| 摘要 |
PURPOSE:To make the positional setting of the following regions precise by a method wherein an insulation layer obtained by oxidizing the side surface of a polycrystalline Si layer constituting the gate electrode is made as a mask, when manufacturing an IGFET having the source and drain regions which are at a low impurity concentration under the gate electrode and at a high concentration in the region continuous thereto. CONSTITUTION:A gate oxide film 12 is adhered on a P type Si substrate 11, and an N type polycrystalline Si layer 13 of a fixed shape having an Si3N4 film 20 on the surface is provided thereon. An N type impurity ion is implanted through the film with said layer as a mask, thus first forming the N type source and drain regins 16 and 17 of low impurity concentrations coming into the lower surface of the layer 13 in the surface layer part of the substrate 1. Next, on heat treatment in a high temperature oxidizing atmosphere, the side surface of the layer 13 is changed into an SiO2 layer 130 extending outside by volume expansion. The layer is joined to the regions 16 and 17 by implanting the N type impurity ion again, resulting in the generation of the source and drain regions 14 and 15 of high impurity concentrations extending on both sides thereof. |
