| 摘要 |
PURPOSE:To prevent the semiconductor substrate surface of a source and drain forming region from damage by a method wherein the formation of side wall of a silicon oxide film on the side face of a gate electrode is unnecessitated. CONSTITUTION:After a gate oxide film 3 and a polysilicon film 4 are formed on the prescribed region surrounded by the thick field oxide film 2 on a silicon substrate 1, and a silicon oxide film 9 is formed on the polysilicon film 4 by performing a thermal oxidizing. A gate electrode pattern is formed on the silicon oxide film 9 using a photoresist 10, the silicon oxide film 9 on the part which is not coated with the photoresist 10 is removed by performing a reactive ion-etching using CF4 gas, etching gas is changed to CCl4, and the polysilicon film 4 located under the film 9 is removed by etching. Then, the source and drain region 8 having high density of impurities is formed by performing an ion-implantion. Subsequently, a polysilicon 4a is obtained by removing the prescribed amount of the polysilicon film 4 by performing a plasma etching using the silicon oxide film 9 as a mask, impurity ions 5 are implanted using said polysilicon film 4a as a mask, and a source and drain region 6 is formed.
|
