Heat transfer model of an iCVD reactor

Contrary to conventional HWCVD, the power consumption in the iCVD process is dominated by heat conduction rather than radiation. This is due to the fact that while the typical wire temperature for HWCVD is about 1750–2200 °C, for iCVD the temperature is only 250–500 °C. Typical deposition pressures are in the transition regime between the collision free regime, where the conduction is pressure dependent, and the collision mediated regime, where the conduction is pressure independent. The power loss due to heat conductivities of molecular nitrogen, glycidyl methacrylate (GMA) and tert-butylperoxide (TBPO) gases have been determined experimentally for these pressure regimes. The necessary power input to the filaments can be explained to be due to mainly heat dissipation by radiation and by gas conduction. This means that the dissociation process requires only very little power, about 2% of the total power consumption in a typical iCVD process.