Source drain implant during ono formation for improved isolation of sonos devices

Abstract

One aspect of the present invention relates to a method of forming a SONOS type non-volatile semiconductor memory device, involving forming a first layer of a charge trapping dielectric on a semiconductor substrate; forming a second layer of the charge trapping dielectric over the first layer of the charge trapping dielectric on the semiconductor substrate; optionally at least partially forming a third layer of the charge trapping dielectric over the second layer of the charge trapping dielectric on the semiconductor substrate; optionally removing the third layer of the charge trapping dielectric; forming a source/drain mask over the charge trapping dielectric; implanting a source/drain implant through the charge trapping dielectric into the semiconductor substrate; optionally removing the third layer of the charge trapping dielectric; and one of forming the third layer of the charge trapping dielectric over the second layer of the charge trapping dielectric on the semiconductor substrate, reforming the third layer of the charge trapping dielectric over the second layer of the charge trapping dielectric on the semiconductor substrate, or forming additional material over the third layer of the charge trapping dielectric.