| 摘要 |
PURPOSE:To reduce a drain junction leak current of a cell in which a mask ROM is programmed by impeding invasion of an impurity for programming into the drain of MOS transistor to form a cell. CONSTITUTION:A gate insulating film 2, a gate electrode 3 consisting of polysilicon and an n<+> type drain 5, etc., are formed on a semiconductor substrate. The gate electrode 3 is formed and overhanged toward the drain at the area in contact with the drain 5 and the drain 5 is drawn back from the channel side as much as the overhang of the gate electrode 3. Moreover, the resist 10 and gate electrode 3 are overlapped with each other and the overlapped portion has the length Y in the channel direction. Therefore, on the occasion of implanting impurity for programming, invasion of impurity for programming can be impedeted for the drain 5 and thereby increase of drain junction leak current due to deterioration of crystal condition at the side end portion of the channel can be prevented. |
