Abstract: A plasma reactor (1) especially for diamond-CVD (chemical vapor deposition) or, for example, plasma surface treatment or plasma etching is provided. The plasma reactor (1) includes a reactor housing (2) designed as resonator, to which is attached a high-frequency coaxial line (5) connected with a high-frequency generator (6) for irradiation of microwaves. Located in the reactor housing is a substrate holder (3) for a substrate to be coated. A vacuum-tight window (12) of microwave-permeable material is positioned in a transition area from the coaxial line (5) to the reactor housing (2) and the reactor housing includes connections (10, 11) for supplying and removing process gas. The microwave window (12) is essentially ring-shaped. As a result, the coupling is distributed over a large surface so that high microwave power levels can be coupled without high electric field intensities developing at the microwave window and thus without the danger of window discharge.

Abstract: The invention concerns a diamond body designed to enable thermal contacting with at least one source of heat (30) and presenting at least one recess (13, 15) defining an angular position in relation to the mechanical tensions generated by said or any source of heat (30). Consequently, the mechanical tensions generated at various temperatures, either, for example, by various expansion coefficients of the diamond body (12) or by the source of the heat (30) featured by one semi-conductor component, are at least partly compensated, resulting in the possibility to take advantage of the exceptional thermoconductive capacity and insulating characteristics of the diamond, including diamond bodies (12) of a relatively big size.

Abstract: A plasma reactor for generating and maintaining plasma. The plasma reactor has a resonant cavity whose cross-section tapers in summit regions in which the wall of the resonant cavity is closed to such an extent that an excited field mode in the region of the cross-sectional tapered portions displays main peaks whose maximum field intensity is increased relative to the field intensity of adjacent secondary peaks. A reaction unit is provided in the region of a main peak with a substrate which is to be processed and which can be coated in the gas phase of the plasma. As a result of the field intensity distribution brought about by a resonant cavity of the given shape, with main peaks which are greatly increased with respect to secondary peaks, process parameters such as gas pressure and coupled electromagnetic power can be selected very largely independently of one another when the plasma is in a stable situation, without the plasma igniting undesirably in the region of the secondary peaks.