Depth-resolved correlation between physical and electrical properties of stressed SiNx gate insulator films

Abstract

The physical and electrical properties of SiNx gate insulator films with compressive and tensile internal stress have been investigated using various characterization techniques. The mechanical hardness measured by nano-indenter system showed the different distribution in the film depth direction according to the type of film stress. The uniformity of optical property inside films had a correspondence to the mechanical properties of stressed SiNx films, as well. The contents and bonding states of hydrogen influenced the mechanical and optical properties of stressed SiNx films. The leakage characteristics of tensile SiNx films with uniform physical properties exhibited the lower current density than the compressive films with ~10?7 A/cm2 until 8 MV/cm. The correlation between physical and electrical properties depending on the internal stress will suggest the appropriate optimization of SiNx gate insulator films to enhance the device performance and reliability.