Thermal treatment effects on hard and soft films measured by nanoindentation test

Nanoindentation measurements using the Berkovich diamond tip with a load up to 700 and 210 mN were performed on 1-μm hydrogenated diamond-like carbon (DLCH) films and 6-μm polyimide (PI) films under different thermal treatment. The average nanohardness and elastic modulus from nanoindentation measurements are 25.13 and 192.18 GPa for as-deposited DLCH film and 22.93 and 174.22 GPa for as-annealed DLCH film, respectively. The I _D/I _G ratio of Raman spectra is 1.72 for as-deposited DLCH film and 2.04 for as-annealed DLCH film. The average nanohardness and elastic modulus from nanoindentation measurements are 0.37 and 5.58 GPa for 300 °C as-cured PI film and 0.42 and 5.19 GPa for 400 °C as-cured PI film, respectively. The relative cured rate is 92.1% for 300 °C as-cured PI film and 100% for 400 °C as-cured PI film. Both the nanohardness and elastic modulus derived from nanoindentation test results can correlate well with the trend of Raman spectra and FTIR spectra for hard DLCH film and soft PI film under different thermal treatment effects.