Measurement of residual stress in diamond films obtained using chemical vapor deposition

Diamond films were deposited on a p-type Si substrate using the hot filament chemical vapor deposition (HFCVD) method. Residual stresses in the films were subsequently measured using the curvature, the X-ray diffraction (XRD) sin(2) psi, and the Raman peak shift methods. Results from the three methods were in agreement and indicated that residual stresses changed from compressive to tensile with increasing film thickness, bur the maximum or minimum extent of the stresses measured by the Raman and XRD methods was 3-5 times larger than those by the curvature method. These results were correlated with the results from the determination of Young`s modulus and total peak shifts by the XRD and the Raman methods. Young's moduli of diamond films were measured by the sonic resonance method, and the peak shift due to residual stress was separated from the total peak shift using the beam bending theory. After the adjustment, the disparity among the stress measurements was significantly reduced and a stress range of -0.5 GPa to +0.5 GPa was obtained.