All ETDs from UAB

Advisory Committee Chair

Yogesh K Vohra

Advisory Committee Members

Eugenia Kharlampieva

Shane A Catledge

Brian Pillay

Joe Harrison

Document Type

Dissertation

Date of Award

2013

Degree Name by School

Doctor of Philosophy (PhD) College of Arts and Sciences

Abstract

The boron-doped single crystal diamond films were grown homoepitaxially on synthetic (100) Type Ib diamond substrates using a microwave plasma assisted chemical vapor deposition. The optical transmittance of the films was observed to change with the increasing boron content in the film. The effect of boron and nitrogen on the surface morphology of the film has been studied using atomic force microscopy. Use of nitrogen in process gas during boron doping improves the surface topography as well as gives rise to an increase in growth rate of diamond film. However, presence of nitrogen in the process gas significantly lowers the electrical conductivity of the film. Raman spectra showed a few additional bands at the lower wavenumber regions along with the zone center optical phonon mode for doped diamond. The change in the peak profile of the zone center optical phonon mode and its downshift were observed with the increasing boron content in the film. The sharpening and increase in intensity of the Raman line has been also observed in boron doped diamond film when grown in the presence of nitrogen. Temperature dependent electrical measurement between 90 to 680 K indicates two different conduction mechanisms were responsible for the semiconducting behavior of the film. The observed growth rate for homoepitaxial boron-doped diamond films were in the range of 5-16 µm / hour. Various level of boron doping (10^18 to 10^20 cm-3) was achieved during this study. The lowest resistivity of one of the boron doped samples at room temperature was calculated to be 0.12 ohmcm. The potential of boron-doped single crystal diamond in electronic devices is discussed.

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