Ion assisted deposition of crystalline TiNi thin films by electron cyclotron resonance plasma enhanced sputtering

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 555K was found for j(ion)/j(Ti+Ni) = 3.9 and E-i = 150eV. Substrate temperatures higher than T-cr resulted in a textured crystal structure. Factors affecting the composition of the deposited thin films are also discussed.