Dopant Segregation on Cavities Induced by Helium Implantation: The Case of Boron and Phosphorus

摘要

High dose He implantation, followed by a thermal annealing, is a suitable technique for metal gettering. When most of the papers focus only on the metallic impurity, they omit the influence of the dopants. In this paper, we shed light on the strong interaction between the cavity layer induced by helium implantation and the dopants. In order to study this interaction, we have used uniformly doped p and n type wafers implanted with helium at high dose and anneal using usual furnace annealing. Our results demonstrate a large segregation of the dopants within the cavity layer. The effect of the He gettering step on the dopants is discussed in this work by comparing the results of phosphorus and boron doped layers. This is of high interest for device fabrication.