JPH0351100B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a soft landing device developed for high-temperature heat treatment, and more particularly to a method for correcting the straightness of a fork for loading and unloading workpieces such as wafers into and out of a furnace.

In semiconductor manufacturing processes, heat treatment furnaces are used to perform diffusion, CVD, and annealing treatments on objects to be processed, such as wafers, and therefore a boat loading device for loading and unloading wafers into and out of the furnace is required. Conventionally, this type of equipment has been adopted as equipment based on the boat loader method or equipment based on the paddle method, but with the boat loader method, dust is generated from the contact parts when the wafer jig is moved within the inner tube. It has the disadvantage of causing wafer defects, and in the paddle method, heat treatment is performed with a long rod (paddle) inserted into the inner tube, which causes temperature changes in the furnace, making it impossible to perform heat treatment at a constant temperature. There is a drawback.

For this reason, the applicant has developed and proposed a soft landing device that eliminates these drawbacks. According to this device, a workpiece such as a semiconductor wafer is mounted on the tip of a quartz fork, and the workpiece can be taken in and out of the furnace by moving the fork in and out without coming into contact with the furnace tube. At this time, the forks are kept in a non-contact state with the furnace tube, so no dust is generated, and the objects to be processed can be loaded and unloaded freely in the furnace tube, so they can move freely. The advantage is that the heat treatment can be carried out at a temperature that is lower than that of the conventional one.

By the way, as shown in Fig. 1, the fork used in this soft landing device is made by cutting off approximately 1/3 of the length of one end 2 of a cylindrical member 1 made of quartz, and then removing the remaining portion of the cut off portion. The structure is such that the portion 3 is formed as a mounting portion for a wafer or a wafer jig. Therefore, since the formed fork is made of quartz, it is likely to be bent particularly in the mounting portion 3 due to external temperature changes or temperature changes and external forces. This kind of bending is particularly important when the diameter of the furnace tube is designed to be small as in recent years, and the gap between the furnace tube and the fork is that small. This will cause a problem that the two will come into contact with each other.

When correcting such a bend in a fork, the conventional method is to measure the bend in the fork in advance, apply external force while heating the fork based on that data to straighten it, and then measure again. A method is used to confirm corrections by comparing this with previous data. However, with this method,
In order to read the measurement data of the fork's bending and straighten the fork, there is a great deal of reliance on the intuition and skill of the operator, which results in poor work efficiency and makes it difficult to expect good and uniform correction. There's a problem.

Therefore, the purpose of the present invention is to determine the position of a laser beam based on jigs placed at two points on the fork, and to check the degree of bending of the fork using this laser beam and a movable jig that moves within the fork. It is an object of the present invention to provide a correction method capable of performing a good and uniform correction without requiring the intuition or skill of an operator by correcting the straightness of a fork.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 shows a soft landing device having a fork, which is the object of the present invention, and this device 10 is installed adjacent to the opening side of a quartz inner tube 11 of a heat treatment furnace, the detailed illustration of which is omitted. The wafers 13 arranged and placed on the wafer jig 12 can be carried into the furnace tube 11 together with the wafer jig 12 and taken out. That is, the soft landing device 10 has a base 14 and a back wall 15 erected at the rear of the base. A pair of guide rails 16, 16 extending from one side to the other are arranged above and below. This guide rail 16,1
A support stand 17 is slidably fitted into the support stand 17, and a feed shaft 18 supported on the back wall 15 in parallel with the guide rail and rotatably supported on the block 17a formed in a part of the support stand 17. It is inserted. This feed shaft 18 is rotated by connecting a belt 21 to a back-and-forth motor 20 with a pulley 19 fixed to one end thereof.
When rotated, the support stand 17 can be moved back and forth by a mechanism built into the block 17a. On the other hand, the support stand 17 has guide rods 22 erected up and down, and supports a movable stand 23 formed in a substantially L-shape in a vertically movable manner.

A sliding table 24 movable in a direction perpendicular to the front-rear direction (hereinafter referred to as the left-right direction) is placed on the horizontal part of the movable table 23, and the sliding table 24 on the movable table 23 is mounted by means of left-right adjustment bolts 25. You can adjust the left and right positions. A vertical vibrating table 26 for supporting a fork is supported on the sliding table 24, and the vertical vibrating table 26 can be vibrated by rotating an eccentric cam 27 provided under the sliding table 24 with a motor 28. A fork holder 29 is mounted on the vertical vibration table 26 with bolts 30.
Attach the fork 3 on this pedestal 29.
1 is fixed by two belts 29a. The fork 31 is made of a cylindrical member made of quartz, and its base 32a is placed on the fork holder 29, and the belt 29a is wrapped around it to fix it.
A mounting portion 33b is formed by cutting off approximately 1/3 of the upper side of the tip in the length direction, and the wafer jig 12 can be mounted on this mounting portion 33.

According to this soft landing device, when a wafer or the like is placed on the mounting portion 33 of the fork 31 and the motor 20 is operated, the support stand 17 moves forward along the guide rail 16, and the fork 31 is moved into the furnace tube. Enter into 11. At this time, if the fork 31 is deformed downward toward the tip side due to mounting a wafer or the like, the motor 28 is activated to swing the vertical swing table 26 upward, and the fork mounting section 33 and Wafers etc. can be kept in a horizontal state. After the fork 31 has entered the furnace tube 11, wafers, etc. can be placed in the furnace tube 11 by slightly moving the movable table 23 downward along the guide rod 22. It is free to withdraw from the inner tube 11 or to wait near the opening of the inner tube. Also,
After the heat treatment is completed, the wafers and the like placed in this manner can be taken out of the furnace tube by the fork operation in the opposite manner to that described above.

Therefore, when correcting the straightness of the fork 31, as shown in FIG. Reference jigs 35 and 36 are installed, and a movable jig 37 is placed outside of these reference jigs 35 and 36. These reference jigs 35 and 36 and the movable jig 37
As shown in Fig. 4, rolling wheels 39 are attached to the four corners of the lower part of the barrier wall 38, and a weight 4 is attached to the center of the lower part.
0 is set. When these jigs are placed in the fork 31, their posture can always be oriented vertically by the action of the weight 40 and the rolling wheels 39, and at this time, the through hole 41 formed in the barrier wall 38 It is configured so that it coincides with the central axis of Further, a laser oscillator 42 is disposed on the support base 34 on the side of the base 32 of the fork, so that the emitted laser beam can be set at the central axis position of the fork.

Therefore, after placing the reference jigs 35 and 36 in the fork, the laser beam is applied to these reference jigs 35 and 36.
If the laser oscillator is set to pass through the 36 through holes 41, 41, respectively, this laser beam will be defined as the central axis of the fork. Since this laser light can be confirmed with the naked eye, the repair operator can recognize the bending of the fork simply by moving the movable jig 37 in the axial direction within the fork 31. In other words, the laser beam is transmitted to the through hole 41 of the movable jig 37.
There is no bend at the point where the laser beam passes, but when the laser beam hits the barrier wall 38, a bend occurs at that point. This allows the operator to move the movable jig 37
While moving the fork to check the state of the laser beam (how well it passes through the hole), you can soften the fork by applying a flame to the bent part of the fork, for example, and then straighten it. Straightness can be corrected.

As a result, it is possible to correct the straightness of the fork while checking the straightness of the fork with the naked eye, and it is possible to make good corrections with high efficiency without requiring much intuition or skill on the part of the operator. can.

Here, the through holes 41 formed in the reference jigs 35 and 36 and the movable jig 37 do not need to be aligned with the center position of the fork, and may be any hole. Also,
In this case, the reference jig may have a different configuration from that of the movable jig, for example by omitting the rolling wheels of the reference jig.

As described above, according to the fork straightness correction method of the present invention, the position of the laser beam is determined based on jigs placed at two points on the fork, and then the laser beam is moved within the fork using this laser beam as a reference. Since the fork is corrected while checking its bending condition using a movable jig, the operator can very easily correct the fork without requiring any intuition or skill.This improves correction efficiency. This has the effect that it is possible to improve the image quality and make good corrections.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the fork, FIG. 2 is a perspective view of the soft landing device, FIG. 3 is a perspective view illustrating a correction method, and FIG. 4 is a front view of the jig. 10... Soft landing device, 11... Furnace tube, 13... Wafer, 17... Support stand, 23
...Movable table, 24...Sliding table, 26...Vertical vibration table, 27...Eccentric cam, 31...Fork, 33
...Mounting section, 35, 36...Reference jig, 37...
Movable jig, 38... partition wall, 41... through hole.

Claims (1)

[Claims] 1. When correcting the straightness of a fork in a soft landing device that has a fork made by cutting a part of a cylindrical member such as quartz, the position of the laser beam is adjusted with reference to jigs placed at two points on the fork. This method for correcting the straightness of a fork in a soft landing device is characterized in that the straightness of the fork is corrected while determining the bending of the fork using a movable jig that can be moved within the fork based on the laser beam as a reference.