The relations among the process, microstructure, and nanomechanical properties of cosputtered Ta-Si-N thin films have been investigated. The microstructure evolution and varied hardness and elastic modulus property of Ta-Si-N were influenced by nitrogen flow ratios [FN2% = FN2/(Far + FN2) × 100%] during cosputtering together with phase formation and the composition of films. The microstructure of Ta-Si-N formed at a low 2-10 FN2% was an amorphous-like phase with nanocrystalline grains embedded in an amorphous matrix, while polycrystalline Ta-Si-N was obtained at a high 20-30 FN2%. The cubic TaN phase or (Ta1-x, Six)N solid solution is much easier to form polycrystallites than noncubic Ta5Si3, Ta2Si, and Ta2N phases from grazing incidence x-ray diffractometry results. Amorphous-like Ta-Si-N films had much higher nanohardness, stiffness, elastic recovery percentage, and a closer boundary compared to polycrystalline films. A maximum nanohardness of 15.2 GPa was obtained at 3 FN2%. An increased hardness of polycrystalline films at 20-30 FN2% is attributed to the higher amount of the hard TaN phase.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering