公开(公告)号：CA1209280A

公开(公告)日：1986-08-05

申请号：CA485177

申请日：1985-06-25

Applicant: IBM

Inventor： KINNEY WAYNE I ,  KOBURGER CHARLES W III ,  LASKY JEROME B ,  NESBIT LARRY A ,  TROUTMAN RONALD R ,  WHITE FRANCIS R

IPC: H01L27/08 ,  H01L21/033 ,  H01L21/76 ,  H01L21/762 ,  H01L21/8238 ,  H01L27/092 ,  H01L29/06

Abstract: PROCESS OF MAKING DUAL WELL CMOS SEMICONDUCTOR STRUCTURE WITH ALIGNED FIELD-DOPINGS USING SINGLE MASKING STEP A process for making a CMOS dual-well semiconductor structure with field isolation doping, wherein only a single lithographic masking step is required for providing self-alignment both of the wells to each other and also of the field isolation doping regions to the wells. The lithographic masking step forms a well mask and defines an oxidation barrier which acts as: an implant mask (absorber) during the ion-implantation of a field dopant of one type; an oxidation barrier over one well during the oxidation of the opposite-type well to form over the one well a sacrificial oxide layer which forms the alignment marks for subsequent formation of the field-doping regions; and a dopant-transmitter during the ion-implanation of an opposite-type field dopant which is simultaneously absorbed by the sacrificial oxide. As a result, there are formed field-doped oxide layers self-aligned to the wells so that, with a subsequent masking step, oxide field isolations are defined over the doped oxide layers. A heat cycle is then used to drive the field dopants into the corresponding field-doping regions.