Ion Assisted Deposition of Crystalline TiNi Thin Films by Electron Cyclotron Resonance Plasma Enhanced Sputtering

Abstract

Electron-cyclotron-resonance plasma enhanced sputtering with magnetic-mirror plasma confinement is characterized by low working pressures and large ion flux densities. TiNi thin films were deposited by this technique onto preheated Si (111) substrates. The crystal structure and composition of the films were analyzed by X-ray diffraction and Rutherford backscattering spectrometry, respectively. The substrate temperature T _cr necessary for deposition of crystalline TiNi films was determined as a function of the ion-to-metal flux ratio j _ion/j _Ti+Ni and ion energy E _i. T _cr as low as 555 K was found for j _ion/j _Ti+Ni=3.9 and E _i=150 eV. Substrate temperatures higher than T _cr resulted in a textured crystal structure. Factors affecting the composition of the deposited thin films are also discussed.