| 摘要 |
PURPOSE:To prevent the reduction of film thickness of a gate electrode and obtain a field effect transistor with a good manufacturing yield by performing a source diffusion with this insulating gate as a mask, by foring a struture wherein an Si nitride film is superposed on a gate electrode on a gate insulting film. CONSTITUTION:The lamination of a gate oxide film 4, an As doped low resistance gate poly Si 5 and a nitride film 6 respectively in a fixed thickness is applied to a patterning by a photo resist film 7 resulting in the formation of an aperture part 8. Next, the nitride film 6, poly Si 5 and the gate oxide film 4 are successively etched by a reactive ion etching with this resist aperture part as a mask. Subsequently, boron is implanted as a base impurity, and a thin nitride film 10 is formed on the surface of the aperture part of the substrate 1, after the resist film 7 is removed. Next, a source region 3 is formed by implanting P as a source impurity with the insulating gate as a mask. Thereat, the P is implanted onto the surface of the base region 2 through the thin Si nitride film 10 but trapped into the thick nitride film in places other than it. |
