Recessed Oxide Isolation Process
Original Publication Date: 1986-Jan-01
Included in the Prior Art Database: 2005-Mar-08
A recessed oxide isolation process for forming high density bipolar structures is provided which minimizes crystal defects caused by silicon to oxide expansion mismatch during high temperature processing steps after recessed oxide is introduced into a semiconductor substrate. In this process, the recessed oxide is formed after the high temperature diffusion steps have been completed and the recessed oxide is grown at relatively low temperatures. The process provides for butted emitters and contacts, if desired. The process may be better understood by referring to Figs. 1 and 2 wherein the formation of an NPN bipolar transistor is illustrated. A P type semiconductor substrate 10 has an N type epitaxial layer 12 grown thereon with an N+ subcollector region 14 and P+ isolation regions 16 formed in any known manner.