| 摘要 |
PURPOSE:To make doping of impurities possible with accurate positioning of less than + or -1mum accuracy, by a method wherein the first doping is performed on the basis of the first pattern, and then the second doping is performed on the basis of the pattern which is made smaller than the first pattern by the fixed quantiy. CONSTITUTION:A Ti layer 3 is formed on the crystal surface by vapor deposition, and a resist pattern 4 is further formed thereon. The Ti layer is then processed by the method such as etching, and the resist 4 is removed to form a Ti mask 3'. After that, the first desired doping of impurities is performed to form an n<+> region 7 within the semiconductor crystal by implanting ion utilizing Se etc. Then the Ti mask 3' is etched isotropically to make smaller by the fixed quantity e.g. 0.3mum. For the above etching, the plasma etching with high accuracy is suitable. The desired second doping is performed utilizing the Ti mask 3'' as a mask. |
