1996 APS March Meeting Abstract

TITLE: Island morphologies in epitaxial growth

AUTHORS:

Uwe Hessinger, Michael A. Leskovar, Marjorie A. Olmstead, Lee Rumaner,
Fumio Ohuchi, Keiji Ueno and Atsushi Koma

ABSTRACT:

Growth of epitaxial films commonly occurs through the coalescence of
individual islands. The morphology of islands has therefore a key
importance for the film qualities desired. A uniform layer-by-layer growth
of the film is achieved when islands in the first layer coalesce to form a
uniform layer before a second layer nucleates; a non-uniform multi-layer
growth results from multiple layers successively nucleating on top of each
other before the first layer coalesces. We developed a kinetic model based
on an analytic solution of the diffusion equation between nucleation
events to calculate the evolving island morphology during growth. The
morphologies depend on flux of deposition, substrate temperature, and
activation energies for surface diffusion on substrate and deposited
material. By applying this theory to atomic force microscopy data of GaSe
multi-layer islands, we extract a value for the activation energy for Ga
diffusion across steps of GaSe.

Supported by NSF Grant No. ECS-9209652, DOE Grant No.
DE-FG06-94ER45516, and the Japanese New Energy Development
Organization.