TY - JOUR
T1 - Impact of methane concentration on surface morphology and boron incorporation of heavily boron-doped single crystal diamond layers
AU - Rouzbahani, Rozita
AU - Nicley, Shannon S.
AU - Vanpoucke, Danny E. P.
AU - Lloret, Fernando
AU - Pobedinskas, Paulius
AU - Araujo, Daniel
AU - Haenen, Ken
N1 - Funding Information:
The Research Foundation ? Flanders (FWO) is gratefully acknowledged for financial support in the form of projects G0C0215N and S004018N. Part of the research leading to these results has been performed within the GreenDiamond project funded by the EC Horizon 2020 Program under grant agreement No640947. The computational resources and services used in this work were provided by the Flemish Supercomputer Center (VSC), funded by the FWO and the Flemish Government ? department EWI. P.P. is a Postdoctoral Fellows of the FWO.
Funding Information:
The Research Foundation – Flanders (FWO) is gratefully acknowledged for financial support in the form of projects G0C0215N and S004018N . Part of the research leading to these results has been performed within the GreenDiamond project funded by the EC Horizon 2020 Program under grant agreement N o 640947 . The computational resources and services used in this work were provided by the Flemish Supercomputer Center (VSC), funded by the FWO and the Flemish Government – department EWI. P.P. is a Postdoctoral Fellows of the FWO.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/2
Y1 - 2021/2
N2 - The methane concentration dependence of the plasma gas phase on surface morphology and boron incorporation in single crystal, boron-doped diamond deposition is experimentally and computationally investigated. Starting at 1%, an increase of the methane concentration results in an observable increase of the B-doping level up to 1.7 x 10(21) cm(-3), while the hole Hall carrier mobility decreases to 0.7 +/- 0.2 cm(2) V-1 s(-1). For B-doped SCD films grown at 1%, 2%, and 3% [CH4]/[H-2], the electrical conductivity and mobility show no temperature-dependent behavior due to the metallic-like conduction mechanism occurring beyond the Mott transition. First principles calculations are used to investigate the origin of the increased boron incorporation. While the increased formation of growth centers directly related to the methane concentration does not significantly change the adsorption energy of boron at nearby sites, they dramatically increase the formation of missing H defects acting as preferential boron incorporation sites, indirectly increasing the boron incorporation. This not only indicates that the optimized methane concentration possesses a large potential for controlling the boron concentration levels in the diamond, but also enables optimization of the growth morphology. The calculations provide a route to understand impurity incorporation in diamond on a general level, of great importance for color center formation. (C) 2020 Elsevier Ltd. All rights reserved.
AB - The methane concentration dependence of the plasma gas phase on surface morphology and boron incorporation in single crystal, boron-doped diamond deposition is experimentally and computationally investigated. Starting at 1%, an increase of the methane concentration results in an observable increase of the B-doping level up to 1.7 x 10(21) cm(-3), while the hole Hall carrier mobility decreases to 0.7 +/- 0.2 cm(2) V-1 s(-1). For B-doped SCD films grown at 1%, 2%, and 3% [CH4]/[H-2], the electrical conductivity and mobility show no temperature-dependent behavior due to the metallic-like conduction mechanism occurring beyond the Mott transition. First principles calculations are used to investigate the origin of the increased boron incorporation. While the increased formation of growth centers directly related to the methane concentration does not significantly change the adsorption energy of boron at nearby sites, they dramatically increase the formation of missing H defects acting as preferential boron incorporation sites, indirectly increasing the boron incorporation. This not only indicates that the optimized methane concentration possesses a large potential for controlling the boron concentration levels in the diamond, but also enables optimization of the growth morphology. The calculations provide a route to understand impurity incorporation in diamond on a general level, of great importance for color center formation. (C) 2020 Elsevier Ltd. All rights reserved.
KW - Impurity incorporation
KW - Methane concentration dependence
KW - DFT calculation
KW - CVD growth
KW - Boron-doped single crystal diamond
KW - CHEMICAL-VAPOR-DEPOSITION
KW - ELECTRICAL CHARACTERIZATION
KW - ELECTRONIC-PROPERTIES
KW - RAMAN-SPECTRA
KW - GROWTH-RATE
KW - THIN-FILMS
KW - CONDUCTIVITY
KW - TEMPERATURE
KW - SUBSTRATE
KW - MECHANISM
U2 - 10.1016/j.carbon.2020.10.061
DO - 10.1016/j.carbon.2020.10.061
M3 - Article
SN - 0008-6223
VL - 172
SP - 463
EP - 473
JO - Carbon
JF - Carbon
ER -