Epitaxial synthesis of diamond layers on a monocrystalline diamond substrate in a torch microwave plasmatron

The epitaxial growth of a diamond single-crystal film in a torch microwave discharge excited by a magnetron of a domestic microwave oven with the power of ≤1 kW in an argon-hydrogen-methane mixture with a high concentration of methane (up to 25% with respect to hydrogen) at atmospheric pressure on a sub-strate of a synthetic diamond single crystal (HPHP) with the orientation (100) and 4 × 4 mm in size is obtained. A discharge with the torch diameter of ∼2 mm and the concentration of the microwave power absorbed in the torch volume of >103 W/cm3 is shown to be effective for epitaxial enlargement of a single crystal of synthetic diamond. The structure of the deposited film with the thickness up to 10 μm with high-quality morphology is investigated with an optical microscope as well as using the methods of the Raman scattering and scanning electron microscopy.