A dome-shaped cavity type microwave plasma chemical vapor deposition reactor for diamond films deposition

•A new design of dome-shaped cavity type MPCVD reactor has been described.•The new reactor has met all of the prerequisites imposed for a successful MPCVD reactor.•The new reactor could be used safely at high input microwave power levels, say 10 kW.•The uniform and high quality diamond films have been experimentally deposited.

In this paper, a new type of microwave plasma chemical vapor deposition (MPCVD) reactor possessing a novel dome-shaped resonant cavity is described. Such a MPCVD reactor is required for efficient preparation of diamond films. It will be shown that by adopting a design outlined in this paper, a MPCVD reactor fulfilling all different requirements for reliable, long-time operation at high input microwave power levels could be optimized. Experimental results will be given showing that with the new MPCVD reactor, an input microwave power of up to 10 kW at 2.45 GHz could be applied, and at an input power of 8.5 kW, uniform and transparent polycrystalline diamond film of high quality and high purity could be deposited on 2 inch diameter silicon substrates, at a deposition rate of about 3.5 μm/h.