JPS6237633Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field of the invention The invention relates to an angle polishing jig for thin pieces, and is particularly suitable for lap polishing a semiconductor wafer used in the manufacture of semiconductor devices by tilting it at a desired angle. This invention relates to improvements to angle polishing jigs.

(b) Prior art and problems Wafers made of semiconductor crystals that form semiconductor devices need to have smooth and extremely clean surfaces, and more importantly, the main surface of the wafer is exactly the desired crystal plane, i.e., the crystal-specific crystal plane expressed by the Miller index based on the crystal axis of the semiconductor crystal, for example (100),
It is necessary to slice the (110) or (111) plane, or in some cases, the (100) plane tilted several degrees in the direction of the (110) plane. This necessity is due to the fact that if the main surface of a crystal wafer deviates from the desired crystal plane even by a slight angle, the crystal layer will not be smooth when grown on such a wafer surface by, for example, epitaxial growth. There are disadvantages in that it is difficult to obtain a crystal growth surface or a high-quality crystal layer, and the electrical characteristics of the crystal growth layer are different from those predicted.

Therefore, in the past, the main surface of a wafer made by slicing an ingot made of semiconductor crystal was
For example, if the main surface of the wafer is measured in advance using an X-ray diffraction device or the like and deviates from a predetermined crystal plane by several degrees, the wafer 1 whose crystal plane is deviated as shown in FIG. A column-shaped fixing tool 2 whose one end surface has a desired inclination angle is pasted on the fixing surface 3 of the columnar fixing tool 2 with its deviation direction corresponding to that of the fixing tool 2, and the fixing tool 2 is inserted into and removed from the guide reference tube 4 as shown in the figure. While freely sliding together, the fixing tool 2 is supported by a screw 5 so as to be movable up and down, and the polishing jig is placed on a predetermined lap board 6 using an abrasive and is operated by sliding. , the main surface of the wafer 1 was polished to a desired crystal plane.

However, the main surface of wafer 1 does not always deviate from a predetermined crystal plane at a constant angle, and multiple wafers have deviations at various angles. In order to polish the main surface of the wafer to a desired crystal plane using the polishing jig described above, it is necessary to prepare several types of fixing tools with different angles of inclination of the wafer fixing surface. The problem was that the handling and management became complicated. In reality, it is not possible to prepare multiple types of fixing devices that can handle all wafers with different angles of misalignment, so in such a case, a wafer with an inclination angle that can approximately handle the wafer is used. There was also an inconvenience that had to be satisfied by using a fixing tool having a fixing surface in combination with the guide reference tube 4.

(c) Purpose of the invention The present invention eliminates the above-mentioned drawbacks of the conventional technology, and while the wafer to be polished to a desired crystal plane is fixed to the fixed surface of the polishing jig, the wafer is polished in the X-axis direction from the reference plane of the crystal of the wafer. Not only can it be polished so that the surface is tilted at any angle in the direction of the Y-axis, but it can also be easily adjusted so that the surface is tilted at any angle in the Y-axis direction from the reference surface. It is an object of the present invention to provide a novel angle polishing jig that can perform lap polishing on a desired crystal plane accurately.

(d) Structure of the device A reference outer cylinder 21 having a flat reference end face, an adjustment holding cylinder 26 that slides into and out of the reference outer cylinder 21, and an adjustment holding cylinder 26 that is included in the adjustment holding cylinder 26 so as to be tiltable. , is provided with a fixing table 24 which has a surface for fixing the object to be polished on one flat surface obtained by cutting a sphere into two parallel planes, and engages with the other flat surface of the fixing table 25 to make the slope of the fixing table 2.
At least three angle adjustment screws 29a, 29b, 29c for adjusting in the dimensional direction, and a plurality of locking screws 3 for fixing the fixing base after adjusting the angle of the fixing base.
This can be achieved by providing an angle polishing jig characterized in that the adjustment holding cylinder 26 is provided with the adjustment holding cylinder 26.

(e) Embodiments of the invention Preferred embodiments of the invention will be described in detail below with reference to the drawings.

FIG. 2 is a cross-sectional view of a main part of an embodiment of the angle polishing jig according to the present invention, and FIG. 3 is a cross-sectional view taken along the -' cutting line shown in FIG. 2. As is clear from these figures, one end of the 21 is open and has a flat reference end surface 22 that contacts the flat lapping plate 33, and the other end is closed leaving a screw hole 23. This is a reference outer cylinder made of wear-resistant metal. On the other hand, the fixing table 24 (hereinafter referred to as wafer fixing table) to which the crystal wafer 34 to be polished is attached has a wafer fixing surface 25 with at least one flat end surface, as shown in the figure, and its outer peripheral surface is spherical. In this embodiment, the wafer fixing table 24 is inserted into the cylinder 27 through a through screw hole 28 provided in the closed wall of the cylinder 27, which has one end open and the other end closed. Three angle adjustment screws 29a, 29b and 29c are disposed so as to be freely threadable, and a locking screw is provided so as to protrude by being screwed into the cylindrical body 27 from three sides of a predetermined outer peripheral portion of the cylindrical body 27. 30a, 3
0b and 30c are inserted into the adjustment holding cylinder 26, as shown in the figure, so that it can be freely tilted on its outer circumferential surface.

In order to lap polish the main surface of the crystal wafer 34 using the angle polishing jig having the above-described configuration by setting the polishing angle so that the desired crystal plane is obtained,
First, the crystal wafer 34 is placed on the wafer fixing surface 25 of the wafer fixing table 24 installed inside the adjustment holding cylinder 26.
After fixing the crystal wafer 34 with wax or the like, the adjustment holding cylinder 26 to which the crystal wafer 34 is fixed is attached to, for example, an X-ray diffraction apparatus (not shown), and the wafer 3
While measuring the crystal plane of 4, the three angle adjusting screws 29a, 29b and
9c is brought into contact with the back surface of the wafer fixing table 24, and by screwing it in and out, the fixing table 24 is tilted and adjusted so that the desired crystal plane is obtained, and the polishing angle θ of the wafer 34 is determined as shown in the figure. . Thereafter, the wafer fixing table 24 tilted to a predetermined angle by the angle adjustment screws 29a, 29b, and 29c is fixed to the adjustment holding cylinder 26 by the locking screws 30a, 30b, and 30c, and the adjustment holding cylinder 26 is A fixing screw 32 is screwed into a support screw 31 that slides into the reference outer cylinder 1 and passes through the screw hole 23 to support the crystal wafer 34 with the polishing margin adjusted. If the angle polishing jigs combined in this way are arranged on the lapping board 33 as shown in the figure to perform normal lapping polishing, it is possible to use a large number of types of fixing tables with different angles of inclination of the wafer fixing surface, as in the past. The main surface of the crystal wafer 34 can be easily adjusted to have an arbitrary inclination in the X-axis direction and the Y-axis direction from the reference plane of the crystal wafer attached to the fixing table 24 without preparing a Easily create the desired crystal plane.
Moreover, it becomes possible to perform lap polishing accurately.

(f) Effect of the invention As is clear from the above explanation, the angle polishing jig according to the present invention allows the crystal wafer to be polished at a desired angle of inclination while attached to the adjustment holding cylinder constituting the angle polishing jig. Since it can be adjusted accurately and easily, it is possible to easily lap polish the main surface of the crystal wafer to the desired crystal plane with high accuracy, and it has the advantage of improving the efficiency of the angle polishing work. It is extremely advantageous when applied to crystal correction polishing, angle polishing, etc. of various semiconductor wafers or various crystal substrates.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view for explaining a conventional angle polishing jig, and FIGS. 2 and 3 are longitudinal cross-sectional views of essential parts showing an embodiment of the angle polishing jig according to the present invention. FIG. 3 is a cross-sectional view taken along a cutting line. In the drawing, 21 is a reference outer cylinder, 22 is a reference end surface, 23 is a screw hole, 24 is a fixing base, 25 is a wafer fixing surface, 26 is an adjustment holding cylinder, 27 is a cylinder body, 28 is a through screw hole, 29a, 29b , 29c are angle adjustment screws, 30a, 30b, 30c are locking screws, 31
is a prop screw, 32 is a fixing screw, 33 is a lap board,
34 indicates a crystal wafer.

Claims (1)

[Scope of utility model registration request] A reference outer cylinder 21 having a flat reference end face, an adjustment holding cylinder 26 that slides in and out of the reference outer cylinder 21, and an adjustment holding cylinder 26 that is included in the adjustment holding cylinder 26 so that it can be tilted freely, and that holds the sphere in two parallel planes. A fixing table 24 having a surface for fixing the object to be polished is provided on one flat surface cut at
At least three angle adjustment screws 29a, 29b, 29c for adjusting in the dimensional direction, and a plurality of locking screws 3 for fixing the fixing base after adjusting the angle of the fixing base.
0a, 30b, and 30c are provided on the adjustment holding cylinder 26.