Method for forming a groove on a surface of flat plate formed of a nitride semiconductor crystal

摘要

Provided is a novel method for forming a groove composed of two smooth inclined surfaces on a surface of a flat plate formed of a nitride semiconductor crystal having an A, C, M-axes. In the present invention, a disk-shaped dicing blade is moved along a direction of the A-axis to form first and second inclined surfaces on the surface of the flat plate. The following mathematical formulae (I)-(III) are satisfied: 45 degrees≦θb−a≦60 degrees (I) 45 degrees≦θb+a≦60 degrees (II), 0 degrees≦|a|≦7.5 degrees, where angle θb represents an angle formed between a surface of the edge and a radial direction of the dicing blade in a cross-sectional view which includes the M-axis and the C-axis. The angle a represents an angle formed between the principal surface and the M-axis.

主权项

1. A method for forming a groove on a surface of a flat plate formed of a nitride semiconductor crystal having an A-axis, a C-axis, and an M-axis, the method comprising:
(a) moving a disk-shaped dicing blade along a direction of the A-axis to form a first inclined surface and a second inclined surface on the surface of the flat plate, wherein the flat plate has a principal surface; the disk-shaped dicing blade has an edge along the circumference thereof; the edge is in contact with the flat plate; the following mathematical formulae (I), (II), and (III) are satisfied:
45 degrees≦θb−a≦60 degrees  (I)45 degrees≦θb+a≦60 degrees  (II)0 degrees≦|a|≦7.5 degrees  (III) where the angle θb represents an angle formed between a surface of the edge and a radial direction of the disk-shaped dicing blade in a cross-section which includes the M-axis and the C-axis; the angle a represents an angle formed between the principal surface and the M-axis; and each of the first inclined surface and the second inclined surface has an arithmetical mean deviation Ra of not less than 0.046 and not more than 0.131.