| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device which permits the number of times of mask use to be reduced by one. SOLUTION: Using a first mask 2, a second conductivity-type buried well 3 is formed, and a second conductivity-type impurity ion for determining the threshold of the transistor of a memory cell is implanted in a memory cell part 1. Using a second mask 9, a first conductivity-type wells 10, 10 are formed respectively at the memory cell part 1 and a second conductivity-type MOS transistor part 8. Using the second mask 9, an n+ diffused layer 11 and n+ diffused layer 14 are formed for determining the threshold of the transistor. |
