JP3412852B2 - Single crystal ingot marking device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a marking for a single crystal ingot for providing an identification mark on the surface of the single crystal ingot to indicate the direction of the crystal lattice plane existing inside the single crystal ingot. Regarding the device.

[0002]

2. Description of the Related Art In the field of IC manufacturing, various processes such as film formation, masking, etching, aluminum wiring, and dicing are performed on a disk-shaped Si wafer formed of Si (silicon) single crystal. As is well known, a single crystal is a substance in which the orientation of the atomic arrangement inside the crystal, that is, the direction of the crystal axis is perfectly aligned throughout the crystal. The direction of this crystal axis is usually called an azimuth, and in the above IC manufacturing process, the process is performed with the crystal orientations of a plurality of Si wafers to be processed always oriented in a fixed direction. It must be.

Conventionally, in order to know the crystal orientation of a Si wafer, as shown in FIG.
Of the orientation flat, which is commonly called an orientation flat, or a triangular groove 3 is formed as shown in FIG.
The crystal orientation inside the wafer 1 is determined by the groove 3 and the like.

The Si wafer 1 is manufactured by thinly cutting a cylindrical Si single crystal ingot 4 as shown in FIG. 5 or FIG. Orientation flat 2 and groove 3
Is formed by, for example, drawing a scribe line L3 at a fixed position with respect to the crystal orientation inside the ingot, and axially cutting, polishing, etc. machining the Si single crystal ingot 4 with reference to the scribe line L3. It

As a marking device for providing a marking line as described above on a single crystal ingot, a marking device utilizing X-ray diffraction as shown in, for example, FIG. 9 is conventionally known. This conventional device has a base 26 with a stand 27.
And a one-way slider 28 that reciprocates linearly in one direction on the base 26 toward or away from the stand 27,
A rotary table 9 that can freely rotate on a one-way slider 28 and a flat guide plate 29 fixed to a stand 27.
And an X-ray optical system having an X-ray source 6 and an X-ray counter 7.

The single crystal ingot 4 to be marked is placed on the rotary table 9. Then, by moving the slider 28 toward the stand 27,
The side surface of the ingot 4 is brought into contact with the guide plate 29 for positioning. Then, while rotating the rotary table 9 as shown by the arrow Q, the X-rays emitted from the X-ray source 6 are applied to appropriate positions on the side surface of the ingot 4. When the X-rays enter the crystal lattice plane in the ingot 4 at the Bragg angle, the X-rays are diffracted and satisfy the diffraction condition, and the diffracted X-rays are detected by the X-ray counter 7. When the X-ray counter 7 detects the diffracted X-rays, the rotation of the rotary table 9, that is, the rotation of the single crystal ingot 4 is stopped, and a marking line is drawn on the upper surface of the ingot 4 at a proper position using a ruler or the like. In this way, the marking line is always produced at a fixed position with respect to the crystal lattice plane in the ingot 4. The slider 28 and the rotary table 9 are moved manually by hand or indirectly by using a power transmission means such as a gear.

[0007]

However, the conventional marking device described above has a problem that the guide plate 29 is worn. Further, it is difficult to match the center of rotation of the rotary table 9 with the central axis of the ingot 4. Therefore, when the rotary table 9 is rotated to rotate the ingot 4, the ingot 4 rotates in an eccentric state, which is stable. There was also a problem that the marking work could not be done.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a marking device capable of performing a stable marking operation and having a long life.

[0009]

In order to achieve the above-mentioned object, a marking device for a single crystal ingot according to the present invention comprises:
An X-ray source that irradiates a single crystal ingot with X-rays, an X-ray detection unit that detects a diffraction line diffracted by the single crystal ingot, a two-way slide table that can freely translate in a plane, and two directions thereof. A rotary table that is placed on a slide table and can rotate freely, two guide rollers that contact the outer peripheral surface of the single crystal ingot, and a vertical bisector relating to the line segment that connects the two guide rollers. An elastic roller disposed, a roller moving means for moving the elastic roller toward or away from the two guide rollers, and a roller rotating means for rotating the elastic roller around its central axis. It has a feature.

[0010]

The single crystal ingot, which is an object to be provided with an identification mark such as a marking line, is placed on the rotary table. Then, the elastic roller is moved by the roller moving means.
The single crystal ingot is moved toward the individual guide rollers and pressed against the guide rollers to be positioned. Since the single crystal ingot is placed on the rotary table and the slide table, the single crystal ingot is pushed by the elastic roller and freely moved in parallel and rotationally to be positioned at the position where it comes into contact with the two guide rollers. In this positioning state, the single crystal ingot is irradiated with X-rays, and the elastic roller is rotated by the roller rotating means to rotate the single crystal ingot. When the single crystal ingot rotates, the X-ray is diffracted when the incident angle of the X-ray incident on the crystal lattice plane inside the single crystal ingot matches the Bragg angle, and the diffraction line is detected by the X-ray detection means. When the diffraction line is detected, the rotation of the single crystal ingot is stopped and an identification mark is provided on the surface of the single crystal ingot.

The single crystal ingot placed on the slide table is easily moved in parallel and rotationally by being pressed by the elastic roller, and is fixed by being supported at three points by the two guide rollers and the elastic roller. The X-ray irradiation position is accurately positioned.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a marking device for a single crystal ingot according to the present invention. This marking device includes a support base 5, a slide table 8 provided on the support base 5 and freely movable in parallel in two directions of X and Y orthogonal to each other, and an XY slide table 8 thereof.
And a rotatable table 9 which is rotatable above the table. The single crystal ingot 4 to be marked, for example, the Si single crystal ingot, is placed on the rotary table 9.

A stand 10 is arranged on the front side (right side in the figure) of the XY slide table 8, and a resilient roller 12 is supported by a bar-shaped arm 11 extending from the stand 10. The elastic roller 12 is formed of an elastic material, such as rubber, into a cylindrical shape. Elastic roller 12
Is integrated with a belt wheel 13 disposed therebelow, and when the belt wheel 13 is rotated by an endless belt 14 hung on the belt wheel 13, the belt wheel 13
Rotates together with. The endless belt 14 is connected to a well-known rotation transmission mechanism (not shown) inside the minute rotation drive device 15 fixedly installed on the stand 10. This rotation transmission mechanism is provided with a knob 16 exposed to the outside.
The endless belt 14 can be rotated by a desired distance in any forward or reverse direction by rotating the knob 16 in either forward or reverse direction by a desired angle. The elastic roller 12 is rotated in the forward and reverse directions by an arbitrary angle by the circumferential movement of the endless belt 14.

A bracket 18 having a U-shaped cross section is fixed to the back side (left side in the figure) of the support base 5, and a guide roller 19 is attached to the upper end of the bracket 18 so as to be axially rotatable. As shown in FIG. 2, two guide rollers 19 are provided. In FIG. 1, the stand 10 is
While being guided by the guide plate 17 extending from the support base 5, the two guide rollers 19 move linearly toward or away from the two guide rollers 19 as indicated by an arrow BB ′. Also,
As shown in FIG. 2, the center of rotation of the elastic roller 12 is located on the perpendicular bisector L2 with respect to the line segment L1 connecting the two guide rollers 19.

In FIG. 1, a pen stand 21 which is vertically movable is provided on the rear side surface of the bracket 18. Then, a slider 23 slidably fitted to a straight guide protrusion 22 formed on the upper end surface of the pen stand 21.
The diamond pen 24 is fixed to the tip of the and hangs down.

An X-ray diffraction goniometer having an X-ray source 6 and an X-ray counter 7 as X-ray detection means is arranged around the rotary table 9. This goniometer is capable of rotating around the axis J5, that is, so-called ω rotation, by integrating all the above-mentioned members installed on the support base 5. The axis line J5 is an axis line passing through the incident point P of the X-ray on the single crystal ingot 4.

The operation of the single crystal ingot marking device having the above structure will be described below.

Single crystal ingot 4 to be marked
Since the orientation of the crystal lattice plane inside is known, first, the X-ray source 6 and the X-ray counter 7 are installed at the positions satisfying the diffraction condition with respect to the crystal lattice plane. After that, the single crystal ingot 4 to be marked is placed on the rotary table 9. Although the single crystal ingot 4 has a very large weight, the work itself of placing it on the turntable 9 can be performed without much difficulty. The ingot 4 is merely placed on the turntable 9 and no measures are taken to secure it.

Next, as shown in FIG. 2, the stand 10 is moved toward the guide roller 19 to bring the elastic roller 12 into contact with the ingot 4, and the ingot 4 is pushed toward the guide roller 19. By this pressing operation, the ingot 4 moves in parallel in the direction of the guide rollers 19 and finally contacts the two guide rollers 19 and stops. In this state, the single crystal ingot 4 is supported at three points by the two guide rollers 19 and the elastic roller 12, and is always accurately positioned at a fixed position. In this positioned state, the X-rays emitted from the X-ray source 6 enter the outer peripheral side surface of the single crystal ingot 4. At this time, when the rotating knob 16 is rotated to gradually rotate the single crystal ingot 4 itself around the central axis J4, when the incident angle of the incident X-ray with respect to the internal crystal lattice plane of the ingot 4 matches the Bragg angle. X-rays are diffracted by the crystal lattice plane, and the diffraction lines are detected by the X-ray counter 7.

When the diffraction line is detected by the X-ray counter 7, the rotation of the single crystal ingot 4 is stopped, and the pen stand 21 and the slider 23 are operated to lightly move the diamond pen 24 to the upper end surface of the single crystal ingot 4. By pushing and further linearly moving the slider 23 along the guide protrusion 22, a marking line L3, that is, an identification mark is provided on the upper end surface of the ingot 4. As can be easily understood, the scribe line L3 is always formed at a constant position with respect to the crystal lattice plane inside the ingot detected by X-ray diffraction.

After the marking line L3 is thus imparted, the single crystal ingot 4 is removed from the marking device,
It is attached to an appropriate machining device, for example, a grinder or a cutting machine, and subjected to polishing or cutting with reference to the marking line L3, and an orientation flat surface 2 as shown in FIG. 5 or as shown in FIG. A groove 3 for different identification is formed.

According to the present embodiment, the orientation flat surface 2 or the orientation flat surface of the single crystal ingot 4 (FIG. 5 or 6) after the V groove 3 is formed by exchanging some of the components. It is possible to inspect whether or not the groove 2 or the groove 3 is accurately formed at a predetermined position with respect to the internal crystal lattice plane. FIG. 7 shows an example of the configuration of such a crystal orientation inspection apparatus when the V-groove 3 for identifying the crystal orientation is formed in the single crystal ingot 4. The difference between this inspection device and the marking device shown in FIG. 1 is that instead of the stand 10 provided with the elastic roller 12 for pressing the ingot,
That is, the stand 30 provided with the wedge-shaped fitting member 31 is slidably arranged on the guide plate 17.
As shown in FIG. 8, the wedge-shaped fitting member 31 is elastically biased toward the XY slide table 8 by the compression spring 32. And this wedge-shaped fitting member 31
Is located on the vertical bisector L2 with respect to the line segment L1 connecting the two guide rollers 19.

In this apparatus, the inspection is carried out as follows.

First, the Si single crystal ingot 4 to be inspected, which is provided with the V groove 3 for identifying the orientation, is placed on the rotary table 9. The ingot 4 is merely placed on the turntable 9 and no measures are taken to fix it. Next, the wedge-shaped fitting member 31 is fitted into the V groove 3, and the stand 30 is pushed to move the ingot 4 toward the guide rollers 19, 19.
At this time, the ingot 4 freely moves in parallel in the two directions of X and Y by the action of the XY slide table 8, and further rotates appropriately around the axis J4 by the action of the rotary table 9, and the ingot 4 of the two guide rollers 19 moves. It is set to a fixed position where it contacts both. In this set state, X
X-rays are emitted from the radiation source 6, and the X-rays R1 enter the outer peripheral side surface of the ingot 4.

With the X-ray R1 incident on the ingot 4, the support 5 and hence the ingot 4 are rotated by ω about the axis J5 by the action of the goniometer. The angle of incidence of the X-ray R1 on the ingot 4 gradually changes due to this ω rotation, but the diffraction condition between the crystal lattice plane in the ingot 4 and the incident X-ray R1 changes at an appropriate angular position during this ω rotation. When satisfied, X-ray diffraction occurs in the ingot 4, and the diffracted X-ray is detected by the X-ray counter 7. By measuring the ω rotation angle when the diffracted X-ray is detected by the X-ray counter 7, it is possible to know the tilt angle deviation of the crystal lattice plane in the ingot 4 from the reference position. This angular deviation is, of course, equivalent to the deviation of the V groove 3 from the normal position.

During the X-ray diffraction measurement as described above, the ingot 4 has two guide rollers 19 and a wedge-shaped fitting member 31.
Since it is supported at three points by, it is always arranged at a fixed position with respect to the V groove 3. Therefore, an extremely stable and highly reliable inspection can be performed.

Although the present invention has been described with reference to one embodiment, the present invention is not limited to this embodiment. For example, the identification mark for identifying the crystal lattice plane in the single crystal ingot is not limited to the diameter line L3 drawn by scribe on the upper end surface of the single crystal ingot, and may have any other shape or pattern. Good. The forming method is not limited to scribing, and may be drawn with ink or the like.

[0028]

According to the present invention, the elastic roller rotates the ingot itself, and the ingot is supported by the two guide rollers.
The rotation of the ingot has become smoother, and stable marking work has become possible. In addition, the guide roller wears less than in the case where a flat guide plate is used, so that the life of the marking device is extended. Furthermore, according to the marking device of the present invention, by changing a part of the members, the marking device can be used as an inspection device for inspecting whether or not the marking is produced at a predetermined position.

[0029]

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a single crystal ingot marking device according to the present invention.

FIG. 2 is a plan view of the marking device when viewed from above.

FIG. 3 is a perspective view showing an example of a wafer cut out from a single crystal ingot.

FIG. 4 is a perspective view showing another example of a wafer cut out from a single crystal ingot.

FIG. 5 is a perspective view showing an example of a single crystal ingot.

FIG. 6 is a perspective view showing another example of a single crystal ingot.

FIG. 7 is a perspective view showing an application use example of the embodiment shown in FIG.

FIG. 8 is a plan view of the application use example shown in FIG.

FIG. 9 is a perspective view showing an example of a conventional marking device for a single crystal ingot.

[Explanation of symbols]

4 Single crystal ingot 6 X-ray source 7 X-ray counter (X-ray detection means) 8 slide table 9 rotating table 10 stand (roller moving means) 13 Belt car (roller rotation means) 14 Belt (roller rotation means) 15 Micro rotation drive device (roller rotation means) 17 Guide plate (roller moving means) 19 Guide roller 21 Pen stand 23 Slider 24 Diamond pen (scribble pen) Line segment connecting L1 guide rollers L2 vertical bisector L3 marking line (identification mark)

Claims (2)

(57) [Claims] 1. A marking device for forming an identification mark on a single crystal ingot at a constant surface position with respect to an internal crystal lattice plane of the single crystal ingot, wherein X is directed toward the single crystal ingot.
In a marking device for a single crystal ingot, which comprises an X-ray source for irradiating a beam and an X-ray detection means for detecting a diffracted X-ray diffracted by the single crystal ingot, a bidirectional slide table that can freely translate in a plane , A rotary table placed on a bidirectional slide table, on which a single crystal ingot can be freely rotated and on which a single crystal ingot is placed, two guide rollers abutting on the outer peripheral surface of the single crystal ingot, and those two guide rollers Elastic roller arranged on a perpendicular bisector related to the line segment connecting the two, a roller moving means for moving the elastic roller toward or away from the two guide rollers, and the elastic roller around its central axis. A single-crystal ingot marking device having a roller rotating means for rotating the single crystal ingot. 2. A single crystal ingot having a scribe line for drawing a scribe line on the surface of the single crystal ingot, and a pen stand for moving the scribe line in parallel with respect to a slide table. A single crystal ingot marking device as described.