Mechanisms and Reaction Paths for Surface Roughening and Epitaxial Breakdown During Molecular Beam Epitaxy: Fundamental Limits

Fully-strained Ge1-xSnx layers were grown on Ge(001) to probe the role of incorporated Sn concentrations (C Sn = 1 x 1018 cm-3 to 6.1 at%) on surface roughening pathways leading to EB during LT-MBE (155°C) of compressively strained films. Sn mediates surface morphological evolution through two competing pathways. With x ≲ 0.02, the dominant effect is a Sn-induced smoothening of the surface. At higher x there is a change in Ge1-xSn x(001) growth kinetics due to a rapid increase in compressive strain. This leads to a reduction in h1 with increasing x as strain-induced roughening overcomes the smoothening effects and increases in the roughening rate. I show that by varying C Sn I can controllably manipulate the roughening pathway, and hence h1, over a very wide range.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science and Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Bratland, Kenneth Arnold, Jr

Contributors dc:contributor

• Greene, Joseph E.

• Physics, Condensed Matter

Language dc:language

eng

Identifier

(MiAaPQ)AAI3101802

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/82740