| AVS 62nd International Symposium & Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS+2D+SE-WeM |
| Session: | Plasma Diagnostics, Sensors and Control II |
| Presenter: | Michael Ashfold, University of Bristol, United Kingdom of Great Britain and Northern Ireland |
| Authors: | M.N.R. Ashfold, University of Bristol, United Kingdom of Great Britain and Northern Ireland M.W. Kelly, University of Bristol, UK, United Kingdom of Great Britain and Northern Ireland B.S. Truscott, University of Bristol, UK, United Kingdom of Great Britain and Northern Ireland Y.A. Mankelevich, Moscow State University, Russia, Russian Federation |
| Correspondent: | Click to Email |
Most diamond chemical vapour deposition (CVD) employs microwave (MW) activated C/H (typically CH4/H2) gas mixtures. Many previous studies have sought to explore (and optimise) radical formation in such activated gas mixture, and the ways in which these radicals add to, and are accommodated on and in, the growing diamond surface.
Our activities in this area employ an interrelated three-pronged approach, i.e.
i) electronic spectroscopy methods (cavity ring down absorption and optical emission spectroscopies) to determine the spatial distributions of selected species (e.g. H atoms, CH and C2 radicals) as functions of process variables like the process gas mixing ratio, flow rate and total pressure, and MW power,
ii) complementary 2-dimensional (2-D) modelling of the plasma chemistry and composition with the aim not just of rationalising the spatial resolved column density data obtained in (i), but also enabling prediction of the concentrations of other key gas phase species (e.g. CH3 radicals, which are generally regarded as the dominant growth species) that are not amenable to spectroscopic detection, as functions of process condition, and
iii) quantum mechanical (QM) and QM-molecular mechanics (MM) calculations of the energetics of the elementary steps involved in radical addition to, migration on, and eventual accommodation on, a growing diamond surface.
This invited presentation will summarise the current understanding of diamond CVD from traditional C/H gas mixtures and results of recent studies designed to explore and explain the significant growth rate enhancements that can be achieved by adding trace amounts of nitrogen to such gas mixtures.