| 摘要 |
PURPOSE: To form a self-positioned source and a channel region prior to the formation of a gate by embedding the process stage of an electronic device in the manufacture of a non-electric power device. CONSTITUTION: In a P-type semiconductor substrate, positioning marks are formed by etching and a P-epitaxial silicon layer 152 is formed, and an n<+> -buried layer 154 is formed selectively in it and covered with an epitaxial P-silicon layer 156 which is sufficiently thick for heat treatment. Then an n-transistor 171 as a high-voltage power transistor is formed, deep n<+> -injection and high- temperature annealing are carried out. Further, an n<-> -tank for a low-voltage device is formed, high-voltage P tanks 170, 169, and 168 are formed in the epitaxial layer to form a low-voltage P tank, and all the tanks and well dopants are diffused through a high-temperature process, to form a field structure and a gate structure or a source and a drain regions positioned at the both. |
