Summary: ATOMISTIC FEATURES OF THE
AMORPHOUS-CRYSTAL INTERFACE IN SILICON
Noam Bernstein, Michael J. Aziz, Efthimios Kaxiras
Division of Engineering and Applied Sciences, Harvard University, Cambridge,
Received ..... ; Accepted in nal form .....
We simulate the amorphous-crystal interface in silicon using a combination of
interatomic potential molecular-dynamicsandtight-binding conjugate-gradient relax-
ation. The samples we create have high quality crystalline and amorphous portions.
We develop some localized measures of order to characterize the interface, including
a missing neighbor vector and the bond angle deviation. We nd that the measures
of order interpolate smoothly from a bulk crystal value to a bulk amorphous value
across a 7A thick interface region. The interface structures exhibit a number of inter-
esting features. The crystal planes near the interface are nearly perfect, with a few
dimer defects similar to the Si100 2 1 reconstruction. Interfaces produced with
one constant temperature simulation method are rough, with several layers of atoms
forming h110i chains and 111 facets. A di erent simulation method produces more
planar interfaces with only a few h110i chains.