SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To provide a semiconductor device and a method for manufacturing it in which the influence of a wafer surface or a conductive layer surface is suppressed and, in addition, a conductive layer of large sheet resistance value is stably formed. SOLUTION: In this method for manufacturing an implantation resistance element (semiconductor device), a first dopant is ion-implanted near the surface of a semi-insulating GaAs semiconductor substrate 1, for formation of a doped layer, and then the doped layer is annealed and then the doped layer is activated so that conductivity is given to the doped layer to form a conductive layer 3, and second dopant is ion-implanted into the conductive layer 3 in shallow manner with energy lower than the ion implantation, and a thin high resistance layer 2 is so formed on the conductive layer 3 that at least a part of its surface is exposed to the outside. As a result, a semiconductor device which is hard to have an influence of the surface condition is manufactured, and the conductive layer 3 of high sheet resistance is stably formed.