ESR STUDY OF MOSFET CHARACTERISTICS DEGRADATION MECHANISM BY WATER ININTERMETAL OXIDE

When intermetal oxide film which contains much water is deposited on M OSFET, degradation of hot carrier characteristics is enhanced. This me chanism is considered to be as follows. During the annealing process w ater is desorbed from the intermetal oxide. The desorbed water reaches the MOSFET and eventually hydrogens terminate silicon dangling bonds in the gate oxide. This paper describes a new approach which uses ESR to analyze this mechanism. The ESR measurement of number of the silico n dangling bonds in undoped polysilicon lying under the intermetal oxi de shows that water diffuses from intermetal oxide to MOSFET during th e annealing process. The water diffusion is blocked by introduction be tween the polysilicon and the intermetal oxides of P-SiN layer or CVD SiO2 damaged by implantation.