Pre-Amorphization and Low-Temperature Implantation for Efficient Activation of Implanted As in Ge(100)

Abstract

To improve the activation of As implanted into Ge substrate, we have studied the influence of the crystallinty of implanted region with the ion implantation on As activation after post-annealing systematically. The impact of substrate temperature on As+ implantation to Ge (100) in the range from -100°C to 400 °C and the degree of amorphization with the ion implantation has been characterized. We have confirmed that the amorphization with As+ implantation is promoted efficiently at lower temperature due to the quenching of self-heating during the ion implantation. Such an enhanced amorphization of Ge by low temperature implantation is effective to suppress As cluster formation during the re-crystallization with post-annealing and results in the improvement of the As activation in Ge(100). We have also observed the enhancement of amorphization and As activation with pre-amorphous implantation.