METHOD OF FORMING THRESHOLD VOLTAGE CONTROL REGION OF SEMICONDUCTOR DEVICE TO MAINTAIN CONSTANTLY THRESHOLD VOLTAGE FROM ENTIRE CHANNEL REGION OF TRANSISTOR

摘要

Purpose: a kind of method for the starting voltage control zone being used to form semiconductor device is arranged to maintenance same threshold voltage for control a starting voltage by executing first and second ion implantation process in the entire channel region of a transistor. Construction: in order to determine that a region of activation and a field region, a separation layer (18a) are formed in semi-conductive substrate (10) on it. The first ion implantation process for starting voltage control dopant will carry out merely turning on region of activation between separation layer. It is that starting voltage control dopant will carry out forming a starting voltage control zone that one edge region of isolated area, which is partly opened with the second ion implantation process,.