The role of aluminum in the crystallization of Cr–Si–Ni resistive films

Abstract

The microstructure and electrical properties of both annealed Cr–Si–Ni and Cr–Si–Ni–Al films with an atomic ratio [Si]/[Cr]>2 were investigated. When sputtered amorphous Cr–Si–Ni and Cr–Si–Ni–Al films were heated up to temperature of 600 °C, they all were found to crystallize through two distinct stages. The first stage was due to the primary crystallization of nanocrystalline CrSi 2 and Si phase for Cr–Si–Ni films (or Cr(Si,Al) 2 and Si phase for Cr–Si–Ni–Al films), while the second stage was due to crystallization of the residual solute-enriched amorphous phase into CrSi 2 (or Cr(Si,Al) 2) and Si phase. The addition of Al into amorphous Cr–Si–Ni films caused the coarsening of the primary crystallization phase, resulting in a significant increase of both the electrical resistivity and the temperature coefficient of resistance (TCR) for the annealed films. Meanwhile, the subsequent crystallization of the residual solute-enriched amorphous phase was affected, resulting from the combined redistribution of Cr, Si, Al and Ni elements between the primary and parent amorphous phases.