Suppression of boron segregation for shallow source and drain junctions in semiconductors

摘要

A method in the manufacture of ultra-large scale integrated circuit semiconductor devices suppresses boron loss due to segregation into the screen oxide during the boron activation rapid thermal anneal. A nitridation of the screen oxide is used to incorporate nitrogen into the screen oxide layer prior to boron implantation for ultra-shallow, source and drain extension junctions. A second nitridation of a second screen oxide is used prior to boron implantation for deeper, source and drain junctions. This method significantly suppresses boron diffusion and segregation away from the silicon substrate which reduces series resistance of the complete source and drain junctions.