| 摘要 |
PURPOSE:To form a surface having decreased contamination with impurities and crystal defects, by subjecting the surface of a silicon substrate to the chemical treatments to form and remove an oxide film, the chemical treatments to form an oxide film and adsorb halogen thereto, and the heating in vacuum to remove the oxide film. CONSTITUTION:A degreased silicon substrate is (i) boiled in HNO3 to form an oxide film to the surface of the substrate, and treated with HF to remove the oxide film, and the process is repeated several times. The treated substrate is (ii) boiled in the solution consisting of 20% of NH4OH, 20% of H2O2 and 60% of H2O to form an oxide film on the surface, which is removed with HF. (iii) The substrate is boiled in the solution consisting of 60% of HCl, 20% of H2O2 and 20% of H2O to form a fresh oxide film on the substrate and at the same time, to adsorb halogen to the oxide film. Finally, (iv) the substrate is heated in high vacuum (>=1X10<-7> Torr) at about 650-900 deg.C to decomposed and evaporate the oxide film of the substrate and obtain a cleaned surface. |
