Diamond Deposition on Graphite in Hydrogen Microwave Plasma

Abstract

Hydrogen plasma etching of graphite generates radicals that can be used for diamond synthesis by chemical vapor deposition (CVD). We studied the etching of polycrystalline graphite by a hydrogen microwave plasma, growth of diamond particles of the non-seeded graphite substrates, and characterized the diamond morphology, grain size distribution, growth rate, and phase purity. The graphite substrates served simultaneously as a carbon source, this being the specific feature of the process. A disorder of the graphite surface structure reduces as the result of the etching as revealed with Raman spectroscopy. The diamond growth rate of 3-5 µm/h was achieved, the quality of the produced diamond grains improving with growth time due to inherently nonstationary graphite etching process.

Synthesis of Diamond on SiC by Microwave Plasma Chemical Vapor Deposition: Comparison of Silicon-Face and Carbon-Face

“…Many researchers have studied H2 and H2-CH4 mixed plasma in different types of reactors such as hot filament chemical vapor deposition (HFCVD), Flame CVD, Microwave plasma chemical vapor deposition (MPCVD), and reactor of other types [5][6][7][8]. Each deposition technique has some advantages and disadvantages, but, the diamond of good quality can be deposited mainly using an MPCVD reactor because it has no filament, cathode, or anode inside the chamber, which thereby reduces the chances of contamination of the growing film [9][10][11]. Silicon carbide (SiC) is a kind of wide bandgap material, which can be used in applications where silicon (Si) components reached the performance limits.…”