Date of Award

Spring 1980

Degree Type

Thesis - Restricted

Degree Name

Master of Science (MS)

Department

Physics

First Advisor

Pedrotti, Frank L.

Second Advisor

Burch, T. J.

Third Advisor

Deshotels, Warren

Abstract

The amphoteric behavior of Germanium ions implanted in Gallium Arsenide has recently been reported. The surface carrier concentration and activation efficiency have been found to depend critically on anneal temperature and ion dose. At low doses (<1 X 1014 ions/cm2 ) Ge-implants exhibit p-type activity at anneal temperatures 700°C through 950°C, and at high doses (>1 X 1015 ions/cm2 ) the implants are n-type in the same temperature range. The effect of a second implant, Gallium, on the electrical properties of Ge-implants of GaAs has been studied in this research in the dose range of 1 X 1013 to 3 X 1015 ions/cm2 and anneal temperature range of 700°C to 10000 C. The dual implants show significant improvement of p-type activation efficiencies over Ge single, implants and extension of p-type activity to higher doses and anneal temperatures than single implants. A maximum efficiency of 61% has been achieved at a dose of 1 X 1013 ions/cm2 and 950 C anneal temperature, compared to the maximum of 38% found in single implants at the same dose and anneal temperature. p-type activities were found to increase by a factor of 3 to 8 in dual implants in the dose range of 1 X 1013 to 3 X 1014 ions/cm2 and anneal temperature range of 700°C to i 950 C. The conversion to n-type occurs only at the two highest doses- 1 X 101 5 and 3 X 1015 ions/cm2 and only above 900 C anneal temperature. The results of this work have been reported in the paper entitled 'Dual Implants of Ga and Ge in GaAs'; the paper has been accepted for publication in the Journal of Applied Physics, 1980.

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