KR20050020271A - A Manufacturing Method And Device For Silicon Single Crystal Wafer - Google Patents

Abstract

PURPOSE: A method and apparatus of manufacturing a single crystal silicon wafer are provided to prevent the wafer from being easily broken by using sufficient discrepancy between a cleavage direction and a slicing direction. CONSTITUTION: A cleavage plane of a single crystal silicon ingot is detected. The single crystal silicon ingot is arranged to avoid the accordance between a first direction for slicing and a second direction vertical or horizontal to the cleavage plane. The single crystal silicon ingot is sliced. A flat or notch(13) of the ingot is arranged at a position with an angle range of 30 to 60 degrees from the cleavage plane.

Description

A manufacturing method and device for silicon single crystal wafer

The present invention relates to a method for manufacturing a silicon single crystal wafer, and more particularly, to a method and apparatus for manufacturing a silicon single crystal wafer for preventing the wafer from easily cracking in a slicing process or subsequent processing of a silicon single crystal wafer.

1A is a process flow diagram illustrating a slicing process of a typical silicon single crystal ingot, and FIG. 1B is a perspective view illustrating a slicing apparatus of a typical silicon single crystal ingot, and FIGS. 2A and 2B are each flat to a conventional silicon single crystal ingot. Or a perspective view illustrating a state in which a notch is formed.

As shown in Fig. 1A, when a silicon single crystal ingot 1 is produced from a silicon melt, it is subjected to a slicing process to make it into a wafer.

In general, various kinds of slicing devices are used for slicing, one of which is the wire SAW 2 shown in FIG. The wire saw 2 is a wire 5 wound around a roller 3 at regular intervals. The wire saw 2 is a wire 5 wound on a roller 3 buried in a slurry to reciprocate at high speed or in one direction. By moving, slicing of the ingot 1 is performed.

That is, the silicon single crystal ingot 1 is lowered and cut at a programmed speed while the wire is moved (round trip) at high speed, and the silicon single crystal ingot 1 is cut into a plurality of wafers (thin plates).

Slicing should be made in the direction perpendicular to the crystal center axis (b) and the wire (wire), not the ingot center axis (a), as shown in Figure 2a, so in order to determine the angle of the slicing center axis By measuring how far the center axis of the ingot crystal is off, we fine tune the position of the wire saw to be perpendicular to the crystal center.

In order to cut the ingot 1 using the wire saw 2, it is necessary to fix the beam 6 to the outer circumferential surface of the ingot 1 at a position opposite to the wire saw 2.

The relative angle of the flat 7 or the notch 8 to which the beam is attached is determined by the correction angles of the wire saw 2 and the ingot 1 as shown in FIG. 2B.

When the relative position between the wire saw 2 and the ingot 1 is determined, the ingot 1 is attached to the beam 6 through a portion of the flat 7 or the notch 8, and the beam 6 is operated. It is bonded to the work plate. When the adhesion of the beam 6 is completely cured, slicing is performed by finely correcting the angle of the wire saw 2 so that the angle of slicing is perpendicular to the crystal center axis of the ingot.

However, the method of slicing the silicon single crystal ingot of the above structure has had the following limitations.

The silicon single crystal wafer has a cleaved surface among the crystal forming surfaces, which means a fragile direction in the silicon single crystal wafer, and this is particularly important in a silicon wafer having a strong brittle characteristic.

When the cleaved surface is parallel to or similar to a wire mark or the like and in the vertical direction, the cleavage surface easily cracks or cracks during the slicing process and subsequent processes.

The flat or notch is formed in the direction of avoiding the cleaved surface, for example, in the 110 direction of the ingot. In general, since the lattice structure of the ingot is different depending on the ingot, the 110 direction may be the cleaved surface depending on the ingot. .

In this case, the direction of the slicing is close to the cleaved plane and to the horizontal and vertical. In this case, since the cleaved surface is close to the horizontal or vertical direction such as a wire mark, the wafer is easily broken or cracked in the slicing process and subsequent processes.

However, in the above-described process, since the slicing is performed according to the position of the flat or the notch without considering the cleavage surface, the direction of the slicing and the cleavage surface become horizontal or vertical, which causes a failure rate.

An object of the present invention is to change the direction of the flat or notched in the slicing process to sufficiently shift the cleavage direction and the slicing direction to prevent the breakage easily during the processing and distribution of the silicon single crystal wafer. And to implement a manufacturing apparatus.

Another object of the present invention is to implement a method and apparatus for manufacturing a silicon single crystal wafer, which can be sliced in an optimal state even when the silicon single crystal ingot is positioned so that the direction of slicing is shifted from the cleaving direction.

A method of manufacturing a silicon single crystal wafer for achieving the above object comprises the steps of: finding a cleaved surface of a silicon single crystal ingot; A positioning step of positioning a silicon single crystal ingot as much as possible avoiding a position where the angle of the slicing is perpendicular or horizontal to the cleaved surface; And slicing the silicon single crystal ingot.

The flat or notch of the silicon single crystal ingot is characterized in that it is formed at a position in the range of 30 to 60 degrees from the cleaved surface.

The flat / notch is characterized by being formed in four places to avoid cleavage surfaces.

The positioning step includes a measurement process of measuring a crystal center axis and an ingot center axis of the silicon single crystal ingot and their intersection points; Positioning the silicon single crystal ingot such that the slicing angle is perpendicular to the crystal center axis; Calculating an angle at which the silicon single crystal ingot can be rotated up and down in a plane including the crystal center axis and the ingot center axis such that the cleaved surface and the slicing surface are not in parallel or perpendicular to each other; And moving the ingot relative to the corrected angle by correcting a slicing angle of the silicon single crystal ingot according to the calculated angle.

The calculation of the slicing angle of the silicon single crystal ingot is determined by the length of the cone formed by the ingot center and the crystal center axis and the intersection thereof, and the distance between the crystal center and the ingot center, and the silicon single crystal ingot is determined by the wire saw. It is characterized in that the slicing surface and the cleaved surface as far as possible within the optimum operating range.

Slicing angle correction of the silicon single crystal ingot is characterized in that the position of the crystal center is determined in the vertical range of 0 to 15 minutes from the horizontal line passing through the ingot center.

The slicing direction of the silicon single crystal ingot lies in the range of 30 to 60 degrees with the cleaved surface.

The slicing angle correction of the silicon single crystal ingot is characterized by finely adjusting the direction of slicing by rotating the silicon single crystal ingot up and down based on the intersection point.

Correction of the slicing angle of the silicon single crystal ingot is characterized in that fine adjustment of the installation angle of the wire saw or external adjustment.

Correction of the slicing angle of the silicon single crystal ingot is characterized in that it is performed by changing both the vertical angle and the horizontal angle of the silicon single crystal ingot.

An apparatus for producing a silicon single crystal wafer according to an embodiment of the present invention is an apparatus for manufacturing a silicon single crystal wafer by slicing a silicon single crystal wafer, the measuring means for finding an ingot center axis, a crystal center axis, and an intersection thereof in the silicon single crystal ingot. and; Vertical adjustment means for adjusting the angle of slicing to be perpendicular to the crystal center by rotating the crystal center in a horizontal direction on the plane including the ingot center axis and the crystal center axis based on the found values; and the ingot center axis. Means for calculating a maximum angle capable of moving the crystal center axis in the up and down (vertical) direction about the intersection point on a plane including the crystal center axis; Fine correction means for correcting the angle of slicing by relatively rotating the silicon single crystal ingot vertically and horizontally based on the intersection point according to the angle calculated by the calculation means, and to the angle corrected by the fine correction means. Therefore, the silicon single crystal ingot is characterized in that it comprises a means for slicing at a predetermined angle.

The measuring means is characterized in that the X-ray diffraction analyzer.

The calculating means is a microcomputer which performs the calculation according to a calculation formula determined in consideration of the length of the cone formed by the ingot center axis and the crystal center, the distance between the ingot center and the crystal center, and the position of the cleavage surface. do.

According to the above-described configuration, the slicing process can be prevented from being horizontal or vertical to each other while the slicing direction and the cleaving direction of the ingot are slicing under optimum conditions. This can prevent the wafer from breaking easily.

Hereinafter, a configuration of a preferred embodiment of a method for manufacturing a silicon single crystal wafer according to the present invention having the above configuration will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view illustrating a flat formation state of the embodiment according to the present invention, Figure 4 is a perspective view illustrating the formation position of the ingot center axis and the crystal center axis, Figures 5a, 5b, 5c are each an angle of slicing A cross-sectional view illustrating the process of correcting.

The silicon single crystal ingot 10 in which the illustrated growing process is completed has its lattice structure and cleaved surfaces 11 and 11 ′ observed through an X-ray diffractometer.

In the present embodiment, since the wafer is easily broken during the slicing process when the flat 13 or the notch is placed around the cleaved surfaces 11 and 11`, the flat or notch in the preparation step for slicing is prevented. S should be positioned to avoid the cleavage direction.

In the present embodiment, the flat 13 and the notches are formed on four outer peripheral surfaces corresponding to the cleaved surface 11 as much as possible so that positioning of the ingot can be easily performed in the slicing process.

In this embodiment, the flat 13 and the notches are formed on the 110 surface in the lattice structure of the ingot.

The ingot 10 having the flat 13 or the notch is placed in the slicing process through a cleaning process or the like.

However, even when a flat 13 or a notch is formed on the 110 surface in this manner, the surface may be close to the cleaved surface horizontally or vertically depending on the ingot, so that the direction of the slicing is not close to the cleaved surface horizontally or vertically. It is necessary to fine tune the small angle.

In this embodiment, for this purpose, the step of finding the ingot central axis (A) and the crystal center axis (B) by imaging the silicon single crystal ingot 10 by X-ray before slicing, the found ingot center axis (A) ) And the angle between the crystal center axis (B) and the intersection point (P) of the two central axes are measured.

In this embodiment, the ingot center axis A, the crystal center axis B, the length L of the cone formed by the intersection point P, the ingot center axis A, and the crystal center axis B are The relative position of the ingot 10 and the direction of the slicing are finely adjusted by using the horizontal distance X formed.

That is, since the slicing is performed incompletely or depending on the relative position of the ingot relative to the wire saw, the slicing may be excessive, resulting in damage to the beam or the workbench. Therefore, the silicon single crystal ingot (10) may be prevented for optimal slicing conditions. Ingot center axis (A) and the crystal center axis (B) of) are located on the same plane.

In this case, however, the cleaved surfaces 11 and 11` may be positioned at or close to the vertical or horizontal position of the slicing direction, and may be easily broken during the slicing process and the subsequent processing. Fine tuning the direction is performed.

Since the direction of slicing avoids the cleaved surfaces 11 and 11 'in this fine adjustment process, it becomes possible to prevent the direction in which the saw mark or the like generated in the slicing process occurs from coinciding with the cleaved surface.

Looking at the process of finely adjusting the direction of the slicing, it is necessary for the process to put the ingot center axis (A) and the crystal center axis (B) on the same plane, ingots (centered on the intersection point P on the same horizontal plane) 10) to the left and right so that the direction of the slicing, that is, the angle between the wire and the crystal axis is perpendicular.

Next, the silicon single crystal ingot is rotated clockwise or counterclockwise about the ingot center axis A so that the direction of the slicing can avoid the cleaving direction as much as possible.

In this case, when the ingot is rotated a lot, the vertical direction of the silicon single crystal ingot 10 is increased, so that the wire saw 15 cannot perform the slicing process in an optimal state and the slicing is completed completely. It may not be excessive or may cause damage to the beam 17 or the work plate (Work Plate) attached to the ingot 10.

Therefore, the up and down rotation of the silicon single crystal ingot 10 is preferably limited to within a predetermined angle, which is the length (L) of the cone formed between the ingot center axis (A) and the crystal center axis (B), or the ingot center ( The distance X between A) and the crystal center B is determined.

In this embodiment, the ingot 10 is rotated up and down in a range of 0 to 15 minutes, preferably in a range of 0 to 15 minutes from the horizontal line passing through the ingot center (O), and the ingot 10 is rotated to change the direction of cleavage and slicing. The slicing process is performed to the maximum deviation.

In some embodiments, the vertical rotation angle may be performed in a range of 15 to 20 minutes from the horizontal line.

That is, the flat or notch is moved relatively so that the ingot is located at the relative position found by the above-described process, and is attached to the beam 17 on the outer circumferential surface of the silicon single crystal ingot at the position corresponding to the wire saw 15. The beam 17 is then attached to the work table 19.

Next, a silicon single crystal wafer manufacturing apparatus for performing the slicing process as described above will be described.

The apparatus for manufacturing a silicon single crystal wafer according to the present embodiment includes means for finding the crystal center axis A in the silicon single crystal ingot 10, a means for calculating a slicing angle, and a movement of the silicon single crystal ingot 10 in the horizontal and vertical directions. And means for slicing the silicon single crystal ingot 10 according to the angle.

In this embodiment, the means for finding the crystal center axis (B) is an X-ray diffraction analyzer, whereby it becomes possible to find the ingot center axis (A) and the crystal center axis (B), and the angles out of the two central axes are The delta, the ingot central axis A, and the crystal center axis B meet to measure the length L of the cone formed.

In the present embodiment, the angle at which the crystal center δ can be deviated as far as possible from the horizontal line passing through the ingot center O according to the calculation formula stored in the microcomputer is determined from the numerical values found by the X-ray diffraction analyzer described above. Calculate.

In the present embodiment, a means for rotating the position of the silicon single crystal ingot 10 in the horizontal and vertical directions about the intersection point P is provided according to the calculation result. According to the embodiment, it is also possible to adjust only the fine angle of the slicing by moving only one of the wire saw 15 or the ingot 10.

The following describes a method of manufacturing a silicon single crystal wafer of an embodiment according to the present invention having the configuration as described above, and the operation of the manufacturing apparatus thereof.

Using an X-ray diffraction analysis device, find the cleavage direction of the silicon single crystal ingot 10 after the drawing process is completed and flat or notch at four places (ideally in the non- cleavage direction (20, 20`)). To form.

The ingot center axis (A), the crystal center axis (B), and the intersection point (P) are found using the X-ray diffraction analyzer as described above for the flat 13 or the notched silicon single crystal ingot 10. .

Position the ingot center axis (A) and the crystal center axis (B) on the same plane, and rotate the ingot horizontally based on the intersection point (P) to be perpendicular to the direction of the crystal center axis (B) and slicing, that is, the wire. Adjust

In addition, the micro gum computer determines the center of gravity at the horizontal line passing through the ingot center O by determining the length L, the horizontal distance X, and the angle δ of the cone formed by the two central axes and their intersections. The maximum angle at which) can deviate in the vertical direction is calculated according to the input formula.

Then, within the range of the maximum angle, the ingot moving means rotates the silicon single crystal ingot in the horizontal direction and the vertical direction so that the direction of the slicing is close to 45 ° of the cleavage direction (11, 11 ').

When the relative position of the flat 13 or the notch of the ingot 10 is determined, the beam 17 is attached in order to be able to cut | disconnect at the wire saw 15 in this state.

Alternatively, according to the embodiment, after placing the ingot center A and the crystal center B on the horizontal line, it is also possible to adjust the slicing angle by moving the wire saw 15, and by moving the ingot relatively from the outside. It is also possible to adjust the fine angle of the wire.

The beam 17 is fixed to the workbench and slicing is performed.

By the method described above, the direction of the slicing is sufficiently out of the position perpendicular or horizontal to the cleavage direction, thereby preventing the wafer from being broken during the slicing process or the subsequent processing of the silicon single crystal wafer.

The scope of the present invention is not limited to the above embodiments, but is determined by the matters described in the claims, and it is obvious that the present invention includes various modifications and adaptations made by those skilled in the art in the same range as the matters described in the claims.

The present invention allows the cleavage direction and the slicing direction of the silicon single crystal ingot to be sufficiently mismatched to prevent the wafer from being easily broken.

In addition, the present invention is to calculate the maximum rotation angle of the silicon single crystal ingot as described above and to finely correct the position of the silicon single crystal ingot in this range, thereby slicing the silicon single crystal ingot manufactured in such an optimal state It is characterized in that to enable this.

Therefore, according to the present invention, not only in the process of slicing using a wire saw, but also in the subsequent processing of the entire wafer such as cleaning, peeling, grinding, inspection, polishing, lapping, and heat treatment, wafer transfer, and the like. In this case, it is possible to prevent cracking or the like.

In addition, small chips or cracks, which are difficult to visually distinguish, are present in the wafer and are prevented from being broken around the cracks or cracks in a later process.

Furthermore, by absorbing the unstable factors of the slicing process, such as lower cutting force of the slurry, damage to the main roller, poor wire tension, which may occur in the slicing process contributes to the stabilization of the slicing process.

1A is a process flow diagram illustrating a slicing process of a typical silicon single crystal ingot.

1B is a perspective view illustrating a slicing apparatus of a typical silicon single crystal ingot.

2A is a cross-sectional view illustrating a slicing angle of a conventional silicon single crystal ingot.

2B is a perspective view illustrating a state in which a flat or notch is formed in a conventional silicon single crystal ingot.

3 is a cross-sectional view illustrating a flat state of an embodiment according to the present invention.

4 is a perspective view illustrating positions of formation of an ingot center axis and a crystal center axis;

5A, 5B, and 5C are cross-sectional views illustrating a process of correcting angles of slicing, respectively.

* Description of the symbols for the main parts of the drawings *

10 ........ Silicone single crystal ingot 11,11` ......

13 ............. Flat or Notch 15 .......... Wire saw

17 ........ beam a, A ........ ingot central axis

b, B ...... determination center 0 ........... decision center

β ...... Decision center P ........... intersection

Claims (14)

Finding a cleaved surface of the silicon single crystal ingot; A positioning step of positioning a silicon single crystal ingot as much as possible avoiding a position where the angle of the slicing is perpendicular or horizontal to the cleaved surface; And slicing the silicon single crystal ingot. The method of manufacturing a silicon single crystal wafer according to claim 1, wherein the flat or notch of the silicon single crystal ingot is formed at a position corresponding to 30 to 60 ° from the cleaved surface. The method for manufacturing a silicon single crystal wafer according to claim 2, wherein the flat or notched portions of the silicon single crystal ingot are formed at four positions avoiding cleaved surfaces. The method of claim 1, wherein the positioning step, A measurement process of measuring a crystal center axis, an ingot center axis, and an intersection thereof of the silicon single crystal ingot; Positioning the silicon single crystal ingot such that the slicing angle is perpendicular to the crystal center axis; Calculating an angle at which the silicon single crystal ingot can be rotated up and down in a plane including the crystal center axis and the ingot center axis such that the cleaved surface and the slicing surface are not in parallel or perpendicular to each other; And And moving the ingot relative to the corrected angle by correcting a slicing angle of the silicon single crystal ingot according to the calculated angle. The method according to claim 4, wherein the calculation of the slicing angle of the silicon single crystal ingot, Determined by the length of the cone formed by the ingot center axis and the crystal center axis and the intersection thereof, and the distance between the crystal center and the ingot center, And the silicon single crystal ingot deviates from the slicing surface and the cleaved surface as much as possible within the optimum operating range of the wire saw. The method of manufacturing a silicon single crystal wafer according to claim 4, wherein the slicing angle correction of the silicon single crystal ingot is such that the position of the crystal center is determined in an upper and lower range of 0 to 15 minutes from the horizontal line passing through the ingot center. The method of manufacturing a silicon single crystal wafer according to any one of claims 1 to 6, wherein the slicing direction of the silicon single crystal ingot lies in the range of 30 to 60 degrees with the cleaved surface. The method according to any one of claims 4 to 6, wherein the slicing angle correction of the silicon single crystal ingot, A method for manufacturing a silicon single crystal wafer, characterized in that to finely adjust the direction of the slicing by rotating the silicon single crystal ingot in the vertical direction based on the intersection. The correction of the slicing angle of the silicon single crystal ingot, according to any one of claims 4 to 6, And finely adjusting the installation angle of the wire saw. The correction of the slicing angle of the silicon single crystal ingot, according to any one of claims 4 to 6, The method of manufacturing a silicon single crystal wafer, characterized in that for moving by adjusting the silicon single crystal ingot from the outside. The correction of the slicing angle of the silicon single crystal ingot, according to any one of claims 4 to 6, And changing both the vertical angles of the silicon single crystal ingots and the fine angles of the horizontal positions. An apparatus for manufacturing a silicon single crystal wafer by slicing a silicon single crystal wafer, Measuring means for finding an ingot center axis, a crystal center axis, and an intersection thereof in the silicon single crystal ingot; Vertical adjustment means for adjusting the slicing angle to be perpendicular to the crystal center by rotating the crystal center in a horizontal direction on a plane including the ingot center axis and the crystal center axis based on the found numerical values; Means for calculating a maximum angle capable of moving the crystal center axis in a vertical direction about the intersection on a plane including the ingot center axis and the crystal center axis; Means for correcting an angle of slicing by relatively rotating the silicon single crystal ingot vertically and horizontally based on the intersection point according to the angle calculated by the calculating means; And means for slicing the silicon single crystal ingot at a predetermined angle according to the corrected angle. 12. The method of claim 11, wherein the measuring means is an X-ray diffraction analyzer. The method according to claim 11, wherein the calculation means performs the calculation according to the calculation formula determined in consideration of the length of the cone formed by the ingot center axis and the crystal center, the distance between the ingot center and the crystal center, and the position of the cleavage surface An apparatus for producing a silicon single crystal wafer, which is a microcomputer.