JPH074110Y2 - Polishing jig - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a semiconductor single crystal processing tool used in the semiconductor industry, and more particularly to a polishing tool for polishing a specific azimuth plane of a single crystal.

[Prior art]

The physical or chemical properties of semiconductor single crystals have anisotropy, and it is an important step in the fabrication of electronic devices and optical elements to process the single crystal into a specific orientation plane to bring out the desired properties. one of. As a method of processing the above-mentioned specific azimuth plane of a single crystal, generally, a method of repeatedly cutting and polishing while measuring the plane orientation of the crystal with an X-ray diffractometer to finally obtain a single crystal having a predetermined azimuth plane Target.
The first method is a method of cutting with a wire saw or an inner peripheral blade type cutting machine or the like according to a target plane orientation by an X-ray diffractometer, but it is difficult to obtain a desired azimuth plane by cutting once. It was often the case that the desired crystallographic orientation plane was obtained only after repeating cutting while making several corrections.
In the case of a large crystal such as quartz, even if the crystal is wasted to some extent, it is possible to obtain a work piece having a azimuth plane of considerably high accuracy by this method, but it is difficult to grow the large crystal. Alternatively, in the case of a crystal having an indefinite shape, if the above processing method is applied, the orientation accuracy of about 0.5 to 1.0 ° can be obtained with one cutting. For such a crystal whose plane orientation is deviated, the plane orientation is corrected and polished by using a correction jig as shown in FIG. 7 in combination with an X-ray diffractometer at the time of lapping. (Rev., Sci., Instrum., 48, 1215 (1977)). The plane orientation correction jig 20 shown in FIG. 6 has a shaft 22 arranged inside a cylinder 21, and the shaft 22 is composed of a plurality of angle adjusting screws 23 and stopper screws 25 provided on the upper and lower peripheral sides of the cylinder 21. It is movably supported in the cylinder 21 in the radial direction of the cylinder and the axial direction of the cylinder. A piston 26 is inserted into the shaft 22, and the end of the piston 26 faces the polishing side end of the cylinder 21, and the end holds a crystal sample.
27 is installed. A pressure adjusting screw 29 for adjusting the load on the sample holder 27 during crystal polishing is attached to the side of the shaft 22 opposite to the side where the piston 26 is fitted. Therefore, the crystal on the sample holder 27 protruding from the plane formed by the end of the iron ring 30 at the lower end of the cylinder 21 can be polished (not shown) until it is flush with the plane forming the iron ring 30. The diffractometer method or the back surface Laue method is known as a method for correcting the crystal plane orientation by combining such a plane orientation correction jig and an X-ray diffractometer. The diffractometer method is as shown in FIG.
The surface orientation jig 20 is rotatably mounted on the block 31, the X-ray from the X-ray irradiator 41 is applied to the sample 32 on the surface orientation jig 20, and the surface orientation jig 20 is rotated. This is a method in which the target azimuth plane is obtained by detecting the reflected light with the detector 42. In addition, as shown in FIG. 8, the back surface Laue method is a V block.
The X-ray 33 is irradiated onto the sample 32 through the pinhole collimator 34 from a direction orthogonal to the end surface of the sample 32 supported by the surface orientation correcting jig 20 on the surface 31 and the diffraction spots of the reflected X-ray are pinholes. The angle adjusting screw 23 of the plane orientation correcting jig 20 is adjusted so that the position "X" on the photosensitive film 36 arranged on the plane orthogonal to the collimator 34 is aligned with the passing position of the incident X-ray 33 on the film 36. This is a method of finding the crystal orientation plane to be obtained.

[Issues to be solved by the device]

However, the above-described conventional crystal plane orientation correction method has many problems. That is, in order to use the diffractometer method, it is necessary to incorporate a complicated and highly accurate precision machine-rotatable plane orientation correction jig, such as an X-ray diffractometer, and the X-ray diffractometer requires a large amount of space. It is forced to be remodeled. Further, since the back surface Laue method corrects the crystal plane orientation on a member independent of the X-ray diffractometer, the back Laue method does not require a major modification of the X-ray diffractometer itself. Measurement can be performed with a device simpler than that of the fractometer method, but still, it is necessary to connect the plane orientation correction jig to the X-ray diffractometer, and the connection method must be highly accurate. The azimuth measurement accuracy by the back Laue method depends on the layout of the Laue camera, the accuracy of the V block, etc., and the azimuth measurement error is limited to about 0.5 °. However, in the current semiconductor manufacturing technology, this azimuth measurement error is
It is required to be kept within 0.1 °, and it can be said that the current back surface Laue method is hardly applicable. In addition, even if the deviation of the plane orientation is known, it is necessary to correct it under X-ray irradiation, and it is impossible to quantitatively correct the deviation of the plane orientation by the angle adjusting screw alone of the plane orientation correction jig. There were also drawbacks. Therefore, the present invention solves the above-mentioned problems of the prior art and eliminates the need to connect the plane orientation correction jig to the X-ray diffraction apparatus. Therefore, when the plane orientation correction jig and the X-ray diffraction apparatus are connected, It is an object of the present invention to provide a polishing jig having a relatively simple structure while eliminating the measurement error that occurs in step (1) and eliminating the hassle of measuring with X-rays in a state in which both are connected.

[Means for Solving the Problems]

The above object of the present invention is to provide a polishing jig rotary holder with a central through hole in the up-and-down direction, and dispose a slidable piston in the through hole. One end of the piston is provided on the polishing side surface of the polishing jig rotary holder. A goniometer capable of holding a crystal to be polished is attached to the part, and the piston is supported by the polishing jig rotary holder via the elastic member on the other end side of the piston extending from the polishing jig rotary holder. The polishing jig is characterized in that an elastic member holder capable of adjusting the elastic force of the elastic member is attached.

[Action]

In advance, measure the deviation of the crystal plane orientation with an X-ray diffractometer,
This crystal is set at the lower end of the goniometer of the present polishing jig, and the inclination of the plane orientation is corrected by the goniometer. After that, the surface of the crystal whose plane orientation is corrected is polished by a polishing machine (not shown).

【Example】

FIG. 1 shows a sectional view of an embodiment of the polishing jig of the present invention.
A piston 3 is arranged in a through hole 2 in the center of the polishing jig rotary holder 1 so as to be vertically slidable. A central shaft body 5 is provided at an upper end portion of the piston 3 so as to extend from the polishing jig rotation holder. A disk-shaped spring holder 6 is screwed onto the central shaft body 5, and a stopper screw 7 is also screwed onto the spring holder 6. Further, a weight 9 having an appropriate weight can be inserted into and removed from the central shaft body 5. The spring holder 6 and the polishing jig rotation holder 1 are connected via a spring 10. The spring 10 is an example of the elastic member of the present invention,
A combination of the spring holder 6, the stopper screw 7 and the weight 9 is an example of the elastic member holder of the present invention. Further, since the elastic force of the spring 10 can be adjusted by adjusting the moving distance of the spring holder 6 and the stopper screw 7 in the axial direction of the central shaft body 5, the combination of the spring holder 6 and the stopper screw 7 can be adjusted. Makes the resilience of the spring 10 adjustable. On the other hand, the goniometers 12 and 13 are fixed to the lower end of the piston 3 and inside the leg 11 of the polishing jig rotary holder 1. The goniometers 12 and 13 are a combination of goniometers capable of adjusting inclinations in directions orthogonal to each other, as shown in the detailed view of FIG. That is, the goniometer 12 can be rotated in the direction of arrow (a) by rotating the tilt adjusting screw 15 as shown in FIG. 2 (a), and the goniometer 13 can be tilted as shown in FIG. 2 (b). By rotating the screw 16, it becomes possible to rotate in the arrow (B) direction. FIG. 2 (c) is a plan view of an essential part of the polishing jig of the present invention seen from below. On the sample holder 17, a crystal sample 19 whose plane orientation shift has been measured by an X-ray diffractometer (not shown) in advance is attached via wax. Further, FIG. 3 shows a sectional inclination view of the polishing jig rotary holder 1, in which the crystals on the sample holder are slightly projected from the plane formed by the legs 11 of the polishing jig rotary holder 1. Is adjusted by the weight 9. Next, the ZnSe single crystal grown by the iodine transport method is taken as an example,
How to use this polishing jig will be explained. ZnSe single crystal, which is a II-VI group compound semiconductor crystal, is grown by the iodine transport method, cut with a wire saw, and has a single crystal substrate with an off-orientation plane having an off angle of several degrees with respect to the (100) plane. Was produced. The plane orientations of the off-orientation surface in the horizontal direction and the vertical direction were measured by an X-ray diffractometer to determine the deviation from the normal plane orientation. In order to keep the plane orientation accuracy when bonding the crystal plane whose plane orientation was measured to the sample holder 17, use the minimum amount of glycol phthalate sample mounting wax as much as possible in the sample holder 17 while paying attention to the horizontal and vertical directions of the crystal. Glued Then, the sample holder 17 is attached to the goniometer 12 which is the sample bonding portion while paying attention to the horizontal and vertical directions of the crystal, and the goniometers 12, 1
The horizontal and vertical tilts of 3 were corrected by polishing so that an accurate (100) plane was formed. After that, the crystal plane and the polishing jig rotary holder 1 are subjected to the following operations.
The bottom surface of the was matched and an appropriate polishing load was obtained. By rotating the spring holder 6 and moving it up and down, the spring is adjusted to adjust the load, and after adjustment, the stopper screw 7 fixes the position of the spring holder 6 on the central shaft body 5. Then
A weight 9 was inserted into the central shaft body 5 so that a load suitable for polishing the crystal plane, usually about 100 g / cm ² was applied. After such preparation is completed, the lower end surface of the crystal sample has a grain size of 3
After polishing with a diamond abrasive grain of μm, the plane orientation of the polished surface was measured again. A small polishing machine was used as the polishing machine (not shown). As shown in FIG. 3, a polishing jig rotary holder 1 having a groove 15 was used so that the abrasive grains spread to the entire surface of the platen uniformly to some extent during polishing. FIG. 4 is a result of examining the accuracy of the plane orientation correction jig with respect to the horizontal direction of the sample, and shows the relationship between the correction angle of the goniometer and the actually corrected angle. The first-order correlation was established, and the error with the target angle was within 0.2 °. FIG. 5 shows the results of examining the accuracy of the plane orientation correction jig in the vertical direction of the sample, and shows the relationship between the correction angle of the goniometer and the actually corrected angle. Similarly, a first-order correlation was established and the error with the target angle was within 0.3 °. Even if the horizontal and vertical inclinations of the goniometer, which is the sample adhesion part, are corrected at the same time and the surface orientation correction jig is used for polishing, the error is within 0.3 °. It turns out that it is possible to correct the plane orientation.

[Effect of device]

According to the present invention, a method for correcting a group IV, III-V, or II-VI semiconductor single crystal at the polishing stage using a polishing jig with a goniometer that can control the inclination in the horizontal and vertical directions is provided. By adopting this, it is not necessary to connect it to the X-ray diffractometer, and it is possible to quantitatively correct the plane orientation by the goniometer alone installed in the sample adhesion portion and to perform processing to a predetermined orientation plane with high accuracy. According to the present invention, in particular, it is possible to accurately process the II-VI group semiconductor single crystal plane orientation, which has been difficult in the past.

[Brief description of drawings]

FIG. 1 is a sectional view of a polishing jig used in the surface orientation correction method of the present invention, FIGS. 2 (a) and 2 (b) are partially enlarged side views of the polishing jig of the present invention, and FIG. FIG. 3 is a cross-sectional perspective view of the main part of the polishing jig rotary holder 1, and FIG. 4 is a schematic view of a plane orientation correction jig with respect to the horizontal direction when polishing is performed using the plane orientation correction method of the present invention. FIG. 5 shows the relationship between the corrected angle of the goniometer and the actually corrected angle, and FIG. 5 shows the corrected angle of the goniometer of the plane direction correction jig and the actual direction when the plane direction correction method of the present invention is used for polishing. FIG. 6 is a perspective view of a plane orientation correcting jig used in a conventional plane orientation correcting method, and FIG. 7 is a schematic view of an orientation measuring apparatus using a diffractometer method. Figure, 8th
Each of the figures shows a schematic view of an azimuth measuring apparatus using the Backlaue method.

Claims (1)

[Scope of utility model registration request] 1. A polishing jig rotary holder is provided with a central through hole in the vertical direction, and a slidable piston is arranged in the through hole, and one end of the piston is provided on a polishing side surface of the polishing jig rotary holder. A goniometer capable of holding a crystal to be polished is attached to the other end of the piston extending from the polishing jig rotary holder, and the piston is supported by the polishing jig rotary holder via an elastic member, and A polishing jig equipped with an elastic member holder capable of adjusting the elastic force of the elastic member.