Patent ID: 9117845
Filing Date: 2015-08-25
Classification: H01L

Abstract:
1. A method, comprising: forming an epitaxial layer on a semiconductor substrate; forming a buried region of a first conductivity type in the epitaxial layer; forming a well region of a second conductivity type in a laterally diffused metal oxide semiconductor (LDMOS) device; forming a reduced surface field (RESURF) oxide of the LDMOS device; forming a well region of the first conductivity type in the LDMOS device without concurrently forming a region of the first conductivity type in a bipolar junction transistor (BJT) device; forming, after forming the well region of the second conductivity type and after the forming the RESURF oxide, a gate oxide of the LDMOS device in contact with the RESURF oxide; and implanting a dopant of the second conductivity type to concurrently form a drift region of the LDMOS device and a base implant region of the BJT device, the drift region having a boundary intersecting an interface between a top surface of the epitaxial layer and the gate oxide of the LDMOS device.