| 摘要 |
PURPOSE:To realize the so-called Hi-c structure without adding a masking process having high accuracy by diffusing an impurity introduced into an insulating film into a substrate under a capacitor electrode. CONSTITUTION:Arsenic (As<+>) is implanted so as to stay in an oxide film 22. Processes up to that time are executed without using a mask. A polysilicon layer 23 is patterned with the object of forming a capacitor electrode. The oxide film 22 in a section II except a capacitor forming section I is also removed through etching. The section II represents a transfer gate forming section. Boron (B<+>) ions are implanted as a channel dose. A gate oxide film 24 for a switch transistor is grown through second thermal oxidation. Impurities are diffused by a self-alignment system through the heat treatment. Accordingly, an n<+> type 26 is formed in the surface of an silicon substrate 21 and a p<+> type 21' in the inside in impurity distribution in the capacitor forming section I , and a p<-> type to which the channel dose is executed is shaped in the surface of the silicon substrate 21 and a p<+> type in the inside in the transfer gate section II. |
