A silicon wafer is mirror-polished until obtaining surface roughness Ra of 0.70-1.00 nm, Rq of 0.80-1.10 nm, or Rt of 4.50-7.00 nm. The resulting wafer is heat-treated at a temperature not lower than 1,200.degree. C. for 30 minutes to 4 hours in a hydrogen gas atmosphere. According to another aspect,...http://www.google.com/patents/US5744401?utm_source=gb-gplus-sharePatent US5744401 - Silicon wafer manufacturing method eliminating final mirror-polishing step 
