Date of Award

Fall 2003

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering - (M.S.)

Department

Electrical and Computer Engineering

First Advisor

Marek Sosnowski

Second Advisor

Haim Grebel

Third Advisor

Zafar Iqbal

Abstract

Hexagonal-wurtzite silicon phase silicon is an unusual polymorph of silicon with potentially useful electro-optical properties. Previous studies using a simple deposition system demonstrated that laser ablation of the standard cubic-diamond silicon produces droplets containing hexagonal-wurtzite crystallites. In order to study the process parameters and to deposit larger hexagonal crystals, a new pulsed laser ablation system with variable parameters was assembled and tested. Deposition expenments were performed in high vacuum with different laser pulse power. Raman spectroscopy showed that the new system successfully produces hexagonal-wurtzite silicon. The droplet size distributions, measured with an optical microscope, were found to depend on the laser pulse power, target-substrate separation and the target rotation. The droplets of hexagonal crystallites varied in diameter from less than a micron to 49 micrometers. The deposited material was examined using scanning electron microscopy and optically characterized by white light transmission.

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