Shallow p+ layer in GaAs formed by zinc ion implantation

A shallow p+ layer with a steep boundary was obtained by Zn ion implantation and a capless annealing in an arsenic ambient. A capped annealing with a plasma deposited Si3N4 film resulted in a carrier concentration profile broadened by the diffusion enhanced by the interfacial stress between the capping film and the semiconductor. The p+ layer had a peak carrier concentration of 8×1019 cm−3 and a thickness of less than 1000 Å. Arsenic pressure in the annealing ambient also suppressed the enhanced diffuison of Zn in the ion-implanted GaAs.