Microstructural evolution and flaws in CVD diamond

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:230113

Barber, G D; Yarbrough, W A ^[1]; Gray, K ^[2]

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1. Intercollege Materials Research Lab., University Park, PA (United States)
2. Norton Diamond Film, Northboro, MA (United States)

Regrowth experiments on polished and optically transparent, thick free standing diamond were used to reveal the crystallographic relationships between various grains at the growth surface and show how the microstructure evolves locally. The results show that diamond growth occurs most rapidly on the defect free (110) surface and also suggest that flaw incorporation may occur or be aggravated by twinning during growth. This would imply that varying deposition conditions and methods are not likely, by themselves, to result in much improvement as textured growth with twinning during the growth process are features common to most diamond growth methods. Direct evidence is shown that the dominant growth axis by hot filament assisted CVD is along a <110> direction and that this is not dependent on the presence of defects. This implies that <110>, or near <111>, oriented grains tend to expand laterally (in the plane of the layer) with 2-fold rather than 4-fold symmetry.

• OSTI ID: 230113
• Report Number(s): CONF-950840--; CNN: Grant N00014-92-J-1125
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL DEFECTS
DIAMONDS
FILMS
GRAIN GROWTH
GRAIN ORIENTATION
MICROSTRUCTURE
SYMMETRY
TWINNING