Mechanism on M (MNi, Mo, NiMo) as deep level impurity reducing the TCR of Si-rich CrSi resistive films

Abstract Cr Si–M (M Ni, Mo, Ni Mo) resistive films were prepared by magnetron sputtering technique at the same process conditions. Experimental results shows that the metal M can reduce the temperature coefficient of resistance (TCR) of Si-rich Cr Si resistive films, and that the resistive films follow the sequence of Cr Si Mo (6.34 at%)  Si Ni (9.97 at%)  Si Ni (6.08 at%) Mo (2.47 at%) according to TCR tending to zero. XRD analysis reveals that CrSi 2 is the main conductive phase in the prepared Cr Si–M resistive films. In order to explore the reasons that M can reduce the TCR of Si-rich Cr Si resistive films, first principles was used to study the influence of M on the performance of CrSi 2 from state density and band structure. The first-principles study on M-doped CrSi 2 shows that M may exist in CrSi 2 semiconductor in the form of deep level impurity, and an energy band model on both Ni and Mo-doped CrSi 2 is constructed to reflect the results of first-principles simulation. Based on the established model, a mechanism is proposed that deep level impurities as electron traps capturing electrons and the formation of tight-binding excitons can suppress the non-equilibrium hot carriers against being contributed to the conductivity of CrSi 2 semiconductor. As a result, the TCR of Si-rich Cr Si resistive films is reduced due to the doping of M as deep level impurity.