Abstract: A two-stage microwave plasma CVD process is disclosed for making a CVD diamond material, substantially free of voids, which has an average crystallite size greater than about 15 microns, a maximum intensity of the diamond Raman peak in counts/sec divided by the intensity of photoluminescence at 1270 cm.sup.-1 greater than about 3, a Raman sp.sup.3 full width half maximum less than about 6 cm.sup.-1 and a diamond-to-graphite Raman ratio greater than about 25.

Abstract: The present invention comprises an article formed from a plurality of diamond particles and non-diamond particles compatible with diamond deposition preformed into a desired shape. Each of the particles has first surface regions in contact with immediately adjacent other ones of the particles, and second surface regions spaced apart from the immediately adjacent other ones of said particles to define boundaries of inter-particle voids between the immediately adjacent ones of the particles. The voids are infiltrated with high thermal conductivity CVD diamond material continuously coating the second surface regions of the particles and comprising merged growth fronts from the second surface regions of individual immediately adjacent ones of the particles into the inter-particle voids.

Abstract: A block of dielectric material having a long axis and a short axis and having low losses at a selected microwave frequency and a dielectric constant selected to produce a desired degree of phase modulation is mounted on a rotatable shaft in an orientation perpendicular to the long and short axes and arranged inside a waveguide feeding a CVD reactor containing a plasma species The block is spun by a rotational force applied to the shaft at an angular acceleration such that the two axes of the block successively intersect the axis of the waveguide within the decay period of the plasma species. The frequency of phase modulation can be varied by changing the angular acceleration of the shaft, and the amplitude of the phase modulation can be varied by changing the ratio of block length to thickness and/or by selecting a material with higher dielectric constant. The incident microwave power may be modulated as a function of angular position of the spin shaft.

Abstract: A process is provided for making a semiconductor element comprising a single-crystal layer of silicon on a diamond insulator.

Abstract: Processes are provided for consolidating diamond particles into a mechanically stable diamond mass, called a diamond ceramic. A compacted aggregation of diamond particles is subjected to low pressure PECVD conditions in the presence of atomic hydrogen, with or without a carbon source gas, whereby a mechanically stable diamond ceramic is formed substantially devoid of interstitial spaces.

Abstract: A process is provided for forming synthetic diamond by vapor deposition of a carbon gas source in the presence of atomic hydrogen on a substrate contained in a fluidized bed. The diamond may be overcoated by vapor deposition of a non-diamond material.

Abstract: A method is provided for producing thin diamond films which are useful as X-ray transmissive elements.

Abstract: Processes are provided for consolidating diamond particles into a mechanically stable diamond mass, called a diamond ceramic. A compacted aggregation of diamond particles is subjected to low pressure PECVD conditions in the presence of atomic hydrogen, with or without a carbon source gas, whereby a mechanically stable diamond ceramic is formed substantially devoid of interstitial spaces.

Abstract: Methods are provided for suppressing the growth of graphite and other non-diamond carbon species during the low pressure deposition of carbon to form diamond. In one method, the graphite or other non-diamond carbon species is vaporized using incident radiative energy sufficient to vaporize graphite but insufficient to damage the substrate. In another embodiment the graphite or other non-diamond carbon species is selectively photolyzed, such as, by use of laser energy of appropriate wavelength.