The MSU/Fraunhofer Center for Coatings and Diamond Technologies has a long-term effort in plasma-assisted chemical vapor deposition (CVD) synthesis of single-crystalline diamond (SCD) substrates. Such substrates are of enabling importance for emerging applications such as diamond-based electronic devices, active and passive optical diamond crystals, and X-ray optical diamond components. These applications require challenging substrate dimensions, crystallographic perfection and ppb-level impurity control. For example, building commercially viable single-crystalline diamond electronic devices will require the availability of 300 µm thick wafers with diameters of 50 mm, intrinsic impurity levels of less than 5 parts per billion, dislocation densities and other structural defects of less the 100 per cm2 and controlled p- or n-type doping levels from 1016 – 1021 cm-3. Single-crystalline substrates of that size do not yet exist. Available substrates have a typical surface area of less than 100 mm2 and vary in quality. On the other hand much progress has been made in synthesizing high quality SCD with microwave plasma-assisted CVD (Schreck et al., 2014). Demonstrated growth rates exceed 50 µm per hour, the simultaneous synthesis of many crystals (Asmussen et al., 2008) and the multiple reuses of high quality seed crystals for homoepitaxial synthesis (Muehle et al., 2014)) promise a more cost effective production of ever larger and SCD substrates. P- and n-type doping processes have been demonstrated (Grotjohn et al., 2014; Ramamurti et al., 2009). Continual CVD reactor development aims at further improving process performance and material quality (Lu et al., 2013).
The talk will briefly introduce the MSU/Fraunhofer Center and then focus on CVD synthesis of single-crystalline diamond, current diamond technology projects at MSU/Fraunhofer and the capabilities and needs with respect to making larger and higher quality substrates.
Bios:
Dr. Thomas Schuelke is the Executive Director of Fraunhofer USA’s Center for Coatings and Diamond Technologies located on Michigan State University campus. In 2003 his Fraunhofer group joined forces with MSU’s microwave plasma group and has since collaborated on numerous diamond related R&D projects. Dr. Schuelke holds an Adjunct Professor appointment with the ECE department. Dr. Schuelke received M.S. (1992) and Ph.D. (1996) degrees in physics from the Technical University Dresden, Germany. Prior to joining Fraunhofer USA Inc., Dr. Schuelke spent two years with Chartered Semiconductor Manufacturing in Singapore as an R&D engineer working on plasma etching processes. Today his team performs applied R&D projects for industry and government with a focus on diamond materials and thin film coatings.
Dr. Schuelke’s particular research interests are in the areas of physical and chemical vapor deposition processes and systems technologies, thin film materials and applications.
Dr. Timothy Grotjohn is professor of electrical and computer engineering at Michigan State University. He also serves as the Director of Research and Development at Fraunhofer USA’s.