Effect of composition on thermal stability and electrical resistivity of Ta-Si-N films

Abstract The role of composition on the resistivity and thermal stability of sputtered Ta–Si–N films have been studied using X-ray diffraction, Rutherford backscattering spectrometry, and sheet resistance measurement. Films with higher silicon to tantalum ratio were found to be more thermally stable and have higher sheet resistance than films with lower Si to Ta ratio. While Ta 0.28 Si 0.07 N 0.65 starts to crystallize at about 900°C, Ta 0.24 Si 0.10 N 0.66 and Ta 0.24 Si 0.12 N 0.64 were thermal for heat treatment below 1100°C. In-situ sheet resistance measurement also showed that the sheet resistance for the alloys varies with composition and decreases with temperature. Our results indicate that Ta–Si–N films would find other applications in semiconductor devices, beside being used as a diffusion barrier.