Analysis of stressed-gate SiO{sub}2 films with electron injection by conducting atomic force microscopy-microscopic observation for degradation mechanism of gate SiO{sub}2 films

摘要

We have developed a new method to analyze degradation of gate SiO{sub}2 films in actual metal-oxide-semiconductor devices, by using conducting atomic force microscopy (C-AFM). In C-AFM images of stressed gate SiO{sub}2 films, leakage current spots with a nanometer scale were successfully observed. The observed current spots show characteristic behaviors related to transient stress-induced leakage current which is detected by the macroscopic electrical measurement using the MOS capacitors. The appearance of the current spots is discussed based on the mechanism by which holes are trapped and detrapped at the stress-induced defects in the SiO{sub}2 film.