JP3254274B2 - X-ray single crystal orientation measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray single crystal orientation measuring apparatus for measuring a relative position of a groove with respect to a crystal axis direction inside a single crystal in a single crystal sample having a groove for confirming a crystal orientation. .

[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 a single crystal of Si (silicon). As is well known, a single crystal is a substance in which the direction of the atomic arrangement inside the crystal, that is, the direction of the crystal axis, is completely aligned over the entire crystal. The direction of the crystal axis is usually called an orientation, and in the above-described IC manufacturing process, the process is performed in a state where the crystal orientation of a plurality of Si wafers to be processed is always oriented in a fixed direction. It must be.

Conventionally, in order to know the crystal orientation of a Si wafer, an orientation flat, a flat portion commonly called an orientation flat, is formed at a certain position with respect to the crystal orientation, and the orientation flat is formed when performing an IC manufacturing process. Various processes are performed on the basis of. In order to manufacture a certain high quality IC, the orientation flat surface must be Si
It must be accurately formed at a predetermined reference position with respect to the crystal orientation inside the wafer.

Conventionally, as an apparatus for inspecting whether an orientation flat surface is formed at an accurate position with respect to a crystal orientation in a Si wafer, an apparatus using X-rays as shown in FIG. 5 is widely known. ing. In this apparatus, a thin disk-shaped Si wafer 1 having an orientation flat surface 2 on a part of the outer peripheral side surface is placed on a table 3. The orientation flat surface 2 is pressed against two reference plates 4, 4 fixed to the side surface of the table 3, and receives the X-ray R <b> 1 in a stationary state. The X-ray R1 incident on the orientation flat surface 2 is diffracted on the crystal lattice plane inside the wafer 1, and is emitted from the wafer 1 as a diffraction line R2.

If the orientation flat surface 2 is formed at a regular position with respect to the crystal orientation, a diffraction line R2 is detected by an X-ray counter (not shown) placed at a predetermined angle position. On the other hand, if the orientation flat surface 2 is shifted from the normal position,
The diffraction line R2 cannot be detected unless the X-ray counter is angularly displaced by an angle corresponding to the angular deviation. As described above, the orientation flat surface is determined by whether or not the diffraction line R2 from the wafer 1 can be detected by the X-ray counter, or by measuring the angular deviation from the normal position of the X-ray counter when the diffraction line R2 is detected. 2 is determined.

[0006]

In recent years, instead of using a wide notch like an orientation flat surface, a very narrow notch such as a small V-shaped groove has been used. An orientation determination method for checking the crystal orientation inside the wafer has been considered. When such a V-shaped groove is used, measurement cannot be performed using an azimuth measuring device as shown in FIG. 5, and some measures have been demanded.

SUMMARY OF THE INVENTION The present invention has been made in order to meet the demand, and relates to a single crystal sample of a type using a V-shaped groove as a criterion for determining a crystal orientation. It is an object of the present invention to provide an X-ray single crystal orientation measuring apparatus capable of reliably measuring the position of X-ray single crystal.

[0008]

An X-ray single crystal orientation measuring apparatus according to the present invention determines the relative position of the above-mentioned groove with respect to the crystal axis orientation inside the single crystal with respect to a single crystal sample having a groove for confirming the orientation. An X-ray single crystal orientation measuring apparatus for measuring, comprising: an X-ray source for irradiating an X-ray toward a single crystal sample; and an X-ray detector for detecting a diffraction line diffracted by the single crystal sample. In a single crystal orientation measuring apparatus, two guide members abutting on the outer peripheral surface of a single crystal sample, a fitting member arranged on a perpendicular bisector about a line connecting the two guide members, and a fitting member thereof and resilient biasing means for resiliently biasing the coupling member in a direction toward the two guide members, said two guide
Between the member and the fitting member so that it can be moved in parallel in two axial directions.
And a slide table on which the single crystal sample is placed .

[0009]

The single crystal sample to be measured is fixedly held at a fixed position by a stationary holding mechanism constituted by a guide member, a fitting member and elastic biasing means. At this time, the orientation confirmation groove of the single crystal sample is always positioned at a fixed position while being fitted to the fitting member. The X-ray measurement system having the X-ray source and the X-ray detector is fixedly arranged at a fixed position with respect to the sample holding mechanism, and has an internal crystal orientation with respect to the single crystal sample held stationary as described above. Measurement.

[0010]

FIG. 1 shows a reference example of an X-ray single crystal orientation measuring apparatus according to the present invention. The measuring device includes a base plate 6 fixed on a support 5, a slide table 7 mounted on the base plate 6 and slidably movable in the direction of arrow AA, and fixed on the slide table 7. And a sample table 8 having a polygonal shape. A linear fine movement mechanism such as a micrometer head 9 is disposed at the tip of the slide table 7, and the slider 9 a of the micrometer head 9 is in contact with the tip of the slide table 7.

A rectangular groove 10 is formed in the center of the sample table 8, and two guide rods 11, 11 are provided in the groove 10. These guide rods 1
1, another slider 13 elastically biased toward the center of the sample table 8 by the slider 12 and the compression spring 23.
However, both are provided so as to be slidable. A lever 14 is attached to the slider 12 so as to be rotatable about a support shaft 15. A pin 17 fixed to the other slider 13 and protruding upward is fitted into an elongated hole 16 formed at the tip of the lever 14. are doing.

On the slider 13, a fitting pin 18 for wafer positioning is fixedly provided. Further, two guide rollers 19, 19 are rotatably fixed to the sample table 8 at a portion opposite to the fitting pins 18 by screws 20. The fitting pin 18 is set so as to be positioned on a vertical bisector L2 of a line L1 connecting the guide rollers 19 with respect to the two guide rollers 19,19.

An X-ray source 21 and an X-ray source 21
An X-ray measurement system having an X-ray counter 22 is provided as a line detector.

Since the X-ray single crystal orientation measuring apparatus of this embodiment is constructed as described above, the Si wafer 24 to be measured having the V-shaped groove 25 as shown in FIG. Is placed on the sample stage 8 as described above. At this time, the fitting pins 18 are fitted into the V grooves 25, and the wafer 24 is pressed against the two guide rollers 19 by the spring force of the spring 23. Thus, the wafer 24 is supported at three points by the two guide rollers 19 and the fitting pins 18, and the V groove 25
Is always positioned at a fixed position on the basis of.

An X-ray R1 is emitted from the X-ray source 21 to the wafer 24 positioned in this manner, and is incident on the outer peripheral surface of the wafer 24. The incident X-rays are diffracted on the crystal lattice plane inside the wafer 24 and are emitted as diffraction lines R2 from the wafer 24. The diffraction line R2 is detected by the X-ray counter 22. With respect to the wafer 24, if the crystal orientation in the wafer 24 is oriented in the normal direction with respect to the V-groove 25, the X-ray counter 22 determines that the diffraction line R2
Is detected. On the other hand, if the internal crystal orientation deviates from the reference position with respect to the V-groove 25, an angle shift occurs in θ accordingly. By measuring the angle shift, the shift of the internal crystal orientation of the wafer 24 is measured.

The micrometer head 9 precisely moves the outer peripheral surface of the wafer 24 on the X-ray optical path by slightly moving the slider rod 9a straight forward. A plurality of circular recesses 2 are provided along the circular locus centered on the center point of the sample table 8 at the fixed position of the guide roller 19 on the sample table 8.
6 are provided. These are concave portions for mounting the guide rollers 19, and by selecting an appropriate one of these, and mounting the guide rollers 19 thereon, it is possible to perform azimuth measurement on wafers 24 having different sizes. it can.

FIG. 2 shows an embodiment of the X-ray single crystal orientation measuring apparatus according to the present invention. This embodiment is different from the reference example shown in FIG. 1 in that the measurement target is not the wafer 24 but the Si single crystal ingot 27 itself before forming the wafer. In FIG. 2, the same members as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

This measuring apparatus comprises a slide table 28 which can be freely translated in two X-axis directions orthogonal to each other.
And a rotary table 29 provided on the XY slide table 28 so as to be rotatable about an axis ω. On the right side of the XY slide table 28, a wedge-shaped fitting member 31 supported by a stand 30 is provided. As shown in FIG. 3, the wedge-shaped fitting member 31 is
8 is elastically urged. The stand 30
While being guided by the guide plate 33 extending from the support column 5, it moves straight as indicated by the arrow BB. In this device, the wedge-shaped fitting member 31 is located on a vertical bisector L2 of a line L1 connecting the two guide rollers 19, as shown in FIG.

In this apparatus, the measurement is performed as follows.

First, an Si single crystal ingot 27 to be measured is placed on a rotary table 29. The ingot 27 is formed with a V-shaped groove 25 for confirming the direction of the crystal orientation inside the ingot 27 in the axial direction. The ingot 27 is merely placed on the turntable 29, and no measures are taken to fix it.

Next, the wedge-shaped fitting member 31 is fitted into the V-groove 25, and the stand 30 is further pushed to move the ingot 27 toward the guide rollers 19,19. At this time, the ingot 27 is moved in parallel in two directions of X and Y by the function of the XY slide table 28, and is appropriately rotated around the axis ω by the function of the rotary table 29, and is moved to both the two guide rollers 19. It is set at a fixed position where it abuts. In this state, the X-ray R1 emitted from the X-ray source 21 is incident on the outer peripheral side surface of the ingot 27, and the diffraction line R2 is detected by the X-ray counter 22.

Also in this device, the ingot 27
Since it is supported at three points by the two guide rollers 19 and the wedge-shaped fitting member 31, it is always arranged at a fixed position with respect to the V groove 25.

According to the apparatus of the present embodiment, the XY slide table 28 and the rotary table 29 allow the ingot 2
Since the ingot 27 is carried to the predetermined three-point support position while freely moving the 7, the extremely heavy ingot 27 can be set to the predetermined measurement position very easily.

[0024]

According to the present invention, the position of the V-shaped groove with respect to the crystal orientation in the sample can be reliably determined using X-rays for a single crystal sample of the type using a V-shaped groove as a criterion for determining the crystal orientation. Can be measured.

[0025]

[Brief description of the drawings]

FIG. 1 is a reference example of an X-ray single crystal orientation measuring apparatus according to the present invention.
Is a perspective view showing a.

2 is a perspective view showing a Kazumi施例of X-ray single crystal orientation measuring apparatus according to the present invention.

FIG. 3 is a plan view of the X-ray single crystal orientation measuring apparatus shown in FIG.

FIG. 4 is a perspective view showing a Si wafer as an example of a single crystal sample to be measured.

FIG. 5 is a perspective view showing a conventional azimuth measuring device using an orientation flat surface.

[Explanation of symbols]

 Reference Signs List 18 fitting pin (fitting member) 19 guide roller (guide member) 21 X-ray source 22 X-ray counter (X-ray detector) 23 compression spring 24 Si wafer 25 V-shaped groove 27 Si single crystal ingot 28 XY slide table 29 rotary table 31 wedge-shaped fitting member 32 compression spring L1 line segment connecting both guide members L2 vertical bisector

Claims (2)

(57) [Claims] An X-ray single crystal orientation measuring apparatus for measuring a relative position of the above-mentioned groove with respect to a crystal axis direction inside a single crystal with respect to a single crystal sample provided with a groove for confirming an orientation. X-ray source provided with an X-ray source for irradiating X-rays toward the target and an X-ray detector for detecting a diffraction line diffracted by the single crystal sample
In the linear single crystal orientation measuring device, two guide members abutting on the outer peripheral surface of the single crystal sample, and a fitting member arranged on a perpendicular bisector about a line connecting the two guide members, An elastic urging means for elastically urging the fitting member in a direction toward the two guide members, and a biaxial direction between the two guide members and the fitting member.
To move a single crystal sample.
An X-ray single crystal orientation measuring device comprising a ride table . 2. The X-ray single crystal orientation measuring apparatus according to claim 1, wherein a rotary table on which the single crystal sample is rotatably mounted is provided on the slide table.