JPH04322965A - Automatic cylinder grinding method and device - Google Patents

Abstract

PURPOSE:To perform ingot cylindrical grinding, orientation-flat grinding and tailpiece stepping successively and automatically by installing an ingot crystal habit line position detecting means, an ingor tailpiece form measuring means, both ingot cylindrical grinding and tailpiece step grinding means and an orientation-flat grinding means, respectively. CONSTITUTION:This device is provided with a grinding information inputting means, an ingot handling means, an ingot rotation stopping means 2M and two ingot diameter measuring means 38, 40. Also it is provided with a grinding information judging means, an ingot crystal habit line position detecting means 26 and its storage means, a grinding means 6 for ingot cylindrical grinding and tailpiece step grinding, an ingot tailpiece form measuring means 10, a means 42 for checking the direction of an ingot ground by an X-ray diffraction peak, and an ingot orientation-flat grinding means 8. These means are operated in order by a command part C on the basis of the inputted grinding information, thus a monocrystal ingot is machined for cylindrical grinding, orientation-flat grinding and tailpiece steeping in succession.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention automatically performs cylindrical grinding of ingots, orientation flat (abbreviated as orientation flat in this specification) grinding, and stepped grinding of ingot tails for cutting out samples for lifetime measurement. The present invention relates to an automatic cylindrical grinding method and device that enables automatic cylindrical grinding.

0002

2. Description of the Related Art Semiconductor substrates used in the manufacture of semiconductor integrated circuit devices are round rod-shaped single crystals produced by a single crystal growth method, namely the Czochralski method (CZ method) or the floating zone melting method (FZ method). After centering the ingot, its outer periphery is ground with a cylindrical grinder to finish it to a predetermined diameter, and an orientation flat is cut and formed at a predetermined position to obtain a substantially cylindrical single crystal ingot. is cut approximately perpendicular to its long axis direction, that is, in accordance with a predetermined crystallographic direction, and both sides of the roughly disc-shaped piece obtained by cutting are lapped and etched, and finally one side is polished. can get.

[0003] Conventionally, the above-mentioned cylindrical grinding and orientation flat grinding of single crystal ingots have been performed separately, and cutting out samples for measuring lifetime has also been performed as a separate process, which is time-consuming and time-consuming. The processing efficiency was poor.

0004

[Problems to be Solved by the Invention] The present invention was invented in view of the above-mentioned prior art. It is an object of the present invention to provide an automatic cylindrical grinding method and device that enables continuous and automatic grinding.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the automatic cylindrical grinding method of the present invention includes the steps of (a) setting an ingot in a predetermined position, and (b) measuring the diameter of the set ingot. (c) determining whether or not to perform orientation flat grinding on this ingot; (d) detecting and storing the habit line position of this ingot;
e) cylindrical grinding of the ingot; (f) measuring the diameter of the ground ingot; and (g)
a step of determining whether to perform tail step grinding on this ingot; (h) a step of measuring the shape of the tail portion of this ingot; (i) a step of performing tail step grinding on this ingot; ) a process of re-judging whether or not to perform orientation flat grinding on this ingot; (k) a process of aligning this ingot to the habit line memorized position; and (l) a process of determining the orientation of the cylindrically ground ingot by X-ray diffraction. (m) adjusting the angle of this ingot to match the orientation flat ground surface; (n) grinding this ingot to form the orientation flat surface; (o) the formed (p) A step of taking out the ingot which has been cylindrically ground and has an orientation flat surface formed thereon, and when performing cylindrical grinding, orientation flat grinding and tail stepped grinding on this ingot, the above (a)～
Perform step (p), omit steps (d) and (k) to (o) above if orientation flat grinding is not performed, and steps (h) and (i) above if step grinding of the tail section is not performed. is omitted.

The automatic cylindrical grinding apparatus of the present invention includes means for inputting grinding information, means for setting and taking out the ingot, means for stopping rotation of the ingot according to the input grinding information, and means for adjusting the diameter of the ingot. means for measuring, means for determining input grinding information, means for detecting the habit line position of the ingot, means for storing the detected habit line position of the ingot, and cylindrical grinding and tail stage of the ingot. A grinding means for performing additional grinding, a means for measuring the shape of the ingot tail, a means for confirming the orientation of the ground ingot by an X-ray diffraction peak, an orientation flat grinding means for forming an orientation flat surface by grinding the ingot, and the above-mentioned The apparatus includes a command section that sequentially operates each means based on input grinding information, and is capable of executing the automatic cylindrical grinding method described above.

[0007]

[Operation] In the present invention, it is necessary to detect the crystal habit line of the ingot and identify a predetermined orientation flat orientation plane, that is, the orientation flat grinding surface, by X-ray diffraction peak (X-ray measurement) using the position as a reference plane. Based on this recognition, it has become possible to automatically perform orientation flat grinding for each ingot.

[0008] Also, in identifying the orientation flat ground surface,
If the X-ray diffraction peak position matches the orientation flat orientation, you can simply perform orientation flat grinding, but if the X-ray diffraction peak position and the orientation flat orientation do not match,
The orientation flat grinding is performed after the orientation flat direction is matched with the determined orientation flat direction by rotationally positioning a specified angle based on the position detected by line measurement.

In the case of the above-mentioned method of directly detecting the X-ray diffraction peak position as the orientation flat orientation, it was necessary to adjust the incident angle θ of the X-ray according to the orientation flat orientation to be detected. When adjusting the angle after using the angle θ as a reference plane, there is an advantage that the troublesome work of adjusting the incident angle θ each time is unnecessary.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an example of the overall configuration of the apparatus of the present invention. The ingot or workpiece W can be rotated by a chuck 3 (Fig. 7) provided at the tips of workpiece rotation shafts 2, 2 that extend inwardly from a support D (Fig. 6) installed on the floor. It undergoes automatic cylindrical grinding processing while being held in place. The work rotation axis 2 is a motor 2
Rotationally driven by M. 4 is a grinding unit provided corresponding to the ingot or workpiece W, and houses a cylindrical grinding wheel unit 6, an orientation flat grinding wheel unit 8, and a tail shape measuring unit 10.

Reference numeral 12 denotes a traverse shaft connected to the grinding unit 4. As the traverse shaft 12 rotates, the grinding unit 4, that is, the cylindrical grinding wheel unit 6, the orientation flat grinding wheel unit 8, and the tail shape measuring unit 1, is rotated.
0 is configured to move left and right. The traverse shaft 12 is rotationally driven by a motor 12M. The cylindrical grinding wheel unit 6 is a means for grinding the peripheral surface of an ingot or a workpiece W into a cylindrical shape, and includes a coarse grinding wheel 6d and a coarse grinding wheel 6d respectively attached to the tips of support shafts 6b and 6c that project horizontally from the cylindrical grinding wheel unit 6a. It is equipped with a precision grindstone 6e. The support shafts 6b, 6c are rotationally driven by a motor 6M.

The orientation flat grinding wheel unit 8 performs orientation flat grinding on a predetermined position of a cylindrically ground ingot or workpiece W, and is attached to the tip of a support shaft 8b that projects horizontally from the orientation flat grinding wheel unit main body 8a. It is equipped with a grinding wheel 8c. The support shaft 8b is rotationally driven by a motor 8M. These cylindrical grinding wheel unit 6 and orientation flat grinding wheel unit 8 are connected to the control shaft 1
4, and when the control shaft 14 rotates, the cylindrical grinding wheel unit 6 and the orientation flat grinding wheel unit 8 move up and down, and the depth of cut for cylindrical grinding and the depth of cut for orientation flat grinding are controlled. It is becoming more and more popular. The control shaft 14 is rotationally driven by a motor 14M.

As shown in FIG. 2, the tail shape measuring unit 10 includes a support shaft 18 to which a roll 16 is attached at the bottom, an upper horizontal plate 20 to which the support shaft 18 is attached so as to be movable up and down, and an upper horizontal plate 20. A lower fixing plate 22 attached below the support shaft 18 in correspondence with the plate 20, and an upper horizontal plate 2
0 and the lower fixing plate 22 to bias the support shaft 18 and the lower fixing plate 22 downward, and a distance provided in the upper horizontal plate 20. It has a detection sensor 26. The distance detection sensor 26 detects the distance between the upper horizontal plate 20 and the lower fixed plate 22, and is electrically connected to the controller C. The tail shape measuring unit 10 is a means for calculating the grinding depth X according to the shape of the tail W1 in order to perform a step machining to form a step 30 on the tail W1 of the ingot or workpiece W.

A specific example of calculating the grinding depth will be explained based on FIGS. 2 to 4. For example, when forming a step 30 having a length from the edge A of the tail W1 of an ingot or workpiece W to a position B horizontally 10 cm away, the roll 16 of the tail shape measuring unit 10 is first placed at the edge A. When the tail shape measuring unit 10 is moved toward the tip of the tail W1 by rotating the traverse shaft 12, the upper horizontal plate 20 moves horizontally while maintaining its height. On the other hand, the support shaft 18 and the lower fixing plate 22 are also movable in the horizontal direction.
The roll 16 also moves downward due to the downward biasing force of the roll 16, that is, the roll 16 moves diagonally downward to position B along the slope of the tail portion W1, as shown in FIG.

FIG. 3 shows a graph of the movement of the tail shape measuring unit 10 detected by the distance detection sensor 26 at this time. As is clear from the figure, when the distance detection sensor 26 is moved horizontally by 10 mm on the coordinates of the traverse axis 12, the vertical distance detected by the distance detection sensor 26 is Xmm (X=X1 -X0:X
0 is the value of the distance detection sensor at edge A, and X1 is the value of the distance detection sensor at position B) is the grinding depth. As shown in Fig. 4, if the tail part W1 is ground vertically from the edge A to a depth of X mm, the length will be 10 mm.
A step portion 30 is formed.

In FIG. 5, reference numeral 32 denotes a diameter measuring machine for measuring the diameter of an ingot or a workpiece W, which has a pair of rotating shafts 34.
, 36, measuring members 38, 40 are movably attached to the measuring members 38, 40.
have. To measure the diameter of the ingot or workpiece W, the rotating shafts 34 and 36 are rotated until the measuring members 38 and 40 come into contact with the circumferential surface of the ingot or workpiece W, and the position of the measuring members 38 and 40 is determined and the diameter of the workpiece W is determined. Measuring member 3
This is done by detecting the interval between 8 and 40 contact stops. The rotating shafts 34 and 36 are rotationally driven by motors 34M and 36M.

Reference numeral 42 denotes an X-ray unit, which is installed on a slide table 44 installed on the side of the support base D, as shown in FIG. The slide table 44 is connected to the motor 4
It is possible to move in the direction perpendicular to the axis of the ingot or workpiece W according to the drive of the 2M. The X-ray unit 42 is provided with an arc-shaped goniometer stage 46. An X-ray generator 48 and an X-ray detector 50 are movably attached to the goniometer stage 46.
The mounting position of the line detector 50 can be arbitrarily adjusted.

[0018] Using this X-ray unit 42, the orientation flat direction is detected. That is, while rotating the ingot or work W in a predetermined direction at a slow speed, the X-ray generator 48 irradiates the surface of the ingot or work W at an incident angle θ (23.65° in the case of this embodiment). The X-rays are diffracted and detected by the X-ray detector 50 only when the crystal lattice plane of the ingot or workpiece W matches the X-ray incident angle θ. Then, the position of the X-ray diffraction peak detected by the X-ray detector 50 is found, and when the position is found, the rotation of the ingot or workpiece W is stopped. At this time, for example, in the case of an ingot whose pulling orientation is <111> and when forming an orientation flat surface on the (110) plane, the X-ray diffraction peak position of the ingot W coincides with a point on the desired orientation flat orientation. If orientation flat grinding is performed at the position, the required orientation flat surface can be obtained.

[0019] If the X-ray diffraction peak position matches the orientation flat orientation as described above, the orientation flat grinding can be carried out as is, but there are cases where the X-ray diffraction peak position and the orientation flat orientation do not match. In some cases, it is necessary to rotate and position the specified angle using the position detected by X-ray measurement as a reference to match the orientation flat orientation determined. For example, in the case of an ingot whose pulling orientation is <100> and when forming an orientation flat surface on the (100) plane, the position rotated by 45 degrees from the X-ray diffraction peak position of the ingot W is the point on the desired orientation flat orientation. If they match and grind the orientation flat at this position, the required orientation flat surface can be obtained. In the case of the above-described method of directly detecting the X-ray diffraction peak position as the orientation flat orientation, it was necessary to adjust the incident angle of the X-rays according to the orientation flat orientation to be detected. For example, in the case of the ingot whose pulling direction is <100> in the above example, when forming an orientation flat surface on the (100) plane,
It was necessary to set the incident angle θ to 34.56°. but,
According to this method, the incident angle θ is fixed at 23.6°, and after detecting the reference plane, the ingot is rotated again to adjust the angle to the orientation flat grinding surface.
This has the advantage of eliminating the need for the troublesome work of adjusting each time. Further, in the case of the ingot whose pulling orientation is <100> in the above example, no angle adjustment is necessary when forming an orientation flat surface on the (110) plane, so the adjustment angle may be considered to be 0°.

In FIG. 6, reference numeral 52 denotes a position sensor for detecting the distance to the ingot or workpiece W, and is attached to the height of the axis of the ingot or workpiece W of the X-ray unit 42.

The X-ray detector 50 of the X-ray unit 42 is integrally provided with a habit line detection sensor 54, as shown in FIG. This habit line detection sensor 54 is a type of optical sensor, and detects the presence or absence of a habit line L on the ingot surface as shown in FIG. 8 by irradiating light onto the ingot surface and receiving the light reflected from the surface. .

[0022] C is a controller that controls each of the above-mentioned devices, and includes motors 2M, 12M, 14M, 34M, 36
M, 42M and the distance detection sensor 26 are electrically connected. S is a sequencer for performing sequence control. P is an operation panel for inputting information necessary for automatic grinding to the automatic grinding device. Information input from this operation panel P includes the grinding diameter command value, crystal orientation code, presence or absence of orientation flat grinding, presence or absence of tail step processing, orientation flat grinding surface angle when performing orientation flat grinding, orientation flat grinding depth, etc. It is.

Next, the procedure for carrying out the automatic cylindrical grinding method of the present invention using the automatic cylindrical grinding apparatus having the above-described configuration will be explained according to the flowchart shown in FIG.

First, the above-mentioned various types of grinding information for performing automatic cylindrical grinding of a single crystal ingot or workpiece W pulled by a single crystal pulling device (not shown), ie, a grinding diameter command value, a crystal orientation code, and orientation flat grinding information, are collected. From the operation panel P, enter the presence or absence of tail step processing, the angle of the grinding surface of the orientation flat when grinding the orientation flat, and the depth of the orientation flat grinding.

First, the case where the pulled single crystal ingot W is subjected to cylindrical grinding, tail step processing and orientation flat grinding will be described.

[0026] The ingot or workpiece W is attached to the chuck 3
(FIG. 1), the ingot or work W is set horizontally and rotatably (step 100), and its diameter is then measured by the diameter measuring machine 32. (Step 101).

The presence or absence of orientation flat grinding is determined from the grinding information input from the operation panel P (step 102), and since orientation flat grinding is present in this example, rotation of the ingot or workpiece W is subsequently started, and the crystal The position of the habit line L is detected by the habit line detection sensor 54, and the position is stored in the controller C (step 103). The grinding depth is set according to the given grinding diameter command value, and the cylindrical grinding wheel unit 6 performs cylindrical grinding according to this command (step 104). When the cylindrical grinding is completed, the rotation is stopped and the diameter is measured again by the diameter measuring machine 32 (step 105).

[0028] Based on the input grinding information, it is determined whether the tail part has been stepped (step 106), and in this example, since the tail part has been stepped, the shape of the tail part W1 is measured by the tail part shape measuring unit 10. (Step 107), predetermined tail step grinding is performed using the cylindrical grinding wheel unit 6 (Step 108). The presence or absence of orientation flat grinding is determined again from the grinding information input from the operation panel P (step 109),
In this example, since orientation flat grinding is performed, the work rotation shaft 2 is rotated to align the position of the ingot W with the habit line position stored in step 103 (step 110).
. While rotating the ingot W at a slow speed, the X-ray diffraction peak on the side surface of the ingot is detected by the X-ray detector 50 (step 111).

[0029] According to the information on the orientation flat direction inputted from the operation panel P, the angle of the ingot W (rotate the ingot at a predetermined angle. If rotation is not required, the angle is 0) of the ingot W on the orientation flat grinding surface is adjusted (step 112). ), the orientation flat grinding is performed using the orientation flat grinding wheel unit 8 (step 113). Diameter measuring machine 3 for cutting margin during orientation flat grinding
2 (step 114).

[0030] The ingot or workpiece W is rotated around the workpiece rotation axis 2.
to finish the cylindrical grinding work (step 11).
5).

Furthermore, a case will be described in which the single crystal ingot W is not subjected to tail step processing and orientation flat grinding. Similarly, set the ingot W (step 10
0), and then measure its diameter (step 101).

The presence or absence of orientation flat grinding is determined from the grinding information input from the operation panel P (step 102), and since orientation flat grinding is not required in this example, step 103 is omitted and cylindrical grinding is performed (step 104). Once the cylindrical grinding is completed, its diameter is measured again (step 105).
. Based on the input grinding information, it is determined whether the tail part is stepped or not (step 106). In this example, since the tail part is not stepped, steps 107 and 108 are omitted.

The presence or absence of orientation flat grinding is determined again from the grinding information input from the operation panel P (step 109), and since orientation flat grinding is not required in this example, the ingot or work W is taken out from the work rotating shaft 2. The cylindrical grinding operation ends (step 115).

[0034] Furthermore, when either the tail step processing or the orientation flat grinding is performed on the single crystal ingot or the workpiece W, it is automatically performed according to the respective work procedures. The explanation of is omitted to avoid duplication.

[0035]

As described above, according to the present invention, a single crystal ingot is subjected to continuous cylindrical grinding, orientation flat grinding, and stepped tail grinding for cutting out samples for lifetime measurement. The great effect is that it can be carried out automatically, and that orientation flat grinding or tail step grinding can be omitted at will.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating an embodiment of the device of the present invention.

FIG. 2 is a schematic explanatory diagram showing an example of an ingot tail shape measuring unit.

FIG. 3 is a graph showing an example of distance information from a distance detection sensor.

FIG. 4 is an explanatory diagram showing an example of tail stepped grinding.

FIG. 5 is a schematic explanatory diagram showing an example of a diameter measuring device.

FIG. 6 is a schematic side view showing an embodiment of the device of the present invention.

FIG. 7 is an explanatory diagram showing an example of an X-ray unit of the apparatus of the present invention.

FIG. 8 is a partial perspective view of a single crystal ingot.

FIG. 9 is a flowchart showing the procedure for carrying out the method of the present invention.

[Explanation of symbols]

2 Work rotation axis 3 Chuck 6 Cylindrical grinding wheel unit 8 Orientation flat grinding wheel unit 10　Tail shape measurement unit 32 Diameter measuring machine 42 X-ray unit P Operation panel S Sequencer C Controller W Single crystal ingot

Claims (2)

[Claims] Claim 1: (a) a step of setting an ingot in a predetermined position; (b) a step of measuring the diameter of the set ingot; and (c) a step of determining whether or not to perform orientation flat grinding on this ingot. (d) detecting and storing the habit line position of this ingot; (e) cylindrical grinding of this ingot; (f) measuring the diameter of this ground ingot; (g) ) a step of determining whether or not to perform tail step grinding on this ingot; and (h)
(i) measuring the shape of the tail of the ingot;
a step of performing tail step grinding on this ingot; (j) a step of re-judging whether or not to perform orientation flat grinding on this ingot; (k) a step of aligning this ingot with a habit line memory position; (l) Confirming the orientation of the cylindrically ground ingot by X-ray diffraction peaks, and (m
) A step of adjusting the angle of this ingot to match the orientation flat grinding surface, (n) a step of grinding this ingot to form an orientation flat surface, (o) a step of measuring the formed orientation flat cutting margin, (p) taking out the ingot which has been cylindrically ground and has an orientation flat surface formed thereon; and when performing cylindrical grinding, orientation flat grinding and tail stepped grinding on this ingot based on the input grinding information, the above Perform the steps (a) to (p), omit the steps (d) and (k) to (o) above if orientation flat grinding is not performed, and skip the steps (h) above if tail step grinding is not performed.
An automatic cylindrical grinding method characterized in that the steps (i) and (i) are omitted. 2. A means for inputting grinding information, a means for setting and taking out an ingot, a means for stopping rotation of the ingot according to the input grinding information, a means for measuring the diameter of the ingot, and a means for inputting the input grinding information. means for determining the grounding information, means for detecting the habit line position of the ingot, means for storing the detected habit line position of the ingot, and grinding means for performing cylindrical grinding and tail stepped grinding of the ingot. , a means for measuring the shape of the ingot tail, and
A means for confirming the orientation of the ground ingot based on a line diffraction peak, an orientation flat grinding means for grinding the ingot to form an orientation flat surface, and a command unit that sequentially operates each of the above means based on input grinding information. An automatic cylindrical grinding device comprising: an automatic cylindrical grinding device, wherein the grinding step according to claim 1 can be automatically executed.