Application of LAMMS to Lateral Diffusion in Semiconductor Devices

The evolution of integrated circuit technology towards devices of finer vertical and lateral dimensions has made their analytical evaluation more difficult. Smaller line dimensions provide higher performance and greater density n+ and p+ channel transistors. The technical problem of maintaining the integrity of n+ and p+ devices as the connecting path becomes shorter must be characterized by both electrical and analytical techniques. 

This study applies the technique of LAMMS (Laser Ablation Microprobe Mass Spectrometry) to the analysis of the lateral diffusion of the dopants As, P, and B through Ta and Co silicides. Electrical data indicates that as the silicide layer between oppositely doped gate structures is shortened a rapid lateral diffusion path for n and p dopants can form which may counter dope adjacent polysilicon regions. LAMMS was used to analyze the effects of anneal temperature and time on the lateral diffusion of dopants in Ta and Co silicides.