in which a heater is provided on an inner wall of a container to form a high temperature furnace, and a semiconductor wafer is housed in the high temperature furnace for heat treatment, the semiconductor wafer is provided below the high temperature furnace. And an insertion mechanism that inserts the semiconductor wafer into the semiconductor wafer stack from outside the high-temperature furnace, and an opening that allows an even number of semiconductor wafer stacks arranged in a stack to be moved. A take-out mechanism for taking out the semiconductor wafer, a drive mechanism for vertically moving the plurality of semiconductor wafer stacked bodies, and a semiconductor wafer moving means for transferring semiconductor wafers between the semiconductor wafer stacked bodies in the high temperature furnace. And the semiconductor wafer moving means transfers the semiconductor wafer laminated body with respect to the uppermost wafer of the semiconductor wafer laminated body. Heat treatment apparatus of the semiconductor wafer to symptoms. 2. The laminated body of semiconductor wafers comprises two rectangular frames of different lengths having a large number of grooves for mounting the semiconductor wafers, and these two frames are arranged orthogonally to each other. The heat treatment apparatus for a semiconductor wafer according to claim 1, wherein the heat treatment apparatus is provided so as to be movable in the orthogonal axis direction and the vertical direction. 3. The heat treatment apparatus for a semiconductor wafer according to claim 1, wherein the semiconductor wafer moving means is a horizontal movement mechanism having a rotating bar.