Plasma arc-jet CVD

A common DC glow discharge PACVD system may be varied by operating the plasma at higher pressures and powers at which a DC arc discharge between the electrodes can be produced. In 1988, Kurihara et al.t l first reported the use of the DC plasma arc-jet CVD method, in which... 

Gas-phase activation above the deposition surface is essential for achieving appreciable diamond growth rates. The various CVD methods differ primarily in the way they produce gas-phase activation. The most abundant carbon-containing gaseous species present in most activated systems are methyl radicals and acetylene molecules which are also considered to be predominant growth precursors for diamond, almost independent of the deposition methods used. However, in systems that dissociate a significant fraction of H2, such as DC plasma arc-jet CVD, carbon atoms, aside from acetylene, are also abundant in the gas phase. 

One of the critical factors affecting growth rates is the gas-phase temperature which can be reached in a CVD method. A comparison of the various CVD methods to each other demonstratesl that typical linear growth rates correlate positively with estimated gas-phase temperatures (Fig. 1), approaching 1 mm h in atmospheric pressure plasma arc-jet CVD with temperatures around 6000 to 7000 K. The partial pressures of various gas species in typical CVD processes have been calculated as a function of... 

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