Reverse CoSi(2) thermal stability and digitized sheet resistance increase of sub-90 nm polysilicon lines

Abstract

An equation for quantifying the CoSi(2) thermal stability of polysilicon lines ranging from 50 nm to 2 mu m is proposed for the first time. In contrast to the intuitive thinking of narrower lines having a worse thermal stability, the equation predicts the weakest thermal stability occurring at the super nominal line in 90nm technology. An interesting phenomenon of digitized resistance increase is also reported for the first time.