Method for doping impurity into semiconductor crystal

Abstract

Abstract PURPOSE:To permit doping of impurities with high accurate alignment by a method wherein two kinds of mask members are formed one above another and the lower mask member is made smaller than the upper mask member through etching. CONSTITUTION:A Ti layer 3 and a photoresist 4 are formed on a conductive- type region 2 formed on a semiconductor crystal 1, and the photoresist 4 is exposed and developed to form an upper mask member 6. Then, the Ti layer 3 is etched with the upper mask member 6 being as a mask, so as to attain a lower mask member 5. A this time, the lower mask member 5 is made to have the reduced size at a certain ratio through side etching. When doping desired impurities 7, 8 into the semiconductor crystals 1, 2, an impurity doped region 7 is first formed with the upper mask member 6 being as a mask. Then, after removing the mask member 6, an impurity doped region 8 is formed with the lower mask member 5 being as a mask. By so doing, it becomes possible to control the gap between the regions 7 and 2 with high accuracy.

Inventors

• 👤 Kenichi Kikuchi
• 👤 健一 菊地
• 👤 Hideki Hayashi
• 👤 秀樹 林
• 👤 Toshiki Ehata
• 👤 敏樹 江畑
• 👤 Michitomo Iiyama
• 👤 飯山　道朝

Bibliographic Details