JP2002110577A - Vertical reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical reactor having furnace tubes disposed in the vertical direction, capable of accurately instructing a boat the position of a transfer unit for transferring works stacked in a plurality of stages in the vertical direction to the boat for treating the works in the reactor. SOLUTION: The reactor comprises support posts 24 for horizontally holding a plurality of stages of wafers W stacked in the vertical direction of furnace tubes and each post 24 composed of a hold face 40a for holding a part of the downside of the wafer W, a non-holding face 40b and an opposite face 40c has holding grooves 40 arranged in a plurality of stages along the vertical side of the post 24. At least one of the grooves 40 is a position teaching groove 50 which is disposed at a different position from the opposite faces 40c of other grooves 40 and has an opposite face 50c as a reference plane for teaching a transfer means position data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical oxidation furnace, a vertical heat diffusion furnace, and a vertical vacuum CVD (Chemical Vapor Deposition) furnace for forming a thin film on a semiconductor wafer. ) Relates to a vertical reactor equipped with a reaction tube.

[0002]

2. Description of the Related Art A variety of semiconductor processing equipment has often adopted a so-called batch processing method for processing a plurality of semiconductor wafers at once from the viewpoint of processing efficiency of semiconductor wafers. Accordingly, a single wafer processing method for processing semiconductor wafers one by one has been shifted. On the other hand, in a reaction furnace in which a semiconductor wafer is accommodated and processed in a reaction tube such as an oxidation furnace, a thermal diffusion furnace, and a low-pressure CVD furnace,
The batch processing system will have an advantage in the future in comparison with the single wafer processing system in terms of processing capacity, quality stability, cost, and the like. In the above-described reaction furnaces having reaction tubes such as an oxidation furnace, a thermal diffusion furnace, and a reduced pressure CVD furnace, a vertical reaction furnace in which the reaction tubes are arranged in a vertical direction (vertical direction) and a reaction tube in a horizontal direction (horizontal direction) are arranged. Although a horizontal reactor is used, a vertical reactor is mainly used because generation of particles can be suppressed and an arrangement area can be reduced.

[0003] In this vertical reactor, a plurality of semiconductor wafers are held, and a semiconductor wafer is transferred between a boat that is inserted into and pulled out of a reaction tube and a cassette that stores the semiconductor wafers. A device equipped with a mounting device is known. The above-mentioned boat is provided with a plurality of support pillars erecting on the base, for example, made of quartz,
A plurality of grooves for holding the semiconductor wafer horizontally are formed in the support columns. The transfer of the semiconductor wafers to the boat by the transfer device is performed based on the position data of the boat taught by the transfer device in advance. In order to teach the position data of the boat, the operator, for example, performs an operation of inputting an operation command to the transfer device from an external operation device such as a teaching controller, and causes the operator to actually perform the transfer operation of the semiconductor wafer. Confirms visually whether the semiconductor wafer is placed at an appropriate position with respect to the groove formed in the support column of the boat, and teaches the position at this time to the transfer device. At this time, the groove formed in the support column of the boat is configured by a holding surface for holding the semiconductor wafer, a surface located above the holding surface, and an opposing surface located on the outer periphery of the semiconductor wafer. The operator teaches the transfer device the position data of the boat so that the gap (clearance) between the facing surface and the outer peripheral edge of the semiconductor wafer has a predetermined size. Once the position data is taught to the transfer device, the transfer device repeatedly transfers the semiconductor wafer based on the taught position data of the boat. In addition, the work of teaching the position data of the boat to the transfer device is:
In a vertical reactor, maintenance is usually performed periodically, so that it is necessary for each maintenance. This is because when maintenance is performed, components such as the boat are removed from the device or disassembled, and the relative position between the boat and the transfer device may change before and after maintenance. .

[0004]

However, since the operation of teaching the position data of the boat to the transfer device is performed by the operator while visually confirming the appropriate position as described above, accurate teaching is required. The work requires skill, and the taught position data fluctuates for each teaching work, the clearance between the opposing surface of the groove and the outer peripheral edge of the semiconductor wafer varies, or the opposing surface of the groove and the outer peripheral edge of the semiconductor wafer are different. There was a possibility of contact. If the taught position data is not appropriate, the contact between the support pillar and the semiconductor wafer will cause
There is a possibility that the semiconductor wafer may be chipped or particles may be generated. Further, if the taught position data is not appropriate, the semiconductor wafer may fall from the groove of the support column. If the semiconductor wafer is damaged by dropping, there is a possibility that the yield will be reduced due to the adhesion of particles to other semiconductor wafers present in the reaction furnace, and the equipment operation rate will be reduced due to the need for equipment maintenance.
Furthermore, if the semiconductor wafer is not at a substantially constant position with respect to the groove of the support column, the radiant heat of the reaction furnace received by the semiconductor wafer and the heat distribution from the support column change, so that various types of films formed on the semiconductor wafer are changed. Thickness can vary.
As described above, in the related art, since the operation of transferring the semiconductor wafer to the boat has been performed by the operator, a margin for the clearance between the semiconductor wafer and the opposing surface of the groove of the boat cannot be guaranteed. Further, the relative position between the semiconductor wafer and the groove of the boat can be detected by a sensor, but there is a problem that the apparatus cost increases.

The present invention has been made in view of the above problems, and in a vertical reactor having a vertically arranged reaction tube, an object to be processed in the reactor is placed in a vertical (vertical) direction. The object of the present invention is to provide a vertical reactor capable of accurately teaching the position of the boat to the transfer device when transferring the boat to a boat which is held in a plurality of stages and held by the transfer device.

[0006]

The vertical reactor according to the present invention comprises:
A reaction tube arranged in a vertical direction, and a plurality of objects to be processed standing in a vertical direction on a base member arranged in a horizontal direction and being processed in the reaction tube are arranged in a plurality of stages in a vertical direction of the reaction tube. A support member that is provided with a support member that is held horizontally in an overlapping manner, and that is inserted into and pulled out of the reaction tube,
Transfer means for transferring the object to be processed to the boat according to the taught position data of the boat,
Each support member of the boat includes a holding surface that holds a part of the lower surface of the object to be processed, a non-holding surface above the holding surface, and the object between the holding surface and the non-holding surface. The holding member is configured with a facing surface facing the outer peripheral edge of the processing body, and includes holding grooves arranged in a plurality of stages along the longitudinal direction of the supporting member, and at least one of the plurality of holding grooves is another. Arranged at a position different from the facing surface of the holding groove portion, and
A position teaching groove having an opposing surface serving as a reference surface when teaching the position data to the transfer means.

[0007] The opposing surface serving as the reference surface is disposed at a position close to the other opposing surface of the same support member by a predetermined distance from the outer peripheral edge of the object to be processed.

The transfer means transfers the workpiece to the holding groove of the boat based on the position data of the boat taught by the position teaching groove.

The position teaching groove is located at the lowermost part of the support member.

The object to be processed has a disk shape, and the surface facing the position teaching groove is a curved surface having a curvature along the outer peripheral edge of the object to be processed.

In the present invention, the object to be processed is transferred to the position teaching groove of the boat by the transfer means, and the object to be processed is positioned at a predetermined position with respect to the opposing surface serving as the reference surface of the position teaching groove. Thereby, the position data of the boat is taught to the transfer means. The object to be processed is transferred to another holding groove based on the taught position data of the boat. When the opposing surface of the position teaching groove is located at a position close to the opposing surface of the other holding groove by a predetermined distance from the outer peripheral edge of the object to be processed, the object is placed on the opposing surface of the other holding groove. At the time of positioning, the predetermined distance serves as a margin, and contact between the support member and the object to be processed is suppressed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an oxidation / diffusion furnace as one embodiment of a vertical reaction furnace of the present invention. In FIG. 1, the oxidation / diffusion furnace 1 includes a cassette storage unit 2, a cassette transfer unit 3, a wafer transfer unit 4, a reaction tube 7, and a boat unit 21.

In FIG. 1, the cassette storage section 2
The cassette C is provided on the upper side of the diffusion furnace 1 and houses a plurality of wafers such as disk-shaped silicon and quartz as objects to be processed in the oxidation / diffusion furnace 1.

The cassette transport section 3 transports a cassette C containing wafers to be processed from among the cassettes C stored in the cassette storage section 2 to the wafer transfer section 4.

The reaction tube 7 internally performs processing for forming a thin film on a wafer. The reaction tube 7 is formed of, for example, a high-purity quartz tube, and is arranged along the vertical direction. The lower end of the reaction tube 7 is open, and the wafer held by the boat 21 is accommodated in the reaction tube 7 through the opening.

The wafer transfer unit 4 collectively transfers the wafers stored in the cassette C transferred by the cassette transfer unit 3 to the boat unit 21. The transfer of wafers to the boat unit 21 by the wafer transfer unit 4 is performed by previously teaching the position of the boat unit 21 to a controller (not shown) of the wafer transfer unit 4 and based on the taught position data of the boat unit 21. Do it. In order to teach the position data of the boat unit 21 to the controller of the wafer transfer unit 4, an operation command is input to the wafer transfer unit 4 from an external operation device such as a teaching pendant, and the wafer transfer of the wafer is actually performed. The loading section 4 is performed, and the operator
It is visually confirmed whether the wafer is placed at an appropriate position with respect to the boat unit 21 and the position at this time is instructed to the wafer transfer unit 4.

FIG. 2 is a view showing a schematic configuration of the boat section 21. As shown in FIG. In FIG. 2, the boat 21 is disposed below the reaction tube 7. The boat 21 includes a boat 23, a support 33 supporting the boat 23, and a cap member provided below the support 33. 32, a flange portion 31 for holding the lower surface of the cap member 32, and a lifting device 30 for raising and lowering the flange portion 31 in the vertical direction.

The boat 23 horizontally holds the wafers W in a plurality of stages in the longitudinal direction of the reaction tube 7. The detailed structure of the boat 23 will be described later.

The elevating device 30 raises the flange portion 31 to simultaneously raise the boat 23, the support 33 and the cap member 32, and inserts the boat 23 into the reaction tube 7. Further, the cap member 32 is
, The opening 7a of the reaction tube 7 is sealed.

When the reaction tube 7 is sealed by the cap member 32, a reaction gas is introduced from a gas introduction portion provided at a predetermined position of the reaction tube 7, and a predetermined process is performed on the wafer W. When the processing of the wafer W is completed, the reaction tube 7
The reaction gas is discharged out of the reaction tube 7 from a gas exhaust unit provided at a predetermined location of the reaction tube.

FIG. 3 is a side view showing the structure of the boat 23, and FIG. 4 is a sectional view taken along the line AA of FIG. As shown in FIG. 3, the boat 23 includes a base member 25 supported by the support 33, a plurality of support columns 24 erected on the base member 25, and upper ends of the plurality of support columns 24. And a connecting plate 26 for connecting the parts.

As shown in FIG. 4, four support columns 24 are provided, and the support columns 24 are arranged at positions where they do not interfere with the wafers W transferred from the cassette C in the direction of arrow D by the wafer transfer section 4. Have been. The support columns 24 are formed of a material such as SiC (quartz), for example. In addition,
In the present embodiment, the number of the support columns 24 is set to four.
It can be configured as a book.

Each support column 24 has an arrow D
A holding groove 40 for holding a part of the lower surface of the wafer W transferred in the direction is formed. The holding grooves 40 are arranged in a plurality of stages in the longitudinal direction of each support column 24. That is, the four support columns 24 are provided with the holding grooves 40 at positions corresponding to each other, and the wafer W is held by the corresponding four holding grooves 40.
Hold.

FIG. 5 is a vertical partial sectional view of the support column 24. As shown in FIG. As shown in FIG. 5, the holding groove 40 includes a holding surface 40a for holding the lower surface of the wafer W, and a holding surface 40a.
a non-holding surface 40b above the upper surface a, and a facing surface 40c between the holding surface 40a and the non-holding surface 40b and facing the outer peripheral edge of the wafer W. The holding surface 40a and the non-holding surface 40b are formed by planes parallel to the surface of the wafer W, and the facing surface 40c is orthogonal to the holding surface 40a and the non-holding surface 40b, and the outer peripheral edge of the wafer W Is constituted by a curved surface having a curvature along.

The distance between the holding surface 40a and the non-holding surface 40b of the holding groove 40 is set to a distance larger than the thickness of the wafer W, for example, about 4 to 10 mm. The depth L ₀ of the holding groove 40, that is, the distance from the opening-side end of the holding groove 40 to the facing 40 c is, for example, about several mm. Holding groove 4 having such a structure
When the lower surface of the wafer W is held at 0, from the viewpoints of quality assurance of the thin film formed on the wafer W, prevention of the falling of the wafer W from the holding groove 40, prevention of breakage of the wafer W, and the like,
It is desirable to secure a certain clearance CL1 between the wafer W and the facing surface 40c.

On the other hand, in the support column 24 of the boat 23 according to the present embodiment, at least one of the holding grooves 40 is a position teaching groove 50. As shown in FIG. 5, the position teaching groove 50 includes a holding surface 50a for holding the lower surface of the wafer W, a non-holding surface 50b above the holding surface 50a, a holding surface 50a and the non-holding surface 50b.
And an opposing surface 5 facing the outer peripheral edge of the wafer W
0c. The distance between the holding surface 50a and the non-holding surface 50b of the position teaching groove 50 is set to the same value as the distance between the holding surface 40a and the non-holding surface 40b of the holding groove 40 described above.

The facing surface 50c of the position teaching groove 50 is formed of a curved surface which is perpendicular to the holding surface 50a and the non-holding surface 50b and has a curvature along the outer peripheral edge of the wafer W. Further, the opposing surface 50c is arranged at a position different from the opposing surface 40c of the holding groove 40, and a predetermined distance L is provided between the opposing surface 40c and the outer peripheral edge of the wafer W.
Are located only in close proximity. That is, the facing surface 50c is disposed closer to the center of the wafer W than the facing surface 40c. The facing surface 50c serves as a reference surface when teaching the position of the boat 23 on which the wafer W is to be transferred to the controller of the wafer transfer unit 4 described above. That is, based on the position of the facing surface 50c, the boat unit 2
The position 1 is taught to the controller of the wafer transfer unit 4.

The above-described position teaching groove 50 is provided in the support column 24.
Is preferably provided at the lowermost part. Normally, a dummy wafer W is set at the lowermost portion of the support column 24. The position of the facing surface 50c is different from that of the other facing surface 40c.
c, the gas flow of the reactant gas near the opposing surface 50c may be different from the state of the gas flow of the reactant gas near the other opposing surface 40c, and the uniformity of the thin film formed on the wafer W Because it may affect the Further, the position teaching grooves 50 are provided on all of the four support columns 24.

Next, an example of the teaching operation of the position data for transferring the wafer W to the boat 23 having the above configuration will be described. First, the operator operates the external operation device, grips the wafer W stored in the cassette C by the wafer transfer unit 4, and moves the wafer W toward the position teaching groove 50 provided on the boat 23. While visually checking the wafer W approaching the position teaching groove 50, the operator forms a predetermined clearance CL2 between the outer peripheral edge of the wafer W and the facing surface 50c as shown in FIG. The wafer W is moved to the position. When the operator confirms that a predetermined clearance CL2 has been formed between the outer peripheral edge of the wafer W and the facing surface 50c, the operator determines the position at this position and sends the position to the controller of the wafer transfer unit 4 from the external operation device. Teach.

By the operation of the operator, the teaching of the position data of the boat 23 to the controller of the wafer transfer section 4 is completed.

The wafer transfer unit 4 to which the position data of the boat 23 is taught performs the transfer operation of the wafer W based on the taught position data. Specifically, first, the cassette C holding the wafers W stored in the cassette storage unit 2 is transferred to the wafer transfer unit 4 by the cassette transfer unit 3.

The wafer transfer section 4 collectively transfers the wafers W held in the cassette C to the boat 23 based on the taught position data. Support column 24 of boat 23
The wafers W are collectively transferred to the position teaching groove 50 located at the lowermost position and the holding grooves 40 in a plurality of stages above the position teaching groove 50, and the wafers W are stacked in a plurality of stages.

At this time, as shown in FIG. 5, the facing surface 50c of the position teaching groove 50 and the facing surface 4c of the holding groove 40 are formed.
0c, there is a distance L, so that the clearance CL1 between the outer peripheral edge of the wafer W and the facing surface 40c is guaranteed to be at least larger than the distance L. In other words, even if there is some variation in the position data taught with reference to the opposing surface 50c of the position teaching groove 50, the outer peripheral edge of the wafer W and the opposing surface 40c are not affected.
The clearance CL1 between the first and second members c is secured at least by the distance L.

As described above, according to the present embodiment, the position of the boat 23 is instructed to the wafer transfer unit 4 with reference to the facing surface 50c of the position teaching groove 50, so that the outer peripheral edge of the wafer W is opposed. Clearance C between surface 40c
Problems such as a large variation in L1 and a contact between the outer peripheral edge of the wafer W and the facing surface 40c can be prevented. As a result, the wafer W is positioned at a stable position with respect to the holding groove 40, and the quality of the film formed on the wafer W can be stabilized. Further, generation of particles due to breakage of the wafer W can be prevented, and a decrease in yield and apparatus operation rate can be prevented.

The present invention is not limited to the above embodiment. In the embodiment described above, the support column 2 of the boat 23 is used.
Although the position teaching groove portion 50 is provided at the lowermost portion holding the dummy wafer of No. 4, the configuration may be provided at a plurality of locations such as the lowermost portion, the intermediate portion, and the uppermost portion of the support column 24. In this case, the lowermost part, the middle part,
A groove 50 for position teaching is provided at the top, and the wafer W
Is taught the position of the boat 23 to which is to be transferred. When the position of the boat 23 at the plurality of positions is different, the controller of the wafer transfer unit 4 calculates a tilt due to a processing error and an assembling error of the support column 24 from the position data. It is also possible to adopt a configuration in which the taught position data is corrected according to the inclination. Thereby, contact between the wafer W and the support column 24 due to the tilt of the support column 24 can be prevented.

[0036]

According to the present invention, in a vertical reactor having a vertically arranged reaction tube, an object to be processed in the reactor is held in a plurality of stages in the vertical direction (vertical direction). When the transfer is performed by the transfer means on the boat, the position of the boat can be accurately taught to the transfer means.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an oxidation / diffusion furnace as one embodiment of a vertical reaction furnace of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a boat unit 21.

FIG. 3 is a side view showing the structure of the boat 23.

FIG. 4 is a sectional view taken along the line AA of FIG. 3;

FIG. 5 is a vertical partial sectional view of a support column 24.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 oxidation / diffusion furnace, 2 cassette storage unit, 3 cassette transfer unit, 4 wafer transfer unit, 7 reaction tube, 21 boat unit, 23 boat, 24 support column, 40 holding groove unit , 40a: holding surface, 40b: non-holding surface, 40c: facing surface, 50: groove for position teaching, 50a: holding surface, 50b ...
Non-holding surface, 50c: facing surface, W: wafer.

Claims (5)

[Claims] 1. A reaction tube arranged in a vertical direction, and an object to be processed standing in a vertical direction on a horizontally arranged base member and processed in the reaction tube, A support member for vertically holding a plurality of stages and holding horizontally, a boat inserted and withdrawn into and from the reaction tube, and the object to be processed on the boat according to the taught position data of the boat. Transfer means for transferring, each supporting member of the boat, a holding surface holding a part of the lower surface of the object, a non-holding surface above the holding surface, the holding member And a holding groove formed in a plurality of stages along the longitudinal direction of the supporting member, the holding member being constituted by a facing surface facing the outer peripheral edge of the object to be processed between the surface and the non-holding surface. At least one of the holding grooves of the other holding groove A vertical reactor having a position teaching groove disposed at a different position from the facing surface of the groove and having a facing surface serving as a reference surface when teaching position data to the transfer means. 2. The apparatus according to claim 1, wherein the opposing surface serving as the reference surface is disposed at a position close to an outer peripheral edge of the object by a predetermined distance from another opposing surface of the same support member. The vertical reactor as described. 3. The transfer unit according to claim 2, wherein the transfer unit transfers the workpiece to the holding groove of the boat based on the position data of the boat taught by the position teaching groove. Vertical reactor. 4. The vertical reactor according to claim 3, wherein said position teaching groove is located at a lowermost portion of said support member. 5. The vertical object according to claim 1, wherein the object to be processed has a disk shape, and a surface facing the position teaching groove is a curved surface having a curvature along an outer peripheral edge of the object to be processed. Type reactor.