ORIENTING Si CRYSTALS WITH PULSED-LASER-INDUCED CRACKS.

Abstract

Recently, H. S. Tan et al described a pulsed-laser technique for the easy determination of the orientation of Si wafers and ingots. The technique produced cracks on a small area on the surface of the Si with the cracks being left brace lll right brace traces, i. e. , they delineated the intersections of left brace lll right brace planes of the Si with its surface. The authors stated; 'In principle, the deviation of the azimuthal orientation from the left bracket 100 right bracket and left bracket lll right bracket directions may be determined by measuring the deviation of the crack intersecting angles from 90 degree and 60 degree respectively'. How this principle may or may not be put into practice is the subject of this study. Charts for reading off orientations from crack directions on a Si crystal surface near (lll) and (100) are produced.