JPH02129505A - Automatic aligning and setting device and automatic cylindrical grinder for ingot - Google Patents

Abstract

PURPOSE:To accurately set the ingot on an aligning and cylindrical grinder with efficiency by measuring the sectional shape of the ingot at axial positions and calculating the center of grinding. CONSTITUTION:The ingot W to be aligned is mounted horizontally on claws fitted to lower holders 18 of respective support parts 14 and a cylinder 19 is driven to clamp the ingot W between upper and lower holders 17 and 18. Then, a cylinder 10 is driven to move a moving table 7 and then both end surfaces of the ingot W are supported by the clamp shaft of a marking part 8. In this state, the ingot W is rotated to measure the sectional shape of the ingot W at the axial positions by indicators 5a-5c. A CPU 39 calculates the center of grinding from the measured sectional shape of the ingot W and drives the marking pen of a marking part 8 to mark the center of grinding in both end surfaces of the ingot W.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic centering/setting device and an automatic cylindrical polishing device used in a cylindrical polishing process of single crystal ingots in semiconductor manufacturing.

(Prior art) Semiconductor wafers are obtained by thinly slicing a single crystal ingot pulled by the FZ method, C2 method, etc. in the direction perpendicular to the axis, but before slicing, the outer periphery of the ingot is polished by a cylindrical polishing disk. , formed into a cylindrical shape.

Incidentally, the ingot must be centered so that the maximum diameter can be obtained after cylindrical polishing, and various centering methods regarding this point have already been proposed (for example, Japanese Patent Laid-Open No. 57-66909, Japanese Patent Publication No. 60-1768
No. 2, see Publication No. 61-33446).

(Invention or Problem to be Solved) However, there is no specific apparatus for carrying out such a centering method, particularly a centering method applied to cylindrical polishing of single crystal ingots in the semiconductor manufacturing field. The reality is that no proposal regarding a specific device for this purpose has been made yet.

The present invention has been made in view of the above circumstances, and its purpose is to accurately and efficiently center an ingot and set the ingot on a cylindrical polishing machine without relying on the skill and intuition of the operator. An object of the present invention is to provide an automatic ingot centering and setting device and an automatic cylindrical polishing device that can perform the following operations.

(Means for solving the ff problem) In order to achieve the above object, the present invention includes a support part that supports an ingot, and a measurement part that measures the cross-sectional shape of the ingot supported by the support part at a plurality of locations in the axial direction. , a calculation unit that calculates the polishing center based on the cross-sectional shape of the ingot measured by the measurement unit, and a marking unit that marks the polishing center calculated by the calculation unit on both end faces of the ingot. It is characterized by comprising an automatic centering device.

The present invention also provides a chuck section for chucking an ingot whose polishing center has been marked by the automatic centering device; a monitor section for monitoring the polishing center marked on the ingot chucked by the chuck section; an alignment unit that aligns the center of polishing monitored by the monitor unit with the center of rotation of the cylindrical polisher;

The present invention is characterized in that the ingot setting device is configured to include a conveying section that conveys the ingot after alignment to a cylindrical polishing machine.

Furthermore, the present invention is characterized in that an automatic cylindrical polishing device is configured including the automatic centering device, the setting device, and the cylindrical polishing disk.

(Function) According to the present invention, the polishing center of the ingot is analytically determined based on cross-sectional measurement data of the ingot, and the setting device aligns the polishing center with the center of rotation of the cylindrical polishing disc, thereby polishing the ingot. Since the ingot is set on a cylindrical polisher, centering and setting of the ingot can be performed accurately and efficiently without relying on the skill and intuition of the operator.

The known centering method can be specifically applied to the cylindrical polishing of single crystal ingots, in particular in the field of semiconductor production.

(Example) An example of the present invention will be described below based on the accompanying drawings.

First, the configuration of the automatic centering device will be explained based on FIGS. 1 to 4. That is, FIG. 1 is a front view of the automatic centering device l, FIG. 2 is a side view of the same, and FIG. 3 is a side view of the support part 14.
FIG. 4 is an enlarged cross-sectional view of the marking part 8 of the device 1, and in the left and right direction of FIG.
are erected, and a support bar 4 is installed horizontally between the upper parts of these columns 3.3. Three indicators 5a, 5b, and 5c are supported on this support bar 4 so that their positions can be adjusted freely.

Further, a fixed table 6 and a movable table 7 are provided in the left and right direction of FIG. 1, and marking portions 8°8, the details of which are shown in FIG. ing.

The movable table 7 is movable by a slider lO... which is slidably fitted into two guides 9.9 installed in the left-right direction of FIG. 1 (perpendicular to the paper surface of FIG. 2). A cylinder 11 is fixedly attached to this, and a rod lla extending from the cylinder 11 is connected to a joint 12.
It is connected to the fixing member 13 via.

Further, two supporting parts 14.14 are installed between the fixed table 6 and the movable table 7 on the base 2 so as to be movable along the guides 9.9. As shown in FIG. 3, each support part 14 has a fixed holder 16 installed on two shafts 15, is, and is disposed above and below the fixed holder 16, and is slidably inserted into the shaft 15.15. Top, holder 17
．． 18 and the cylinder 1 fixed to the fixed holder 16
A rod 19a extending downward from the cylinder 19 is connected to the lower holder 1 via a joint 20.
8 is connected.

In addition, the opposing parts of the upper and lower holders 17 and 18 are marked with ■
Block-shaped claws 17a and 18a are attached to each.

Here, the details of the marking part 8 will be explained based on FIG. 4. The fixing member 21 has a cylindrical clamp shaft 2.
2 is rotatably supported via a ball bearing 23 and an angular contact ball bearing 24, and a ring-shaped friction member 25 for gripping the ingot W is fixed to one end of the clamp shaft 22. A gear 26 is integrally formed on the outer periphery of the clamp shaft 22.

Further, a stepping motor 27 for rotating the ingot W is fixed on the upper part of the fixed member 21, and a gear 28 that meshes with the gear 26 is connected to the end of an output shaft 27a extending from the stepping motor 27. It is worn.

On the other hand, a holder 30 is movably supported by a slide guide 29 installed on the fixed member 21 in a direction perpendicular to the plane of the paper in FIG. It is inserted and supported so as to be movable in the left-right direction in FIG. 4, and the tip of the marking ben 31 faces the hollow portion of the clamp shaft 22. Further, a mark air cylinder 33 is fixed to the upper part of the holder 30, and a rod 33a extending from the cylinder 33 is connected to the end of the mark ben 31 via a connecting member 34. Incidentally, a shock absorbing spring 35 is wound around the end of the marking ben 31.

Furthermore, a ball screw shaft 36 which is long in the direction perpendicular to the plane of the paper in FIG.

By the way, as shown in Fig. 1, there is a CRT on the base 2.
Display 38. A CPU 39 and an operation panel 40 are installed.

Next, the centering operation by the single automatic centering device 221 will be explained.

First, the ingot W to be centered is placed horizontally on the claws 18a attached to the lower holder 18 of each support part 14,
If the cylinder 19 is driven to move the lower holder 18 upward, the ingot W will be moved to the upper and lower holders 17, 18 by the claws 17a,
It is held between 1 Ball.

Thereafter, if the cylinder 10 is driven to move the moving table 7 to the left along the LM guides 9, 9 in FIG.
Supported by 2.

In the above state, as the ingot W is rotated, the cross-sectional shape of the ingot W is actually measured, and the polishing center is calculated based on the measured data. The explanation will be based on the explanatory diagrams shown in a) to (d).

As described above, both ends of the ingot W are held together by both clamp shafts 22.
22, as shown in Figure 6(a).
two indicators 5a, 5b.

5c is brought into contact with the outer periphery of the ingot W, and the stepping motor 27 is driven to transfer its rotational power to the gears 28 and 26.
The ingot W is transmitted to the ingot W through the
Rotate each indicator 5a once in the direction of the arrow a),
Measure the cross-sectional shape of the ingot W at the contact point of 5b and 5c (step 5r2!l),
1iS654 (b) The cross-sectional shape of the ingot W (ltJ planes A, B, and C) at each measurement point as shown in D is obtained, and this cross-sectional shape is similar to the CRT display 3 shown in FIG.
8.

After that, the above 311raA, B, and C become the 6th [J (c
) as shown in FIG. 5 (step 2 in FIG. 5), and if the ingot W has a tilt due to the support of the clamp shafts 22, 22, this tilt is corrected (step 3 in FIG. 5).
), the minimum cross section is calculated by the CPU 39 shown in FIG. 1 (see step 4 in FIG. 5 and FIG. 6(c)).

Thereafter, the approximate center of the maximum circle inscribed in the minimum cross section (indicated by a solid line in FIG. 6(d)) is calculated by the known minimum cross section inscribed centripetal method (step 5 in FIG. 5), and this approximate center is calculated using the known minimum cross section inscribed centripetal method. Based on this, the detailed center is calculated using the same method (step 6) in FIG. 5, and the finally determined center is the polishing center 0.
becomes.

Above polishing center 0. Once obtained, the correction amounts ΔX and ΔY (see Fig. 6(d)) between this and the rotation center 0 are calculated,
These correction amounts (correction amounts on orthogonal coordinates) ΔX and ΔY are the values r on polar coordinates using the following equations.

is converted to θ (step 7 in the tlS5 diagram).

The correction amounts r and θ are obtained as described above, and the polishing center 01 is marked on both end faces of the ingot W by positioning both marking portions 8.8 at the pole seats all (r , θ) (the fifth At step 8°9) in the figure, a series of centering operations are completed (step 10 in figure tjS5), which is performed as follows.

That is, by driving the stepping motor 27, the ingot W
After rotating the ingot W by an angle of 0 from its current position,
Then, the stepping motor 37 is driven to rotate the ball screw shaft 36, and the holder 30 is moved along with the marking ben 31 by a distance r. Then, the tip of the marking ben 31 is at the polishing center 0. Therefore, if the mark air cylinder 33 is driven and the mark ben 31 is moved to the right in FIG. Plot.

In this way, the centering work of the ingot W can be performed accurately and efficiently without relying on the skill and intuition of the operator.

Incidentally, in the above embodiment, a mark marker was used to plot the polishing center O1, but a laser marker using a laser beam or the like may be used instead.

Next, the configuration of the setting device 50 according to the present invention will be explained based on FIGS. 7 and 8.

FIG. 7 is a front view of the setting device N50, and FIG. 8 is a side view of the same. Two guides 52, 52 are laid on the base 51 of the setting device 50 in the left and right direction in FIG. A chuck part 53 and an alignment part 54 are movably supported on the guides 52 and 52.

The chuck part 53 has two chuck hands 55.55.
Each chuck hand 55 has upper and lower fingers 56.
．． 57, and the lower finger 57 has a cylinder 58.
It can be moved up and down by.

Further, the alignment section 54 has adjustment sections 54a, 54b, 54c, and 54d that adjust the posture of the ingot W in the θ1.0□, Y, and X directions shown in FIG.

By the way, the automatic centering device mentioned above! The ingot W centered by ll is chucked and horizontally supported by the chuck part 53 as shown in the figure, or the ingot W
Reflection mirrors 59.59 are installed on the left and right sides of the
A) and (B) are installed, and the TV cameras (A) and (B) are monitors (A) and (B), which are receivers (see Figure 10).
It is connected to the. Furthermore, Figure 1O shows the set'! 5 is a schematic configuration diagram of a device 50. FIG.

In the state shown by the solid line in FIG. 7, the polishing center ol attached to both end faces of the ingot W.

The image of O1' passes through a reflecting mirror 59, 59 and is sent to a TV camera (
Images are captured at A) and (B), and these images are displayed on monitors (A) and (B).

Now, if the polishing center 0+, O+° before alignment is at the position shown in FIG. The ingot W is adjusted in the θ1 direction and its position moves as shown in FIG.
After adjustment in the Y direction, the positions of the polishing centers 0, , and Oro change as shown in FIG. It is placed at the center of rotation of the cylindrical grinder l1gq1160 shown in the figure.

When the alignment is completed as described above, the chuck part 53 and the alignment part 54 are moved to the left along the guides 52 and 52 as shown by the chain line in FIG. The ingot W is conveyed to the cylindrical polishing disc 60 and set therein with its polishing centers o, , o, ' aligned with the center of rotation of the cylindrical polishing F14 disc 60.

After that, by polishing the outer circumference of the ingot W using the cylindrical polishing machine 60, the final finished diameter of the ingot W matches the calculated dimension (maximum diameter that allows circular polishing), and unlike the conventional method, this final diameter It is possible to know the diameter of the point in advance.

(Effects of the Invention) As is clear from the above description, according to the present invention, the polishing center of an ingot is analytically determined based on the cross-sectional measurement data of the ingot, and the setting device connects this polishing center with the rotation of the cylindrical polishing disk. Since the ingot is set on the cylindrical polishing machine so that the centers are aligned, the ingot can be centered and set accurately and efficiently without relying on the operator's skill and intuition. can get.

[Brief explanation of drawings]

Figure 1 shows automatic centering according to the present invention? Front view of c position, 2nd
3 is a side view of the support section, FIG. 4 is an enlarged sectional view of the marking section of the device, FIG. 5 is a process chart showing the procedure of the centering device, and FIG. 6(a) - (d) are explanatory diagrams of the centering principle, Fig. 7 is a front view of the setting device, Fig. 8 is a side view of the same, Fig. 9 is a perspective view showing the direction of adjustment force in ingot alignment, and Fig. 10 is A schematic configuration diagram of the set device a, and FIGS. 11(a) to 11(e) are views showing the display screen of the monitor. 1- Automatic centering device, 5 a , 5 b , 5
c ・-, Indicator (measuring section), 8-... Marking section, 14... Supporting section, 39... CPU (computing section), 50... Setting device, 53... Chuck section,
54... Alignment section, 60... Cylindrical polishing machine, W
···ingot. Figure 2 Patent applicant Shin-Etsu Semiconductor Co., Ltd.

Claims (4)

[Claims] (1) A support part that supports the ingot, a measurement part that measures the cross-sectional shape of the ingot supported by the support part at multiple locations in the axial direction, and polishing based on the cross-sectional shape of the ingot measured by the measurement part. An automatic ingot centering device comprising: a calculation unit that calculates the center; and a marking unit that marks the polishing center calculated by the calculation unit on both end faces of the ingot. (2) The marking section includes a marking pen supported with its tip facing inside a cylindrical clamp shaft constituting the supporting section, and a moving means for moving the marking pen in the axial direction of the ingot. 2. The automatic ingot centering apparatus according to claim 1, further comprising a moving means for moving the marking pen in a direction perpendicular to the axis of the ingot. (3) a chuck unit that chucks the ingot whose polishing center has been marked by the automatic centering device;
a monitor section that monitors the polishing center marked on the ingot chucked by the chuck section; an alignment section that aligns the polishing center monitored by the monitor section with the rotation center of the cylindrical polishing disk; and after the alignment is completed. An ingot setting device that includes a conveyor section that conveys ingots to a cylindrical polishing machine. (4) An automatic cylindrical polishing device that includes the automatic centering device, setting device, and cylindrical polishing disk.