Growth of diamond thin films by dc plasma chemical vapor deposition

Abstract

Diamond thin films have been formed by dc plasma chemical vapor deposition with a high growth rate (∼20 μm/h). The diamond has been grown from methane (CH4) and hydrogen (H2) mixed gases on Si and α-Al2O3 substrates at a pressure of 200 Torr without surface scratching by diamond or c-BN powder. The obtained films have good crystallinity in the sense of electron and x-ray diffraction. Vicker’s hardness of the film is the same as that of natural diamond (∼10 000 kg/mm2). The influence of the dc discharge in a low vacuum (∼200 Torr) on diamond synthesis will be discussed briefly.

Studies on nucleation process in diamond CVD: an overview of recent developments

“…In DC PACVD and HFCVD, positive substrate biasing is effective for increasing nucleation of diamond [123,124], while in MW PACVD both positive and negative biasing can enhance diamond nucleation [122]. By varying the duration of biasing pretreatment [40] and/or the applied voltage [122] and current [6], nucleation density can be controlled over three to six orders of magnitude ( Figure 8 [122]).…”

What [plasma used for growing] diamond can shine like flame?

“…CVD methods, in contrast, rely on the production of gas-phase carbon-containing radical species close to a solid surface, from which diamond can be deposited as a kinetically stable product. Combustion flames, DC glow discharges [13][14][15][16][17][18] and DC plasma-jets [19][20][21][22][23][24] have all attracted passing interest, but most reported diamond CVD involves either hot filament or microwave plasma activation methods. [25][26][27][28][29][30][31] In common among the CVD methods, the growth of diamond (rather than other, or mixed phases of carbon) typically requires that the substrate is held at a temperature (Tsub) in the range 1000-1400 K, and that the carbon-containing precursor (typically methane) is present at the level of a few percent in an excess of hydrogen.…”

Combining nanostructuration with boron doping to alter sub band gap acceptor states in diamond materials

“…Diamond has a wide band gap of 5.5 eV and is chemically inert and stable compared to other widely investigated photocatalysts such as Cu 2 O. Furthermore, various diamond morphologies can be synthesized in the lab using detonation, 12 high pressure high temperature (HPHT) [13][14][15] and chemical vapor deposition (CVD) [16][17][18][19] growth techniques which use benign starting materials thus making the production process highly sustainable. This makes diamond very attractive as a sustainable photocatalyst for highly energetic reactions.…”