Resistivity and structural defects of reactively sputtered TiN and HfN films

Abstract

TiN and HfN thin films have been deposited by reactive r.f.-sputtering in an Ar-N 2 gas mixture under different condition of total gas pressure ( P T ) from 0.7 Pa to 5.3 Pa. Thin film X-ray diffraction studies show that the structure of the TiN films is gradually changed from TiN f.c.c. structure to amorphous with increasing P T . On the other hand, HfN f.c.c. structure with a strong (111)-preferred orientation is formed for all HfN films prepared with various P T . The resistivity of the films at room temperature ( ϱ rt ) increased with increasing P T in different ways between TiN and HfN. The films with ϱ rt ≤ 0.3 mΩm show √T dependence in conductivity at low temperature. HfN films with ϱ rt = 1.6 mΩm, the largest one measured, show an insulating behavior. The magnetoconductance Δσ(H) measurements showed that the spinorbit coupling of HfN is found to be stronger than that of TiN.