Optimization of annealing for ClusterBoron® and ClusterCarbon PMOS SDE

Abstract

High dopant activation and low implant damage are crucial in realizing the formation of a low resistivity ultra shallow junction (USJ). Future annealing process requires diffusion less activation and has ultimately define the junction depth. Conventional boron implant at ultra-low energies perform poorly in throughput and in energy contamination. Molecular species (B18H22) can provide implants with no energy contamination and low beam divergence along with self-amorphization. Implantation of ClusterBoron in combination with ClusterCarbon can provide junction depths in the 15-20 nm regime and achieve a higher level of dopant activation with conventional spike anneal. We used various ClusterBoron and ClusterCarbon energies and doses along with various anneal techniques to arrive at an optimum resistivity and junction depth for PMOS SDE applications. We carried out various analytical measurements like SIMS, sheet-resistance to understand the self-amorphization, enhanced dopant activation and the damage level effect of the dopants after the anneals. The results are discussed in detail in the paper