THE EFFECTIVE CHEMICAL-VAPOR-DEPOSITION RATE OF DIAMOND

The effective chemical vapour deposition (CVD) rate of diamond, define d as the total thickness of diamond or as the mass of diamond deposite d per unit time, may be increased by orders of magnitude by increasing the substrate area per unit volume. To obtain these high deposition r ates, novel substrate designs are proposed that exploit three-dimensio nal arrays of small diameter wires or fibres. The analysis suggests th at the increased diamond output should be achieved with no increase in the net gas flow or power consumption, which could lead to the more e conomic production of solid diamond shapes and of composites containin g continuous or short diamond fibres, or particulate diamond. Estimate s for the cost of CVD diamond made by the fibre array technique are co mpared with reported current and predicted costs for CVD diamond and e stimates for the cost of CVD SiC.