Effect of residual stress on nanoindented property of Si∕C∕Si multilayers

Wu, B-H, Chung, C-K, Shih, T-R, Peng, C-C and Mohanty, U.S. (2009) Effect of residual stress on nanoindented property of Si∕C∕Si multilayers. Journal of Micro/Nanolithography, MEMS and MOEMS, 8 (3). Article number 033030 .

Abstract

The effect of residual stress on the nanoindentation property of Si/C/Si multilayers has been investigated. Sandwiched Si/C/Si multilayers were deposited on Si(100) substrates by means of ultrahighvacuum ion-beam sputtering at room temperature (RT). Four structures with different Si top-layer thickness of 5, 10, 25, and 50 nm and the constant thickness of C/Si underlayer at 100/50 nm were investigated in this study. The residual stress of the Si/C/Si (5/100/50 nm/nm/nm thick) film was about -17.76 GPa under compression, and its hardness was 20.39 GPa at RT. The compressive residual stress was decreased to -5.54 GPa with the increased thickness of Si toplayer up to 50 nm, and its hardness was reduced to (16.22 GPa at RT. The effect of Si top-layer thickness (5-50 nm) on Si/C/Si residual stress on the nanoindentation property were also discussed. The results showed that the thicker was the Si toplayer, the lower was the residual stress and hardness, which was good for the suppression of the buckling or wrinkling in the C/Si-nanocomposite film.