Plasma Chemistry Study in Plasma Doping

Northeastern University, Boston MA

Investigators

Abstract

0001378 Chan The objective of this proposed work is to explore plasma chemistry in Plasma Doping (PD) process and the development of in-situ diagnostics. The goals are: (1) to understand the characteristics of dopant ions in current dopant plasmas; (2) to experiment with new type of dopant plasmas with emphasis on the safety aspect; (3) to develop an accurate in-situ dose measurement technique; and (4) to develop analytical and numerical models for better predictions and control on doping profiles. The research will provide more precise and broader knowledge of processes that have significant plasma chemistry effects. In particular, present study can help the PI's optimize dopant recipes, process conditions, and provide a basis for the design and the calibration of implantation dose measurement. The approaches to achieve the above objective include experimental study, analytical modeling and simulation. Plasma doping experiments with varied process parameters and gas recipes will be performed. The simulations will be performed using existing tools such as PDP2, Crystal-TRIM etc. Plasma chemistry will be investigated by both analyzing the plasma components in the chamber and the dopant profiles in the implanted wafers. Since plasma components may be altered by target bias voltage, the emphasis will be put on the analysis of the implanted wafers and the development of in-situ diagnostics. A dynamic sheath model of multispecies plasma will be used to provide a basic function for fitting the experimental SIMS data of doping profile. Simulation tool Crystal-TRIM, which can simulate channeling effect, will be used to find implantation straggling and ranges. The influence of ion energy distribution, multiple ion species, pre-amorphaization and dopant diffusion enhanced by thermal effect and co-implanted non-dopant ions such as hydrogen and nitrogen, will be considered. ***