Deposition of stress-free diamond films on Si by diamond/β-SiC nanocomposite intermediate layers

Stress-free diamond films have been synthesized by using microwave plasma enhanced chemical vapour deposition (MWCVD) technique. Nanocrystalline diamond/β-SiC gradient composite film system was used as an interlayer for the diamond top layers. As a result, Raman phonon line shifts (obtained from diamond top layers) corresponding to diamond are recorded very close to the stress-free value of 1332 cm− 1. This implies an extraordinarily low biaxial compressive stress state in the diamond films. The interlayer accommodates to a considerable extent, the stress that occurs due to the difference in the thermal expansion coefficient of the diamond film and the underlying substrate.