Recent advances in high-growth rate single-crystal CVD diamond

• Published in: Diamond and related materials Vol. 18; no. 5; pp. 698 - 703
• Main Authors: Liang, Qi, Yan, Chih-shiue, Meng, Yufei, Lai, Joseph, Krasnicki, Szczesny, Mao, Ho-kwang, Hemley, Russell J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2009; Elsevier
• Subjects: ANNEALING; CHEMICAL VAPOR DEPOSITION; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); CHEMISTRY; Cross-disciplinary physics: materials science; rheology; CVD; DEFECTS; DIAMONDS; DIFFRACTION; Exact sciences and technology; FRACTURE PROPERTIES; Fullerenes and related materials; diamonds, graphite; GRAPHITIZATION; High growth rate; Homoepitaxial; Ion and electron beam-assisted deposition; ion plating; MATERIALS SCIENCE; Methods of deposition of films and coatings; film growth and epitaxy; MONOCRYSTALS; national synchrotron light source; PHOTOLUMINESCENCE; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; PLASMA; Plasma applications; Plasma-based ion implantation and deposition; Single-crystal diamond; Specific materials; SPECTRA; SUBSTRATES; THICKNESS; CVD; High growth rate; Plasma; Single-crystal diamond; Homoepitaxial; Growth rate; Synthetic diamond; Photoluminescence; Annealing temperature; Thermal annealing; Electronic properties; Vacancies; Phase transformations; Mechanical properties; Infrared spectra; Extended defects; Operating conditions; High pressure; High pressure high temperature method; Monocrystals; Natural diamond; Low pressure; Growth mechanism; Microwave discharge; Plasma deposition; Graphitization
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2008.12.002

There have been important advances in microwave plasma chemical vapor deposition (MPCVD) of large single-crystal CVD diamond at high growth rates and applications of this diamond. The types of gas chemistry and growth conditions, including microwave power, pressure, and substrate surface temperatures, have been varied to optimize diamond quality and growth rates. The diamond has been characterized by a variety of spectroscopic and diffraction techniques. We have grown single-crystal CVD diamond over ten carats and above 1 cm in thickness at growth rates of 50–100 μm/h. Colorless and near colorless single crystals up to two carats have been produced by further optimizing the process. The nominal Vickers fracture toughness of this high-growth rate diamond can be tuned to exceed 20 MPa m 1/2 in comparison to 5–10 MPa m 1/2 for conventional natural and CVD diamond. Post-growth high-pressure/high-temperature (HPHT) and low-pressure/high-temperature (LPHT) annealing have been carried out to alter the optical, mechanical, and electronic properties. Most recently, single-crystal CVD diamond has been successfully annealed by LPHT methods without graphitization up to 2200 °C and < 300 Torr for periods of time ranging from a fraction of minute to a few hours. Significant changes observed in UV, visible, infrared, and photoluminescence spectra are attributed to changes in various vacancy centers and extended defects.