Optimized subamorphizing silicon implants to modify diffusion and activation of arsenic, boron, and phosphorus implants for shallow junction creation

Abstract

Subamorphizing silicon preimplants were combined with relatively high dose drain (1014atoms/cm2) arsenic, boron, and phosphorus implants. The studies included as-implanted distributions. Extensive secondary ion mass spectrometry and spreading resistance profiling (SRP) analyses were carried out. It was found that the SRP analyses could be used to optimize the silicon implant energy. The resulting dopant profiles showed that not only was channeling suppressed and dopant diffusion reduced but activation also could be controlled. Equivalent medium doped drain regions of 150 nm were created using conventional furnace anneals. It was concluded that subamorphizing silicon preimplants could be used to create very shallow junctions in the medium dose drain regions of silicon-based devices.