PURPOSE: To enable polishing without causing excessive polishing and damage by using a surface plate provided with a brush wherein an end of filling-tip surface is flat, and the diameter of a filling tip end is larger than the width of a semiconductor layer between thin films.
CONSTITUTION: A brush 12 having elasticity is fixed on the whole part of the abrasive surface side of a surface plate 11; this brush 12 has fillings whose tips-surface exhibits a flat plane 14; after a thin film 3 is selectively stuck on the surface of a single crystal substrate 2, a semiconductor layer 4 is formed on the substrate 2 surface. When the surface of the layer 4 is polished, mechanochemical polishing is applied by using alkaline solution as abrasive which does not react with the film 3 but react with the layer 4. When the polishing is finished, the thickness 6 of the film 3 becomes equal to the thickness 7 of the layer 4. In the case where the filling tip diameter of the brush 12 is larger than the width 5 of the layer 4, a flat surface 15 of the filling-tips does not get into the layer 4. Thereby an island region of the flat layer 4 free from damage and defect can be formed.
SATO HIROSHI
SHIMANOE MUNEHARU
