| 摘要 |
PURPOSE:To reduce the whole process and manufacturing period and obtain a low cost semiconductor integrated circuit device by implanting impurity ion into a channel part of a predetermined MOSFET after forming a first layer metal (first metal layer) and a second insulating film. CONSTITUTION:A field oxide film 2 for element isolation, a gate oxide film 4, a gate electrode 5 and a source drain region 3 are formed and a first insulating film 6 are deposited on a P type silicon substrate 1 and a first metal layer 7 is formed on the upper surface thereof. Thereafter, a second insulating film 8 is deposited on the enture surface. Next, a through hole 9a is opened in the region A for implantation of impurity ion 10 to set ROM information of the channel part of predetermined MOSFET of mask ROM and simultaneously a second through hole 9b is opened in the region B to reduce the first layer metal 7 and the second layer metal 11 formed later. Thereafter, impurity ions 10 are implanted into the entire part without using any particular mask. |
