High-rate growth of single crystal diamond in microwave plasma in CH4/H2 and CH4/H2/Ar gas mixtures in presence of intensive soot formation

Morphology of Diamond Layers Grown on Different Facets of Single Crystal Diamond Substrates by a Microwave Plasma CVD in CH4-H2-N2 Gas Mixtures

“…The diamond coatings were synthesized in "hydrogen/methane/nitrogen" gas mixtures on SC diamond substrates using a microwave plasma CVD system ARDIS-100 (2.45 GHz, 5 kW) [13] with the following parameters: total gas flow rate of 500 sccm (H 2 :460/CH 4 :20/N 2 :20), pressure of 130 Torr, and microwave power of 2.8 kW. The substrate temperature during deposition was about 800 • C as measured through plasma by the Mikron M770 two-color pyrometer.…”

“…A decrease in the substrate temperature during the CVD process leads to an increase in α and a decrease in the crystallite size [15]. An increase in the methane [CH 4 ] concentration in the gas mixture leads to an increase in the growth rate and the α parameter, a decrease in the crystallite size, and an increase in the probability of secondary nucleation, i.e., the formation of new nuclei of diamond crystallites with different crystalline orientation on the diamond surface [13]. This hydrocarbon supersaturation facilitates the growth of the nanocrystalline film.…”

High‐order Stokes and anti‐Stokes Raman generation in monoisotopic CVD 12C‐diamond

“…The thermal conductivity of our 12 C‐diamond single crystal, which was measured by the steady‐state longitudinal heat‐flow method, was as high as k = 31.7 Wcm –1 K –1 . That is 44% higher than the value ( k = 22 Wcm –1 K –1 ) of the best CVD single crystal of nat C‐diamond .…”

Optical emission spectroscopy for diagnosis of diamond growth and etching processes in microwave plasma

“…The fiber tip was translated across the image of the plasma to record spatially resolved emission spectra along X or Z axes, parallel and perpendicularly to the substrate, respectively, with the istance of -25 to +25 mm along the X axis (counting from the plasma center), and from zero (the substrate position) to 50 mm along Z axis. The probed volume was a cylinder with diameter of 1.5-2 mm directed along the plasma ball diameter (Y direction), thus the spatial resolution of ~1.5 mm in the OES was obtained both for X and Z axes [2].…”

“…A relatively simple and non-perturbing method to measure the plasma parameters is the optical emission spectroscopy (OES) [1,2]. The OES advantage is also in a fast response to variation of the plasma parameters in the reactor.…”