| 摘要 |
PURPOSE:To reduce an unevenness in side-etching dimensions by selectively diffusing impurities through a mask formed on a polysilicon layer, selectively removing the polysilicon layer to form a high-density impurity region and further forming a low-density impurity region. CONSTITUTION:A mask film 14' is formed on a polysilicon layer 13 through patterning process, and impurities are selectively picked up on the polysilicon layer 13, using the said mask layer as a mask. Next, the polysilicon layer 13 where impurities are diffused is selectively etched so that the etched parts are removed. Following this procedure, a high-density impurity region 17 is formed, using the mask film 14 as a mask. Then the mask film 14 is removed and a low-density impurity region 19' is formed using the exposed polysilicon layer 13 as a mask. After this step, a phosphorus silicate glass layer 20 is formed and a metal wiring layer 22 is formed on electrode contact windows 21, 21'. |
