Morphology of chemical vapor deposition diamond particles grown at high temperature

Abstract

{113} facets and irregular shapes of chemical vapor deposition (CVD) diamond particles are observed at high deposition temperature of 1200 degrees C on Co base substrate. Microwave plasma CVD is used for the diamond deposition with 2 percent of methane in hydrogen under 1.2 x 10(4) Pa (90 Torr). {113} facets form between {100} and {111} facets of diamond particles grown on heterogeneous substrate. This verifies that the condition for the stable {113} facet exists in CVD diamond growth. New small angle boundaries evolve on a flat surface of a growing single crystal diamond particle. Solid segments surrounded by the boundaries look like new grains, whose lattice orientations are misoriented to each other. The misorientation between the solid segments is small initially, but increases as the growth proceeds. Such evolution appears only on the upper particle surface which is parallel to the substrate surface irrespective of the facet index. The formation mechanism of the solid segments is discussed in terms of the lattice misfit within the diamond particle. (C) 1999 Elsevier Science S.A. All rights reserved.