JPH09283601A - Direction deciding method for semiconductor wafer and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor wafer direction deciding method without mechanical marking which gives damage to the single crystal structure of a semiconductor wafer, and to provide its device. SOLUTION: The direction of a semiconductor wafer 1B is decided by rotating it around B-axis vertical to a surface 11 when it is being conveyed, a diffracted X-rays 7A, generated by projecting primary X-rays 5A to the surface 11, are detected, the prescribed crystal lattice surface in the semiconductor wafer 1B is specified from the result of the above-mentioned detection, and by controlling the rotation of the semiconductor wafer 1B in such a manner that the prescribed crystal lattice surface becomes the prescribed positional relation against the conveying direction A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the direction of a semiconductor wafer, which is a single crystal, without making a mark by mechanical processing that damages the single crystal structure, and an apparatus used therefor. It is a thing.

[0002]

2. Description of the Related Art In a semiconductor wafer made of a single crystal such as silicon or gallium arsenide, it is necessary to unify the direction of the wafer in each process of forming a circuit on the surface thereof. Therefore, conventionally, as shown in FIG. 8, at the stage of the substantially cylindrical ingot 30 that is the base material of the semiconductor wafer,
When the height direction of the cylinder is the z axis and the two axes perpendicular to the z axis are perpendicular to the x axis and the y axis, for example, a single crystal lattice plane (001) plane 31 is formed on the plane perpendicular to the z axis. The (100) plane 32 is cut out on the side surface of the cylinder so as to be aligned. In this way, as shown in the plan view of FIG. 9, when the ingot 30 is sliced into a plurality of pieces in the direction perpendicular to the z-axis to produce a substantially disk-shaped wafer 33, the (100) plane 32 cut out is prepared. The mark indicates the direction of the semiconductor wafer 33. The cut surface 32 is called an orientation flat 32, but a V-shaped cut called a notch may be made instead of this.

[0003]

However, in order to mark the orientation flat 32 and the notch,
When the ingot 30 is mechanically processed, first, the surface area of the wafer 33 is reduced by the amount removed by the processing, and further, the single crystal structure near the processed portion, that is, the orientation flat 32 or the notch is damaged. Since it cannot be received and used as a circuit board, the area available on the surface as a circuit board decreases. Therefore, the utilization efficiency from the ingot 30 to the semiconductor wafer 33 is insufficient, and as a result, the cost per chip formed on the semiconductor wafer 33 cannot be sufficiently reduced. This problem is particularly important under the present circumstances where an ingot 30 and a semiconductor wafer 33 having a larger diameter are being manufactured in order to reduce the cost per chip.

The present invention has been made in view of the above-mentioned conventional problems, and determines the direction of a semiconductor wafer which is a single crystal without making a mark by mechanical processing that damages the single crystal structure. An object of the present invention is to provide a method and a device used therefor.

[0005]

In order to achieve the above object, in the method of claim 1, first, a disk-shaped semiconductor wafer is rotated around an axis perpendicular to the surface in a transfer path. Next, the surface of the rotating semiconductor wafer is irradiated with primary X-rays, and the generated diffracted X-rays are detected. Then, a predetermined crystal lattice plane in the semiconductor wafer is specified from the detection result, and the rotation of the semiconductor wafer is controlled so that the specified crystal lattice plane has a predetermined positional relationship with respect to the transport direction,
Determine the orientation of the semiconductor wafer.

In the method of the second aspect, first, the disk-shaped semiconductor wafer is rotated about an axis perpendicular to the surface in the transfer path. Next, the side surface of the rotating semiconductor wafer is irradiated with primary X-rays, and the generated diffracted X-rays are detected. Then, a predetermined crystal lattice plane in the semiconductor wafer is specified from the detection result, and the rotation of the semiconductor wafer is controlled so that the specified crystal lattice plane has a predetermined positional relationship with respect to the transport direction. Determine the direction.

According to a third aspect of the present invention, there is provided a semiconductor wafer orientation determining apparatus, which comprises: a transfer means for transferring a disk-shaped semiconductor wafer; and a rotation means for rotating the semiconductor wafer around an axis perpendicular to the surface of the semiconductor wafer in the transfer path. Is equipped with. Further, it is provided with an X-ray source for irradiating the surface of the rotating semiconductor wafer with primary X-rays, and a detector for detecting diffracted X-rays generated from the semiconductor wafer. Further, it is provided with a control means for specifying a predetermined crystal lattice plane in the semiconductor wafer from the detection result and controlling the rotating means so that the specified crystal lattice plane has a predetermined positional relationship with the transport direction. .

According to a fourth aspect of the present invention, there is provided a semiconductor wafer orientation determining apparatus, which first comprises a transfer means for transferring a disc-shaped semiconductor wafer, and a rotating means for rotating the semiconductor wafer about an axis perpendicular to the surface of the semiconductor wafer in the transfer path. Is equipped with. Further, an X-ray source for irradiating the side surface of the rotating semiconductor wafer with primary X-rays and a detector for detecting diffracted X-rays generated from the semiconductor wafer are provided. Further, it is provided with a control means for specifying a predetermined crystal lattice plane in the semiconductor wafer from the detection result and controlling the rotating means so that the specified crystal lattice plane has a predetermined positional relationship with the transport direction. .

[0009]

According to the invention of claim 1 or 3,
The direction of the semiconductor wafer, which is a single crystal, is determined by X-ray optics determination from the crystal orientation, and the direction is determined. Therefore, the surface area of the semiconductor wafer does not decrease due to the marking by mechanical processing, and the circuit board is used as a circuit board. It does not reduce the available area. Therefore, the cost per chip formed on the semiconductor wafer can be sufficiently reduced.

According to the invention of claim 2 or 4, in addition to the effect of the invention of claim 1 or 3, since the side surface of the semiconductor wafer is irradiated with the primary X-rays, the X-rays are directed above the semiconductor wafer. The effect is that it can be applied even when there is no space to install the source or detector.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method according to a first embodiment of the present invention will be described with reference to the drawings. First, an apparatus used in this method will be described. As shown in the side view of FIG.
This device is a disc-shaped semiconductor wafer 1A, 1B, 1C.
(See the plan view of FIG. 2) Two conveyor means 2A, 2B such as a belt conveyor, and two conveyor means 2A,
The rotation means 3 provided between the 2B and 2B. Here, the gap between the two transfer means 2A, 2B is set smaller than the diameter of the semiconductor wafers 1A, 1B, 1C.
The rotating means 3 includes a disk-shaped table 3a (see FIG. 2) on which the semiconductor wafers 1A, 1B and 1C are placed, and the semiconductor wafer 1 which is vertically downward from the center of the table 3a.
It has a rotating shaft 3b extending in a direction perpendicular to the surface 11 of A, 1B, 1C, and a motor 3c for rotating the rotating shaft 3b around the axis B. The diameter of the table 3a is equal to that of the two transport means 2
It is set to be slightly smaller than the gap between A and 2B.

Below the rotating means 3, an elevating means 4 for vertically moving the rotating means 3 is provided. Above the rotating means 3, needle-shaped primary X-rays 5A are formed on the surface 11 of the semiconductor wafer 1B rotated by the rotating means 3.
The X-ray source 6A for irradiating the semiconductor wafer 1B and the detector 8 for detecting the diffracted X-ray 7A generated from the semiconductor wafer 1B are provided. Here, the X-ray source 6A includes, for example, an X-ray tube 16 that is a point light source that radially generates X-rays, and a pinhole-shaped hole 15.
and a slit 15 having a. Further, this apparatus is provided with control means 9 which is a computer for controlling the rotating means 3 based on the detection result of the detector 8 of FIG.
The control means 9 also controls the elevating means 4 and the conveying means 2A, 2B. Note that the control means 9 is not shown in FIG. Further, the X-ray source 6 and the detector 8 are fixed to the ceiling via a support mechanism (not shown), and the transfer means 2
A, 2B and the elevating means 4 are fixed to the floor via a support mechanism (not shown).

In the method of the first embodiment using this apparatus, first, the semiconductor wafers 1A, 1B and 1C are transferred in the transfer direction A by the transfer means 2A and 2B shown in FIG. At this time, the two transfer means 2A and 2B are controlled by the control means 9.
Synchronize and operate at the same transport speed. Further, the elevating means 4 is controlled by the control means 9 so that the upper surface of the table 3a of the rotating means 3 is flush with or slightly below the upper surfaces of the conveying means 2A, 2B (indicated by the solid line in the figure). Then, the rotating means 3 is made to stand by. Here, the two transport means 2A, 2
Since the gap B is smaller than the diameter of the semiconductor wafers 1A, 1B, and 1C, the semiconductor wafer 1B originally located at the position 1A in FIG. On the table 3a, the rear part is pushed forward by the conveying means 2A, and the front part is pulled up by the conveying means 2B, and conveyed to the position shown by the solid line in FIG. 1, that is, just above the table 3a (see FIG. 2).

The fact that the semiconductor wafer 1B has been transferred to just above the table 3a is detected by a not-shown visual sensor or the like, and the control means 9 causes the two transfer means 2A and 2B to be transferred.
Stop at the same time. Then, the control means 9 controls the elevating means 4 to raise the rotating means 3 to the ascending position for raising the semiconductor wafer 1B from the transfer means 2A, 2B, as shown by the chain double-dashed line in FIG. Further, the rotating means 3 is controlled to control the semiconductor wafer 1 mounted on the table 3a.
Rotate B about an axis perpendicular to its surface 11. At the same time, the surface 11 of the semiconductor wafer 1B is irradiated from the X-ray source 6A with a needle-shaped primary X-ray 5A, which is, for example, a Cu-Kα ray, and the generated diffracted X-ray 7A is detected by the detector 8.

Now, it is assumed that the semiconductor wafers 1A, 1B and 1C are made of silicon single crystal and the surface 11 thereof is the (001) plane. Here, as shown in FIG. 3, for example, when the (115) plane 12A in the silicon single crystal is used as a reference for determining the direction of the semiconductor wafer 1B, the incident angle θ3 of the primary X-ray 5 on the surface 11 is θ3. From the wavelength of the primary X-ray 5 and the interplanar spacing d of the {115} planes 12 in the silicon single crystal, the incident angle θ1 of the primary X-rays 5A and the diffraction X of the {115} planes 12 on the {115} plane 12 The difference θ3 between the reflection angle θ1 of the line 7A and the angle θ2 formed by the surface (001) plane 11 and the {115} plane 12 of the semiconductor wafer 1B is set to 31.74 degrees in this case. Further, the detection angle θ4 of the diffracted X-ray 7A on the surface 11 is set to the sum θ4 of both the angles θ1 and θ2, in this case 63.33 degrees.

With this setting, the {115} plane 12
The diffracted X-ray 7A can be detected as shown in FIG. Here, the {115} plane 12 means the (115) plane 12A and a plane equivalent thereto, and since there are four planes in total, the same result is obtained in the detection result during one rotation of the semiconductor wafer 1B shown in FIG. Rotation angles ω1, ω2, ω3, which have four peaks of intensity I and are equally spaced,
Although it appears at .omega.4, for example, the first appearing peak at the rotation angle .omega.1 may be specified as that due to the (115) plane 12A. The specific crystal lattice plane (115) plane 12A in the semiconductor wafer 1B is specified by the control means 9 (FIG. 1) which receives the detection result of FIG. 4 from the detector 8 as a signal.

The predetermined crystal lattice plane 12A is {11
5} surface 12, the incident angle θ1 of the primary X-ray 5A and the reflection angle θ1 of the diffracted X-ray 7A on the surface 12A obtained from the Bragg's condition are as follows.
Surface (001) surface 11 of semiconductor wafers 1A, 1B, 1C
Any surface may be used as long as it is larger than the angle θ2 formed by the surface 12A.

When the surface 11 of the semiconductor wafer 1A, 1B, 1C is not the {001} plane, the semiconductor wafer 1A,
When 1B and 1C are made of a single crystal other than silicon, even if the primary X-ray 5A is not a Cu-Kα ray, the incident angle θ3 of the primary X-ray 5A on the surface 11 and the detection angle θ4 of the diffracted X-ray 7A. By appropriately setting in the same manner as described above, the specific crystal lattice plane in the semiconductor wafer 1B can be used as the predetermined crystal lattice plane 12A, and the diffracted X-ray 7A by the plane 12A can be detected. Viewed from the axis B, the semiconductor wafers 1A, 1B, 1
When the crystal lattice in C is asymmetric, it can be set so that the specific peak intensity I appears only once in the detection result, and a predetermined single crystal lattice from a plurality of equivalent planes 12 can be obtained. It is not necessary to specify the surface 12A.

Next, the specified crystal lattice plane, for example, the (115) plane 12A thus specified, has a predetermined positional relationship with the transport direction A, for example, as shown in FIG.
The rotation angle of the semiconductor wafer 1B, that is, the rotation angle of the rotation means 3 is controlled to ω1 by the control means 9 so that the diffracted X-rays 7A from the surface 12A enter the detector 8. The direction of the wafer 1B is determined.

After this determination, as shown in FIG. 1, the control means 9 controls the elevating means 4 to lower the rotating means 3 to the lower position where the semiconductor wafer 1B is placed on the transfer means 2A, 2B. Further, the transfer means 2A, 2B are controlled to transfer the semiconductor wafers 1A, 1B, 1C in the transfer direction A. Thereafter, similarly, the semiconductor wafer 1A and the semiconductor wafer subsequent thereto are sequentially oriented and transferred in the transfer direction A. As described above, according to the method of the first embodiment, the directions of the semiconductor wafers 1A, 1B, and 1C that are single crystals are determined by X-ray optics determination based on the crystal orientation, and thus the mechanical processing is performed. The area of the surface 11 of the semiconductor wafers 1A, 1B, and 1C does not decrease due to the marking by, and the area that can be used as a circuit board does not decrease. Therefore, the cost per chip formed on the semiconductor wafers 1A, 1B, 1C can be sufficiently reduced.

Next, the method of the second embodiment of the present invention will be described. In the method of the second embodiment, as shown in the side view of the main part of FIG. 5, the surface 11 of the semiconductor wafer 1B is irradiated with the primary X-rays 5B spreading in a fan shape on the paper from the X-ray source 6B, and is generated. Unlike the method of the first embodiment, the diffracted X-ray 7B is detected by the detector 8, and the other points are the same. That is, in the apparatus used, the X-ray source 6B is
For example, an X-ray tube 16 that is a point light source that radially generates X-rays
And a slit 17 having a linear hole 17a along the paper surface, which is different from the apparatus used in the method of the first embodiment, and is otherwise the same.

The X-ray source 6B is composed of an X-ray tube which is an elongated linear light source perpendicular to the paper surface of FIG. 5, a slit having an elongated rectangular hole along the X-ray tube, that is, perpendicular to the paper surface, and a so-called solar slit. Can also be used. That is, in this case, in order to limit the spread of the primary X-rays 5B in the direction perpendicular to the paper surface, a large number of foils (flat plates) parallel to the paper surface are provided on the traveling side of the primary X-rays 5B with respect to the slits. ) Is arranged at regular intervals with a solar slit.
The primary X-ray 5B is passed between the foils. Further, the primary X-ray 5B obtained in this case spreads in a fan shape on the paper surface and a plane parallel thereto.

The semiconductor wafers 1A, 1B and 1C have a front surface 1
In many cases, 1 is formed so as to be the (001) plane, but in some cases, it is intentionally made to be deviated by about 5 degrees from the (001) plane, and it is also formed so as to be the (001) plane. Inaccurate even if the semiconductor wafer 1A, 1
There may be a sled or the like on B and 1C. In such a case, if the device for irradiating the needle-shaped primary X-rays 5A is used as in the method of the first embodiment, it is possible to detect when the surface 11 is exactly the (001) plane. The predetermined crystal lattice plane (for example, {115} plane) 12 to be formed does not satisfy the Bragg condition, and the diffracted X-ray 7A may not be generated.

On the other hand, in the method of the second embodiment, the primary X having a fan shape having a spread of, for example, an apex angle of about 20 degrees.
Since the device that irradiates the line 5B is used,
The value of the incident angle θ1 of the secondary X-ray 5B has a spread, and one of the primary X-rays 5B has a predetermined crystal lattice plane {115} plane 1
By satisfying the condition of 2 and Bragg, the diffracted X-ray 7B can be generated and made incident on the detector 8. Therefore, according to the method of the second embodiment, a wider range of semiconductor wafers 1A, 1B and 1C with respect to the orientation of the surface 11 can be handled without changing the position setting of the X-ray source 6B in the apparatus used. Further, the position setting of the X-ray source 6B does not have to be performed so strictly.

In the method of the second embodiment, 1
Since the secondary X-ray 5B has a spread, the primary X to the crystal lattice plane
The value of the incident angle θ1 of the line 5B also has a spread, {115}
Diffraction X is also possible for the types of surfaces other than those that satisfy the Bragg condition.
The line 7B is generated, and the diffracted X-ray 7B is incident on the detector 8 and can be detected.

However, even if a plurality of types of crystal lattice planes including the {115} plane are detected, the number of equivalent planes in each crystal lattice plane appearing during one rotation of the semiconductor wafers 1A, 1B, 1C described above. That is, the type of the detected surface can be specifically known from the symmetry of each crystal lattice surface viewed from the axis B. Therefore, in the method of the second embodiment, the predetermined crystal lattice planes can be selected from other than the {115} planes, and a plurality of them can be set. In this case, by the control means 9, from the detection result of the detector 8,
For example, of the types of crystal lattice planes with the highest intensity I,
The one that appears first may be specified as the predetermined crystal lattice plane, and the semiconductor wafers 1A, 1B, and 1C may be moved in the carrying direction A based on the rotation angle at which the specified predetermined crystal lattice plane appears. Rotating means 3 so that a predetermined positional relationship can be obtained.
It is sufficient to control the rotation angle of.

Next, the method of the third embodiment of the present invention will be described. In the method of the third embodiment, as shown in the plan view of FIG. 6, the side surface 13 (also shown in FIG. 1) of the semiconductor wafer 1B rotated by the rotating means 3 is needle-shaped from the X-ray source 6A. Diffraction X generated by irradiating primary X-ray 5A
Unlike the method of the first embodiment in that the line 7A is detected,
Other points are the same. Note that the control unit 9 is not shown in FIG. 6 as well. Further, in the apparatus used in this method, the X-ray source 6A and the detector 8 are fixed to the floor via a support mechanism (not shown) at the same height as the rotating semiconductor wafer 1B in the raised position.

In the method of the second embodiment, if the semiconductor wafers 1A, 1B and 1C are made of silicon single crystal and the surface 11 is the (001) plane, the crystal lattice plane perpendicular to this is {220}. Plane, {400} plane, {440}
There are a lot of faces, such as {620} face, and these faces are
Rotating means 3 for rotating the semiconductor wafers 1A, 1B, 1C
Since they are parallel to the rotation axis B of, the both can be parallel to the transport direction A by rotation. So now, (44
When the (0) plane is a predetermined crystal lattice plane 14A used as a reference for determining the direction of the semiconductor wafer 1B, the incident angle of the primary X-ray 5 and the detection angle of the diffracted X-ray 7 on the side surface 13 are set to 1 Incident angle of the primary X-ray 5A on the {440} plane 14 obtained from the Bragg condition from the wavelength of the next X-ray 5, for example, Cu-Kα ray, and the plane spacing of the {440} plane 14 in the silicon single crystal. θ1 and reflection angle of diffracted X-ray 7A θ1
Same as above, but in this case set to 53.43 degrees.

With this setting, the {440} plane 14
The diffracted X-ray 7A can be detected in the same manner as in FIG. 4 shown in the method of the first embodiment. The subsequent procedure is the same as the method of the first embodiment. According to the method of the second embodiment, the first
In addition to the function and effect of the method of the embodiment, the side surface 13 of the semiconductor wafer 1B is irradiated with the needle-shaped primary X-ray 5A,
There is an effect that it can be applied even when there is no space for installing the X-ray source 6A and the detector 8 above the semiconductor wafer 1B. Further, when there is a space above the semiconductor wafer 1B whose direction should be determined, a suction means, a rotation means, and an elevating means are provided above the semiconductor wafer 1B, the semiconductor wafer 1B is adsorbed by the adsorbing means, and lifted by the elevating means. It is also possible to raise it to the position and then rotate it by the rotating means. In this case, the conveying means can be a single continuous means, and the structure of the apparatus used can be simplified.

Next, the method of the fourth embodiment of the present invention will be described. In the method of the fourth embodiment, as shown in the perspective view of the main part of FIG. 7, the primary radiation spread from the X-ray source 6C to the side surface 13 of the semiconductor wafer 1B on a plane parallel to the rotation axis B of the semiconductor wafer 1B. Diffracted X-rays 7C generated by irradiating X-rays 5C
Is different from the method of the third embodiment in that it is detected by the detector 8, and other points are the same. That is, in the apparatus used, the X-ray source 6C is, for example, the semiconductor wafer 1B.
Unlike the apparatus used in the method of the third embodiment, the X-ray tube 26, which is an elongated linear light source parallel to the rotation axis B, and the slit 17 having a linear hole 17a extending along the X-ray tube 26 are different from the apparatus used in the method of the third embodiment. It is the same. In this case, since the spread of the primary X-ray 5C on the plane parallel to the rotation axis B of the semiconductor wafer 1B is positively used, a solar slit or the like for limiting it is not used. In FIG. 7, for ease of illustration and understanding, the portion of the semiconductor wafer 1B on the front side of the crystal lattice plane 14 is removed, and the crystal lattice plane 14 is represented as a fractured surface.

Here, since the X-ray tube 26 as a line light source is, so to speak, a series of vertically arranged point light sources that generate X-rays in a radial pattern, the X-ray source 6C faces the semiconductor wafer 1B. The generated primary X-ray 5C spreads in a fan shape from one point as used in the method of the second embodiment 5B (FIG. 5).
Rather, it is a collection 5C of primary X-rays having various directions on a plane parallel to the rotation axis B of the semiconductor wafer 1B. Most of these pass through the top and bottom of the semiconductor wafer 1B or are reflected and absorbed on the front surface 11 or the back surface, but those within the range shown by the chain double-dashed line in FIG. 7 are the side surfaces 13 of the semiconductor wafer 1B. Is irradiated.

By the way, in the method of the third embodiment, the same problem as in the method of the first embodiment occurs. That is, the semiconductor wafers 1A, 1B, and 1C are often manufactured such that the surface 11 is the (001) plane, but in some cases, the semiconductor wafers 1A, 1B, and 1C are intentionally manufactured by being shifted by about 5 degrees from the (001) plane. In addition, it is not accurate even when it is manufactured to have the (001) plane, or the semiconductor wafers 1A, 1B, 1C
There may be a sledge. In such a case, if the device for irradiating the needle-shaped primary X-rays 5A is used as in the method of the third embodiment, the surface 11 is accurately (00
The predetermined crystal lattice plane (for example, {440} plane) 14 to be detected in the case of the 1) plane does not satisfy the Bragg condition, and the diffracted X-ray 7A may not be generated.

On the other hand, in the method of the fourth embodiment, the side surface 13 of the semiconductor wafer 1B has a certain angle range on the surface parallel to the rotation axis B of the semiconductor wafer 1B.
Since a device for irradiating the next X-ray 5C is used, the crystal lattice plane 1
4 is not exactly parallel to the rotation axis B of the semiconductor wafer 1B (even if it is not perpendicular to the surface 11 of the semiconductor wafer 1B),
Primary X-ray 5C irradiated on the side surface 13 of the semiconductor wafer 1B
Any of (in the range indicated by a chain double-dashed line in FIG. 7) satisfies a predetermined crystal lattice plane {440} plane 14 and Bragg's condition to generate a diffracted X-ray 7C, and a detector 8
Can be incident on. Therefore, according to the method of the fourth embodiment, a wider range of semiconductor wafers 1A, 1B, 1C with respect to the orientation of the surface 11 can be handled without changing the position setting of the X-ray source 6C in the apparatus used. Also, X
The position of the radiation source 6C need not be set so strictly. The measures to be taken when a plurality of types of crystal lattice planes are detected are the same as in the method of the second embodiment.

Conventionally, when a semiconductor wafer is cut out from an ingot, the direction in which it is to be cut is usually such that the bottom surface at one end of a substantially cylindrical ingot is first cut out and the bottom surface is irradiated with primary X-rays. As in the method of the third embodiment, it is possible to irradiate the side surface of the ingot rotating around the central axis of the cylinder with a needle-shaped primary X-ray to perform the investigation. Further, as in the method of the fourth embodiment, it is possible to use an X-ray source including an X-ray tube which is an elongated linear light source parallel to the rotation axis and a slit having a linear hole extending along the X-ray tube. However, when the ingot is irradiated with the primary X-rays having a spread on a plane parallel to the rotation axis, unlike the method of the fourth embodiment, the side surface of the thin semiconductor wafer is irradiated with an unnecessarily large number of types. There is a possibility that the Bragg's condition will be satisfied and detected for the crystal lattice plane of. Therefore, in this case, a solar slit in which a large number of foils (flat plates) perpendicular to the rotation axis are arranged at appropriate constant intervals on the side of the primary X-ray traveling direction with respect to the slits is arranged between the foils. By passing the primary X-ray, the spread on a plane parallel to the rotation axis is appropriately limited.

[Brief description of drawings]

FIG. 1 is a side view showing an apparatus used in a semiconductor wafer orientation determining method according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the device.

FIG. 3 is a side view showing setting of an incident angle of primary X-rays and a detection angle of diffracted X-rays on the surface of a semiconductor wafer in the method of the first embodiment.

FIG. 4 is a diagram showing a detection result of diffracted X-rays in the method of the first embodiment.

FIG. 5 is a side view showing a main part of an apparatus used in a semiconductor wafer orientation determining method according to a second embodiment of the present invention.

FIG. 6 is a plan view showing an apparatus used for a semiconductor wafer orientation determination method according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing a main part of an apparatus used in a semiconductor wafer orientation determining method according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view showing an ingot having an orientation flat which is a base material of a conventional semiconductor wafer.

FIG. 9 is a perspective view showing a semiconductor wafer having a conventional orientation flat.

[Explanation of symbols]

1A, 1B, 1C ... Semiconductor wafer, 2A, 2B ... Conveying means, 3 ... Rotating means, 5A, 5B, 5C ... Primary X-ray, 6
A, 6B, 6C ... X-ray source, 7A, 7B, 7C ... Diffraction X
Lines, 8 ... Detectors, 9 ... Control means, 11 ... Semiconductor wafer surface, 12A, 14A ... Predetermined crystal lattice planes, 13 ... Semiconductor wafer side surfaces, A ... Transport direction, B ... Vertical to semiconductor wafer surface Axis of rotation.

Claims (4)

[Claims] 1. A disk-shaped semiconductor wafer is transferred, the semiconductor wafer is rotated about an axis perpendicular to the surface in the transfer path, and the surface of the rotated semiconductor wafer is subjected to primary X-rays. Of the semiconductor wafer to detect diffracted X-rays, and from the detection result, identify a predetermined crystal lattice plane in the semiconductor wafer. The identified crystal lattice plane has a predetermined positional relationship with the transport direction. Method for controlling the orientation of a semiconductor wafer so as to control the rotation of the semiconductor wafer. 2. A disk-shaped semiconductor wafer is transferred, and in the transfer path, the semiconductor wafer is rotated about an axis perpendicular to its surface, and a primary X-ray is emitted to the side surface of the rotated semiconductor wafer. Of the semiconductor wafer to detect diffracted X-rays, and from the detection result, identify a predetermined crystal lattice plane in the semiconductor wafer. The identified crystal lattice plane has a predetermined positional relationship with the transport direction. Method for controlling the orientation of a semiconductor wafer so as to control the rotation of the semiconductor wafer. 3. A transfer means for transferring a disk-shaped semiconductor wafer, a rotating means provided in a transfer path of the transfer means for rotating the semiconductor wafer around an axis perpendicular to the surface thereof, and the rotating means. An X-ray source for irradiating the surface of a rotated semiconductor wafer with primary X-rays, a detector for detecting diffracted X-rays generated from the semiconductor wafer for irradiation with the primary X-rays, and a detector thereof And a control means for controlling the rotating means so that the specified crystal lattice plane in the semiconductor wafer is specified based on the detection result and the specified crystal lattice surface has a predetermined positional relationship with the carrying direction of the carrying means. Semiconductor wafer orientation determining device. 4. A transfer means for transferring a disc-shaped semiconductor wafer, a rotating means provided in a transfer path of the transfer means for rotating the semiconductor wafer around an axis perpendicular to the surface thereof, and the rotating means. An X-ray source for irradiating a side surface of a rotated semiconductor wafer with a primary X-ray, a detector for detecting a diffracted X-ray generated from the semiconductor wafer for which the primary X-ray is irradiated, and a detector therefor. And a control means for controlling the rotating means so that the specified crystal lattice plane in the semiconductor wafer is specified based on the detection result and the specified crystal lattice surface has a predetermined positional relationship with the carrying direction of the carrying means. Semiconductor wafer orientation determining device.