Date of Award

3-1999

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Yung-Kee Yeo, PhD

Abstract

Electrical characterization has been performed on ion-implanted p-type 4H-SiC to assess the activation efficiency and implantation-related damage recrystallization with the intention of developing an implantation/annealing scheme. Low doped (Na - Nd = 5x10(exp 15)/cu cm) epitaxial p-type layers grown by MOCVD were implanted with Al or B at doses ranging from 1x10(exp 13) to 1x10(exp 14)/sq cm at room temperature or 500 deg. C. The electrical technique of Temperature Dependent Hall Effect (TDHE) indicated that Al and B act as shallow acceptors 4H-SiC with ionization energies of ^252 and ^285 meV, respectively. The highest activation efficiency for Al and B implanted samples was found to occur at anneal temperatures of ^1650 deg C and ^1550 deg C, respectively. The implantation dose resulting in the highest concentration for Al and B implantation was found to be 3x10(exp 13)/sq cm. An average peak mobility of ^200 sq cm/ V s was found for an Al implanted sample; this is considerably higher than the average peak mobility for the B implanted samples, ^100 sq cm/ V s. No significant gains in activation efficiency or mobility were evident with high temperature implantation compared to the room temperature implantation. Overall, Al implantation of 4H-SiC appears superior with regard to these properties compared to B implantation.

AFIT Designator

AFIT-GAP-ENP-99M-05

DTIC Accession Number

ADA361436

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