UHREM investigation of stacking fault interactions in the CVD diamond structure

An investigation of complex defect configurations arising from the interact ion between stacking faults in diamond thin films prepared by thermal-enhan ced chemical vapour deposition (CVD) on silicon substrates is reported. The defects have been determined by ultra-high resolution electron microscopy (UHREM) at 0.12 nm resolution. Extensive image simulation has been used to deduce their detailed core structures and to propose plausible 3D atomic-sc ale models. Two particularly interesting examples are shown: the first cons ists of intrinsic and extrinsic stacking faults intersecting to form two op posite stair-rod dislocations, while the second results from the interactio n between adjacent extrinsic stacking faults and a parallel twin interface. To our knowledge, this is the first time that such types of extended defec t configurations, which are quite representative of the dominant defect str uctures in CVD diamond, have been reported. (C) 1999 Elsevier Science S.A. All rights reserved.