| 摘要 |
PROBLEM TO BE SOLVED: To increase the ratio of a memory cell and also to improve the drive capacity of peripheral circuit in a semiconductor integrated circuit device having a SRAM(static random access memory). SOLUTION: In order to form a low concentration semiconductor region in the source-drain region of a memory cell transfer MISFET Qt1 and an n- channel MISFET in a peripheral circuit, a manufacturing method consists of two steps. A first step of ion implanting both low impurity concentration semiconductor regions with n-type impurities and a second step of ion implanting the low impurity concentration semiconductor region in the n-channel MISFET of a peripheral circuit, only with the n-type impurities. |
