FORMATION OF EXCELLENT SHALLOW N+P JUNCTIONS BY AS+ IMPLANTATION INTO THIN COSI FILMS ON SI SUBSTRATE

Abstract

Excellent shallow n + p junctions with a leakage current density of about 0.6 nA/cm2 have been fabricated by As+ implantation into thin CoSi films on Si substrates and subsequent drive-in/silicidation. The resultant junction characteristics are strongly affected by the implant conditions. A deeper as-implanted dopant profile is more helpful to drive the dopant within the silicides into the junction regions. Because the silicidation facilitates damage annihilation, the implant conditions forming excellent junctions in this scheme own large process window and thus yield low thermal budgets. Rapid thermal annealing was not favorable to forming junctions in this scheme because of its short annealing times for the arsenic drive-in.