ANALYSIS OF INTRINSIC STRESS-DISTRIBUTION IN GRAINS OF HIGH DUALITY CVD DIAMOND FILM BY MICRO-RAMAN SPECTROSCOPY

Micron-scale mapping of intrinsic stress in a foe-standing chemical va por deposition diamond film was performed by analysis of splitting and shift of the Raman diamond line. Stress distribution within individua l grains was observed for high quality (line width of 2.8-3.0 cm(-1)) 600 mu m thick free-standing film grown by microwave plasma enhanced c hemical vapor deposition. It has been shown that all the variety of th e Raman diamond line shapes observed can be presented by a superpositi on of two symmetric components with narrow widths. In some cases the t wo components can be completely resolved in succession by polarization analysis. (110)-Oriented crystals reveal anisotropic stress fluctuati ons up to 9 GPa of both signs (compressive and tensile). For grain siz es of 100-200 mu m high stressed regions of 200-300 mu m(2) area locat ed in the vicinity of edges and grain boundaries have been detected. P ossible sources of the high stresses of bath signs related to defect a nd impurity distributions within the grain are discussed. (C) 1997 Els evier Science S.A.