Evaluation of residual stresses in chemical-vapor-deposited diamond films

Abstract

In this article we report the determination of residual stresses in diamond films grown on Si (100) by using a plate bending theory and a bimetal theory combined with micro-Raman spectroscopy. Raman spectra show that with increase in the film thickness the characteristic diamond line shifts from higher wave numbers (>1332 cm−1) to lower (<1332 cm−1), indicating a change in the nature of residual stress with the film growth. A plate bending theory and a bimetal theory are used to determine the distribution of residual stress induced by thermal mismatch. The modeled results show that the thermal stress decreases linearly along the film growth direction and the stress at the film/substrate interface decreases once the film becomes thicker. The difference from the Raman results is attributed to intrinsic stress, originating from lattice mismatch between the diamond and Si at the growth temperature and from a variation in microstructure of the film with its growth evolution.