Investigation of thermal stability, phase formation, electrical, and microstructural properties of sputter-deposited titanium aluminide thin films

Titanium aluminide thin films are being considered as coating materials for high temperature applications due to their high melting points and high oxidation resistance. In this study, Ti₃₇Al₆₃ and Ti₅₃Al₄₇ thin films are deposited onto SiO₂ substrates by RF magnetron sputtering using compound targets and then annealed in vacuum to investigate the properties of the films. Rutherford backscattering spectrometry, X-ray diffractometry, transmission electron microscopy, and four-point probe measurements are used to analyze the characteristics of Ti₃₇Al₆₃ and Ti₅₃Al₄₇ thin films for high temperature electronics applications. The films show good thermal stability up to 700 °C for 1 h in vacuum. Reasonable resistivity is obtained when appropriate compositions and anneal conditions are used.