The effect of LPCVD silicon nitride deposition on the Si-SiO2 interface of oxidised silicon wafers

Abstract

Low-pressure chemical vapor deposition (LPCVD) of silicon nitride on thermally oxidized silicon wafers changes the fundamental properties of the Si- SiO2 interface as a result of nitridation of the interface. This change results in an increase in the recombination rate of minority carriers at the silicon surface. The ammonia to dichlorosilane flow ratio during nitride deposition is a key parameter which affects the extent of this change. In addition, the recombination properties of the Si- SiO2 interface following nitride deposition are also influenced by charge in the nitride layer and by a change in the degree of hydrogen passivation of interface defects.