| 摘要 |
PURPOSE: To obtain a semiconductor ROM device, which can be readily identified by forming contact plugs in an exposure source region and an exposure drain region, forming a concave region on an insulating layer on a gate layer and implanting impurities through the concave region and a gate electrode. CONSTITUTION: A photomask 800 is formed on an insulating layer 300 for specifying an opening in the region of a source 120 and a drain 140. The exposing part of the insulating layer at the top surface of the region of the source and the drain is removed by etching. Impurities are implanted into the region of the exposure source 120 and the drain 140, and contact plugs are formed. The exposing part of the photomask is formed on the insulating layer on a gate electrode 160. Then, a shallow insulating region or a concave region in a polycrystalline silicon gate region is formed by the etching of the insulating layer. Furthermore, ion implantation is performed through the insulating region or the concave region and the gate electrode region, and the cell is coded or programmed. |
