Backscattering measurements of P+ implanted GaAs crystals

Abstract

Implantation of phosphorus and aluminium ions into GaAs is important in the investigation of the transformation processes which can take place during ion implantation and in the fabrication of heterojunctions. In this paper profiles of phosphorus, implanted into GaAs at different energies, temperatures, doses and dose rates and depth distributions of damage are discussed. For room temperature implantations, the range of the defect peak exceeds projected range (theoretical) by 30% and can extend to depths of several times higher than projected range (theoretical) for implantation at high temperatures. The profiles of implanted phosphorus are characterized by a complicated distribution. Using the RBS technique the estimated depth of phosphorus profiles ranges up to hundreds of nanometers. A discussion of the recently observed effect of high ion beam current density on damage and the distribution of implanted atoms is presented.