| 摘要 |
PURPOSE:To enable the formation of the objective impurity distribution by self- alignment by a method an impurity of the same conductivity type as that of a substrate is selectively introduced in such a manner that part of the impurity in the neighborhood of the channel of the source and drain regions is cancelled. CONSTITUTION:A gate insulation film 12 is formed on the P type semiconductor substrate 11, and a gate electrode 14 is formed with an oxidation resistant mask material 13 as a mask. The source and drain regions 15 and 16 are formed by introduction of an N type impurity in this state. Next, oxide films 17 are formed on the side walls of the electrode 14. Then, the surface of the substrate 11 is exposed by removal of the films 17 of the regions 15 and 16. In this state, the entire surface of the substrated is covered with an oxide film 18 containing an impurity of the reverse conductivity type to that of the substrate. When the film 18 is removed by the technique of reactive ion etching, films 18' containing the impurity of the reverse conductivity type to that of the substrate is left on the side walls of the electrode. The impurity in the film 18' is diffused into the substrate; thereby the impurity in the parts of the regions 15 and 16 in contact with the films 18' is cancelled, and accordingly regions 19 of a low impurity concentration are formed. |
