Electrical Activation Studies of Silicon Implanted Alx Gal-x N and Coimplanted GaN

Author

Elizabeth A. Chitwood

Date of Award

3-13-2003

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Yung Kee Yeo, PhD

Abstract

A comprehensive study of the electrical activation of silicon implanted Al_xGa_1-xN was performed as a function ion dose, anneal temperature, and aluminum mole fraction, Also, GaN coimplanted with silicon and nitrogen was investigated. Room temperature Hall effect measurements were used to determine carrier concentration and mobility. All the samples had a 500 Å encapsulant of AlN, and were implanted at room temperature with 200 keV silicon ions at doses ranging from 1x10¹³ to 1x10¹⁵ /sq cm. The GaN was also implanted with nitrogen under the same conditions in doses of 9x10¹² to 9x10¹⁴ /sq cm, respectively. The samples were annealed at temperatures ranging from 1200 to 1350 °C for 30 to 120 seconds in a flowing nitrogen environment. The aluminum mole fractions considered were 0.2 and 0.3. The electrical activation efficiency for the Al_0.2Ga_0.8N annealed at 1350 °C and implanted with 1x10¹⁵ /sq cm was almost 90%. While the Al_0.3Ga_0.7N annealed at 1350 °C and implanted with 1x10¹⁵ /sq cm exhibited only about 42% activation. The activation efficiency for all the samples increased with anneal temperature, but decreased with aluminum mole fraction. The mobilities and the carrier concentrations demonstrate an increase with the anneal temperature. Although the Al_0.2Ga_0.8N exhibited almost perfect activation, the mobility was generally low, only 50 /sq cm/Vxs. The coimplanted GaN showed surprisingly poor results. The highest activation efficiency was only 37% for the sample annealed at 1300 °C and implanted with a dose of 1x10¹⁵ silicon ions /sq cm. The mobilities for these samples were high, on average 100 /sq cm/Vxs. The carrier concentration and activation efficiency were found to increase with implanted dose. The mobilities, however, decreased as the anneal temperature increased.

AFIT Designator

AFIT-GAP-ENP-03-01

DTIC Accession Number

ADA414327

Recommended Citation

Chitwood, Elizabeth A., "Electrical Activation Studies of Silicon Implanted Alx Gal-x N and Coimplanted GaN" (2003). Theses and Dissertations. 4162.
https://scholar.afit.edu/etd/4162