Abstract:
A method for producing CVD diamond film on a substrate comprised of a hydride-forming metal. The substrate provides for easy release of the CVD diamond coating formed thereon upon exposure to a hydrogen pressure. Self-supporting CVD diamond films of large dimension are easily obtained without dissolving the substrate. The substrate can be used in conventional CVD reactors.
Abstract:
Broadly, the present invention is directed to improving a chemical vapor phase deposition (CVD) method for synthesis of diamond wherein a hydrocarbon/hydrogen gaseous mixture is subjected to a combustion flame in the presence of oxygen to at least partially decompose the gaseous mixture to form CVD diamond. The improvement in process comprises subjecting said combustion flame to one or more of dielectric heating, d.c. discharge, or a.c. discharge. Dielectric heating can be accomplished by subjecting the combustion flame to microwave (MW) frequency discharge or radiofrequency (RF) discharge. By superimposing dielectric heating or d.c./a.c. discharge plasma generation on combustion flame process, the carbon utilization rate of the combustion flame process should improve substantially. As noted above, given the low carbon utilization rate for combustion flame techniques already, small percentage improvements in the carbon utilization rates translate into substantial cost savings in generation of CVD diamond by such combustion flame technique.
Abstract:
A stress relieved CVD diamond is produced by annealing said CVD diamond at a temperature above about 1100 to about 2200 degrees Centigrade in a non-oxidizing atmosphere at a low pressure or vacuum and for a suitable short period of time which decreases with increasing annealing temperature so as to prevent graphitization of said diamond.
Abstract:
Diamond is produced by chemical vapor deposition on a substrate by hot filament activation of a hydrogen-hydrocarbon gas mixture. An edge of the substrate faces the filament at a distance; therefrom up to about 1 mm. and preferably about 0.3-0.7 mm., and the substrate is moved relative to the filament to maintain this spacing as diamond forms thereon. Diamond formation proceeds at an improved rate, and in single crystal configuration under certain conditions.
Abstract:
Single-crystal diamond consisting of isotopically pure carbon-12 or carbon-13 has been found to have a thermal conductivity higher than that of any substance previously known, typically at least 40% higher than that of naturally occurring IIA diamond. It may be prepared by a method comprising comminution of diamond of high isotopic purity, such as that obtained by low pressure chemical vapor deposition employing an isotopically pure hydrocarbon in combination with hydrogen, followed by conversion of the comminuted diamond to single-crystal diamond under high pressure conditions.
Abstract:
Surgery is performed with pulsed heat means that selectively destroys tissue in a region within a patient. The size of the region destroyed is dependent upon the frequency of the pulses of the pulsed heat means and thermal conductivity of the tissue of the patient. The pulsed heat means can be a coherent optical source that is guided by laser fiber to the tissue to be destroyed. In another embodiment the pulsed heat means is a focussed ultrasound transducer that dissipates ultrasonic energy at a focal point within the region of tissue to be destroyed. A magnetic resonance imaging system employing a temperature sensitive pulse sequence creates an image of the tissue and the region being heated to allow a surgeon to alter the position of the pulsed heat means or vary the pulse frequency.
Abstract:
A plural substrate CVD apparatus for diamond crystal production utilizes spaced apart vertical, parallel, planar substrate panels with an electrical (direct current, D.C.) resistance filament heater therebetween. A hydrogen-hydrocarbon gas mixture flows between panels to come into contact with the heater and the panels to cause diamond crystal nucleation and growth on the substrate panels. The apparatus includes means for maintaining the spaced relationship of the heater from the substrate surfaces, comprising a rod member attached to one end of the heater and tensioned by a cable passing over a pulley member and attached to a weight.
Abstract:
A conductor is provided through a narrow bore hole of a wafer. The hole has a length-to-diameter ratio in excess of six. The conductor is formed by condensation of metal vapor generated at the bottom of said hole by a spark. The spark is generated between a vaporizable metal at the bottom of the hole and a thin electrode disposed above the hole from a conventional automobile coil and battery operating through a mercury switch.
Abstract:
In the electromigration process, liquid metal inclusions are migrated into or through bodies of semiconductor material by an electrical potential gradient driving force. The method of this invention provides anode and cathode connections generally useful in the practice of electromigration and connections which are especially useful in circumventing the adverse effects of several types of rectifying junctions encountered in the practice of electromigration.
Abstract:
A glass wafer having high aspect ratio holes passing therethrough is provided with metal conductors in the holes as feedthroughs. First, the wafer is processed to line the holes with a thin electron-conducting layer of metal. Next, a layer of the same or different metal is applied over the first metal layer providing the requisite feedthrough electrical conductivity for each hole. Preferably, the glass contains lead oxide, the first metal layer is lead and the next layer is copper.