Patent ID: 7037815

Claim:
A method for forming an ultra-shallow junction in a semiconductor substrate, comprising: providing a semiconductor substrate having a top surface; forming a dielectric layer on said top surface; doping a plurality of heavy ions into said dielectric layer at a first ion range Rp; doping a plurality of less-heavy ions into said dielectric layer at a second ion range Rp, wherein said second ion range Rp is smaller than said first ion range Rp, and wherein a portion of said plural less-heavy ions ae decelerated by said heavy ions and are implanted into said semiconductor substrate, thereby forming an ultra-shallow junction containing said less-heavy ions; wherein said doped heavy ions have a first peak concentration lying in said dielectric layer at said first ion range Rp, and said doped less-heavy ions have a second peak concentration lying in said dielectric layer at said second ion range Rp; and removing said dielectric layer.