Growth Morphology of Boron Doped Single Crystal Diamond

TL;DR

This study investigates how boron doping affects the surface morphology, growth rate, and vibrational properties of single crystal diamond films grown via microwave plasma CVD, revealing the influence of nitrogen addition.

Contribution

It provides new insights into the effects of boron concentration and nitrogen doping on the morphology, growth rate, and Raman spectral features of homoepitaxial diamond films.

Findings

Surface morphology changes with boron concentration

Nitrogen improves surface morphology and growth rate

Raman spectra show shifts related to boron content

Abstract

Boron-doped single crystal diamond films were grown homoepitaxially on synthetic (100) Type Ib diamond substrates using microwave plasma assisted chemical vapor deposition. A modification in surface morphology of the film with increasing boron concentration in the plasma has been observed using atomic force microscopy. Use of nitrogen during boron doping has been found to improve the surface morphology and the growth rate of films but it lowers the electrical conductivity of the film. The Raman spectra indicated a zone center optical phonon mode along with a few additional bands at the lower wavenumber regions. 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. However, shrinkage and upshift of Raman line was observed in the film that was grown in presence of nitrogen along with diborane in process gas.