| 摘要 |
PURPOSE:To enable to shorten the steps of manufacturing a semiconductor and to enable to highly integrate the semiconductor by selectively implanting, after forming a gate electrode, an impurity to an FET depleted by implanting the impurity after forming a gate oxidized film, thereby enhancing it. CONSTITUTION:A depleted MOSFET is etched at the window 15 of the part of a gate oxidized film 3 only at the necessary position after a resist 11 is removed, a polysilicon film 16 is then grown on the overall surface, and an impurity of phosphorus is then diffused, thereby lowering the resistance value of a polysilicon. Then, the gate electrode is patterned, a thin oxidized film 17 is grown, and arsenic (As<+>) ions are implanted through the film. The film 17 is then removed, a block oxidation 18 is then performed, boron ions are selectively implanted in a part of the adjacent layer 13 of an ROM to form a source and drain region 19, and a depletion type transistor is then enhanced, thereby forming a user ROM. Further, an insulating layer 20 such as PSG or the like and an electrode window 21 are formed. |
