Method for forming an ultra-shallow junction in a semiconductor substrate using a nuclear stopping layer

摘要

A method for forming an ultra-shallow junction in a semiconductor substrate is provided. A semiconductor substrate having a top surface is prepared. A dielectric layer is then formed on the top surface. A first ion implantation process is carried out to implant a plurality of heavy ions into the dielectric layer at a first ion range Rp. Thereafter, a second ion implantation process is carried out to implant a plurality of less-heavy ions into the dielectric layer at a second ion range Rp. The second ion range Rp is smaller than said first ion range Rp. A portion of the plural less-heavy ions are decelerated by the previously implanted heavy ions and are implanted into the semiconductor substrate, thereby forming a ultra-shallow junction containing the less-heavy ions. Subsequently, the dielectric layer is completely removed.