Residual stress distribution in the direction of the film normal in thin diamond films

The residual stress distribution in the direction of the film normal in thi n diamond films deposited on Si substrate has been evaluated together with the distribution of Young's modulus. The films were deposited on the substr ate by the microwave chemical vapor deposition method. It has been observed that the curvature of the diamond films delaminated from the Si substrate is functionally dependent on the film thickness. Young's modulus, which has been estimated by the film bending test in conjunction with a finite eleme nt method of analysis, appears to be gradually decreasing towards the adhes ion interface. On the basis of detailed measurement of curvature and with t he aid of Raman spectroscopy, the residual strain distribution in the film has been evaluated. Although the average intrinsic stress was tensile as re ported earlier, we have found that a huge compression concentrates in the v ery small region near the adhesion interface. This finding shows evidence t hat something happens on the interface, which is absolutely different from the subsequent process of film growth. (C) 1999 American Institute of Physi cs. [S0021-8979(99)01113-5].