JPS63265444A - Diffusion method - Google Patents

Abstract

PURPOSE:To enable the uniform diffusion processing of many semiconductor wafers, by transferring all wafers, which are housed in a wafer receiver and provided with orientation flat alignment, to a port for diffusion furnace use while their aligning states are maintained and next by inserting the port for diffusion furnace use into the diffusion furnace so as to perform a diffusion process. CONSTITUTION:Every e.g., twenty five wafers 2, for which a pre-process e.g., a washing process is finished, are housed at predetermined intervals in a wafer receiver 1 and they are carried. The wafer receiver 1 is mounted on an orientation flat aligner's table 7 for wafer receiver 1 mounting use. In succession the table 7 is moved to dispose the wafer receiver 1 above the aliner. Two rollers 3, 3 for orientation flat alignment are moved upwards and many wafers 2 are simultaneously mounted on these rollers 3, 3 and then the rollers 3, 3 are fixed. Orientation flat alignment processes for many wafers 2 are simultaneously performed by rotation means of these rollers 3, 3. After orientation flat alignment processes are performed for all the wafers 2, these orientation flat aligned wafers 2 are transferred to a port for diffusion furnace use. The port in which wafer lines are housed by this transfer process is inserted into the diffusion furnace, and then a diffusion process is performed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a diffusion method in the manufacturing process of semiconductor wafers (hereinafter referred to as wafers).

[Conventional technology]

When manufacturing wafers, in the process of transporting the wafers received from the cleaning equipment to the diffusion furnace side, they are transferred from the wafer storage container to a board dedicated to the diffusion furnace, inserted into the diffusion furnace, and placed in the cylindrical container of the diffusion furnace. There is a process in which gas is jetted from the center of the wafer to uniformly adhere the gas to the surface of each wafer.

[Problems to be solved by the invention]

In this process, the center of the cylindrical container (hereinafter referred to as tube) of the diffusion furnace and the center of the wafer inserted into the tube are arranged such that the center of the wafer is located above the center of the tube due to the structure of the boat. It has a positional relationship of being located at In this case, the center of the wafer is eccentrically located above the center of the tube, and when a group of wafers is inserted along the center axis of the tube, a gap occurs between the tube and the wafer when viewed from the entrance side of the tube. The gap is narrower at the top and wider at the bottom. Therefore, the gas flow tends to flow downward with less resistance, and the gas is not evenly attached to the surface of each wafer.Furthermore, the orientation flat of the semiconductor wafer is aligned with a certain crystal axis, and the semiconductor wafer The reaction in the manufacturing process is also greatly affected by the direction of the crystal axis. The present invention has been made in response to the above-mentioned problems, and provides a diffusion method that allows a large number of semiconductor wafers to be uniformly diffused in a diffusion furnace at the same time. [Structure of the invention]

[Means to solve the problem]

A process of installing a wafer storage container in which a plurality of semiconductor wafers are housed at predetermined intervals on an orientation flat aligner, and two rollers of this orientation flat aligner to align all wafers provided in the wafer storage container. At the same time, all the semiconductor wafers are supported, and in this supported state, all the semiconductor wafers are rotated by the rollers to align the orientation flats, and all the semiconductor wafers with the orientation flats aligned are placed in the wafer storage container, and the orientation flats in the wafer storage container are aligned. a step of transferring all the wafers to a diffusion furnace boat while maintaining their aligned state; a step of inserting the above-mentioned diffusion furnace boat into the diffusion furnace after the transfer is completed; and a step of aligning the orientation flat to the above-mentioned diffusion furnace boat. The diffusion method is characterized by a step of performing a diffusion treatment on a wafer.

【Example】

An embodiment of the method of the present invention will be described below based on the drawings. The wafer 2 that has completed the previous process, for example, the cleaning process, has, for example, 25
The wafers are stored one by one in a wafer storage device at predetermined intervals and transported. The transported wafer storage container is set in an orientation flat aligner device for semiconductor wafers 2. This set state is shown in FIG. That is, the wafer storage device 1 is placed on the wafer storage device 1 mounting table 7 of the orientation flat aligner. After this placement, the placement table 7 is moved to a predetermined position of the orientation flat alignment portion by rotating the ball screw 11. This movement positions the wafer storage container 1 above the aligner. After the wafer storage device 1 is installed in this way, the two rollers 3.3 for aligning the orientation flat are moved upward, and the rollers are placed at a position where a large number of wafers 2 are placed on these rollers 3, 3 at the same time. 3. Fix 3. By rotating these rollers 3, 3, a process of aligning a large number of wafers 2 to an orientation flat is performed simultaneously by the means described below. After aligning the orientation flats of all the wafers 2, these wafers 2 with their orientation flats aligned are transferred to a boat for a diffusion furnace, and the boat containing the row of wafers is inserted into the diffusion furnace to perform a diffusion process. At this time, the wafer row is subjected to a diffusion process in a state in which the orientation flats of all the wafers are aligned in a diffusion furnace. Next, the above orientation flat alignment device will be explained. ■; A rotating device that rotates the wafer 2 stored in the wafer storage container L; ■; A stopper 6 that rotates the orientation flat portion of the rotating wafer 2;
and (2) a holding device for mounting the wafer storage container 1 on the carrier liner 7 and fixing it on the holding table 5. The rotating device described in (2) above will be described in detail. Two parallel rollers 3 are mounted horizontally on a mounting base 9 and held rotatably, and a belt 4 or the like is stretched between the drive unit 8 installed on the mounting base 9, and the drive unit 8 drives the rollers 3. Rotate. By providing the two rollers 3 as described above, the orientation flat portion of the wafer 2 is aligned with the roller 3 of the first grain.
Even when the wafer 2 reaches the wafer 2, the rotation of the wafer 2 does not stop because the other roller 3 is in contact with two sides of the sea urchin that is not the orientation flat part.In other words, the wafer 2 is always rotated. There is. The above mounting stand 9 is the base 12
It is arranged on the lifting device 10 fixed to the lifting device 1.
0 is activated, the entire rotating device moves up and down, and the rollers 3 can freely push up the wafers 2 in the wafer container 1 to a predetermined height. Next, we will discuss the stopper device (3) that blocks the orientation flat portion of the wafer 2 with the stopper 6. This device consists of a stopper 6 and a lifting device (not shown), and the stopper 6 is attached to the tip of the lifting device. The mechanism is such that it can be raised and lowered in the vertical direction. This stopper 6 is connected to each roller 3 of the rotating device.
The rollers are arranged parallel to each other in the middle of the rollers in parallel to the axial direction of the rollers. The wafer 2 being rotated by the two rollers 3 stops rotating when the orientation flat portion hits the stopper 6. Furthermore, referring to the holding device (2) above, it consists of a carrier liner 7 on which the wafer storage container 1 is placed and a holding table 5, and the wafer storage device 1 is placed on the carrier liner 7 and fixed by the holding table 5, so that it is integrated. ing. The carrier liner 7 has an opening at the center to expose the bottom surface of the wafer storage container 1, and is similarly opened so that the lower surface of the wafer 2 is exposed from the bottom surface of the wafer storage container 1. To describe the relationship between the parts (1) to (2) above, the stopper device is mounted on the mounting base 9 of the rotating device, and the wafer storage container 1 is supported by the carrier liner 7 directly above the rotating device. Next, the orientation flat alignment process will be explained. The structures of the rotation device, stopper device, and wafer 2 holding device of the orientation flat aligner are as described above, and the operation of each part will be explained using FIGS. 2 to 6. 2 to 6 are simplified side sectional views and explain the operation of each part. As shown in FIG. 6, when the wafer holder 1 is placed on the upper surface of the carrier liner 7 of the holding device, the wafer 2 is held with the outer periphery of the wafer 2 in contact with the shoulder A of the wafer holder 1. In order to start aligning the orientation flat portions of each wafer 2 from this position, the rotating device is raised to a predetermined position as shown in FIG. Then, the stopper 6 is also raised. This raising is performed by both the lifting device 10 of the rotating device and the lifting device (not shown) of the stopper device. As shown in FIG. 3, when the two rollers 3 rotate and the wafer 2 begins to rotate, the orientation flat portion of the wafer 2 collides with the stopper 6 to restrict the rotation of the wafer 2, and the wafer 2 It will be in a stopped state. As shown in FIG. 4, when all the wafers 2 are aligned in a certain direction, the stopper 6 is lowered to a predetermined position. Further, as shown in FIG. 5, the rotation of the roller 3 is set so as to align the orientation flat portions at required positions. When the orientation flat portions are aligned at the required positions, the rotation of the roller 3 is stopped, and the rotating device is lowered to a predetermined position in order to separate the wafer 2 from the rotating device as shown in FIG. In order to move the wafer storage container 1 with the orientation flat portion aligned at the required position in this way to another location, the carrier liner 7 can be transported by rotation of the ball screw 11 as shown in FIG. . It is also possible to remove the wafer storage container l with the orientation flat portion aligned at a predetermined position at a location indicated by the two-dot chain line.

【Effect of the invention】

In this way, the orientation flat portions of the wafers 2 in the wafer container 1 can be aligned at designated positions. Therefore, when the wafer 1 is inserted into the tube and the 2 groups of wafers placed regularly on the boat of the tube are inserted along the central axis direction of the tube, a wafer 2 is generated between the tube and the wafer 2 when viewed from the entrance side of the tube. The orientation flat group can be set freely based on the condition of the gap. Wafers 2 of consistently stable quality can be obtained by eliminating the "unevenness" of the gas jet that occurs when the gas is jetted. Furthermore, since the crystal axes of all wafers in the diffusion furnace are aligned, uniform diffusion processing can be performed on each wafer. Another effect is that when the orientation flat portions are aligned, if the orientation flat portions are present on the upper surface of the wafer storage container l, the alignment of the orientation flat portions can be visually confirmed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an orientation flat aligner for explaining an embodiment of the method of the present invention, and FIGS.
The figures up to this figure illustrate the operation of the apparatus shown in FIG. 1, and are side sectional views of the main parts of FIG. l...Wafer storage section 2...Wafer 3...Roller 4...Belt 5...Holding stand
6...Stopper 7-・Carrier liner 8・
... Drive unit 9 ... Mounting base 10 ... Lifting device 11 ... Ball screw 12 ... Base Patent applicant Tokyo Electron Ltd. TS4 cause

Claims (1)

[Claims] 1. The step of installing a wafer storage container in which a plurality of semiconductor wafers are housed at predetermined intervals on an orientation flat aligner, and the two rollers of this orientation flat aligner aligning the entire wafer storage container with A step of simultaneously supporting the wafers, rotating all the semiconductor wafers with the rollers in this supported state to align the orientation flats, and placing all the semiconductor wafers with the orientation flats aligned on the wafer storage device, and aligning the orientation flats in the wafer storage device. a step of transferring all the combined wafers to a diffusion furnace boat while maintaining an aligned state, and a step of inserting the diffusion furnace boat into the diffusion furnace after the transfer is completed;
A diffusion method comprising the step of performing a diffusion treatment on wafers housed in the diffusion furnace boat.