A thin layer of single-crystal silicon is produced by forming first trenches in a silicon substrate having (111) orientation; forming narrower second trenches at the bases of the trenches; anisotropically etching lateral channels (4) from the second trenches, until adjacent etch fronts (16) substantially...http://www.google.de/patents/US7169669?utm_source=gb-gplus-sharePatent US7169669 - Method of making thin silicon sheets for solar cells
