Date of Award

11-1996

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Engineering Physics

First Advisor

Yung K. Yeo, PhD

Abstract

Luminescence and absorption measurements were used to demonstrate the efficacy of ion implantation for introducing various classes of dopants into GaN. A wide range of implantation and annealing studies were performed with several dopant species (Ar, Zn, C, O, Si, Be, Mg, Nd, Er). Room temperature ion implantation was performed on MOCVD- and MBE-grown GaN samples at energies between 100 and 1150 keV with doses ranging from 1 x 1013 to 1 x 1015/cm-2. Conventional furnace annealing in flowing NH3 or N2 gas resulted in good implantation damage recovery at an annealing temperature of 1000°C for 90 min. Annealing temperature was found to be the determining factor in implantation damage recovery. It was discovered that surface degradation occurred for annealing in an NH3 environment at temperatures above 1000°C. An optimal annealing temperature of 1000°C and an optimal annealing gas environment of NH3 were found for the optical activation of Zn, Mg, Er, and Nd. Several new luminescence features were observed for the various dopants. Zn-implanted GaN was found to have a strong luminescence peak in the blue at 2.86 eV. The energetic location and width of this luminescence peak was insensitive to temperature changes and excitation intensity changes. These properties suggested that an internal Zn center transition was responsible.

AFIT Designator

AFIT-DS-ENP-96-09

DTIC Accession Number

ADA325090

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