A STUDY ON THE RESIDUAL-STRESS MEASUREMENT METHODS ON CHEMICAL-VAPOR-DEPOSITION DIAMOND FILMS

Diamond films were deposited on the p-type Si substrate with the hot f ilament chemical vapor deposition (HFCVD). Residual stresses in the fi lms were measured in air by the laser curvature, the x-ray diffraction (XRD) d(phi psi) - sin(2) psi, and the Raman peak shift methods. All of the measuring methods showed similar behaviors of residual stress t hat changed from a compressive to a tensile stress with increasing the film thickness. However, values of residual stresses obtained through the Raman and XRD methods were 3-4 times higher than those of the cur vature method. These discrepancies involved the setting of materials c onstants of CVD diamond film, and determination of a peak shifting on the XRD and Raman method. In order to elucidate the disparity, we meas ured a Young's moduli of diamond films by using the sonic resonance me thod. In doing so, the Raman and XRD peak shift were calibrated by ben ding diamond/Si beams with diamond films by a known amount, with stres s levels known a priori from the beam theory, and by monitoring the pe ak shifts simultaneously. Results of each measuring method showed well coincidental behaviors of residual stresses which have the stress ran ge from -0.5 GPa to +0.7 GPa, and an intrinsic stress was caused about +0.7 GPa with tensile stress.