Abstract: An opaque, low resistivity silicon carbide and a method of making the opaque, low resistivity silicon carbide. The opaque, low resistivity silicon carbide is a free-standing bulk material that may be machined to form furniture used for holding semi-conductor wafers during processing of the wafers. The opaque, low resistivity silicon carbide is opaque at wavelengths of light where semi-conductor wafers are processed. Such opaqueness provides for improved semi-conductor wafer manufacturing. Edge rings fashioned from the opaque, low resistivity silicon carbide can be employed in RTP chambers.

Abstract: An opaque, low resistivity silicon carbide and a method of making the opaque, low resistivity silicon carbide. The opaque, low resistivity silicon carbide is doped with a sufficient amount of nitrogen to provide the desired properties of the silicon carbide. The opaque, low resistivity silicon carbide is a free-standing bulk material that may be machined to form furniture used for holding semi-conductor wafers during processing of the wafers. The opaque, low resistivity silicon carbide is opaque at wavelengths of light where semi-conductor wafers are processed. Such opaqueness provides for improved semi-conductor wafer manufacturing. Edge rings fashioned from the opaque, low resistivity silicon carbide can be employed in RTP chambers.

Abstract: A wafer holding apparatus composed of a plurality of rods joined at opposite ends by endplates. Each rod at each end is secured to the endplates by a mechanical dovetail joint. The dovetail joint secures the rods to the endplates without the need for sealing or coating agents. Also , auxiliary mechanical components such as nuts and bolts to secure the joint components need not be employed to secure the joint. Each rod has multiple grooves or slits for placing multiple semiconductor wafers that are to be processed in processing chambers. The wafer holding apparatus is oxidation resistant, chemical resistant and thermal shock resistant.

Abstract: The machinability of water-clear zinc sulfide articles produced by chemical vapor deposition and high temperature, high isostatic pressure (HIP) treatment is enhanced by extending the time over which the article is cooled following the HIP treatment. The resulting low stress, water-clear zinc sulfide articles can be more accurately finished/machined to precise shapes, such as are required in optical applications, than was previously possible.

Abstract: A chemical vapor deposited, p phase polycrystalline silicon carbide having a high thermal conductivity and reduced stacking faults. The silicon carbide is synthesized under specific conditions using hydrogen gas and methyltrichlorosilane gas as reactants. The thermal conductivity of the silicon carbide is sufficiently high such that it can be employed as parts of apparatus and components of electrical devices where a high heat load is generated. Such components may include active thermoelectric coolers, heat sinks and fans.

Abstract: Free standing articles of chemical vapor deposited silicon carbide with electrical resistivities of less than 0.9 ohm-cm are provided without substantially degrading its thermal conductivity or other properties.

Abstract: The machinability of water-clear zinc sulfide articles produced by chemical vapor deposition and high temperature, high isostatic pressure (HIP) treatment is enhanced by extending the time over which the article is cooled following the HIP treatment. The resulting low stress, water-clear zinc sulfide articles can be more accurately finished/machined to precise shapes, such as are required in optical applications, than was previously possible.

Abstract: The machinability of water-clear zinc sulfide articles produced by chemical vapor deposition and high temperature, high isostatic pressure (HIP) treatment is enhanced by extending the time over which the article is cooled following the HIP treatment. The resulting low stress, water-clear zinc sulfide articles can be more accurately finished/machined to precise shapes, such as are required in optical applications, than was previously possible.

Abstract: A method of bonding a first silicon carbide part to a second silicon carbide part is provided. The first silicon carbide part provides a receiving female joint member and the second silicon carbide part provides an insertion male joint member. The male and female members each have facing sidewalls substantially parallel to a direction in which the male member is inserted into the female member. The male and female joint members are configured to provide an average gap(s) between the facing sidewalls of the joint members which is up to about 0.003 inch (0.76 mm). The female joint member further has reservoir means for containing silicon when the male joint member is fully inserted into the female joint member, the reservoir means being in fluid communication with the gap(s). The reservoir means is filled with solid-state silicon, e.g., in powder form.

Abstract: .beta.-silicon carbide which is optically transmitting in the visible and infrared regions is produced by chemical vapor deposition. Deposition conditions are temperatures within a 1400.degree.-1500.degree. C. range, pressure 50 torr or less, H.sub.2 /methyltrichlorosilane molar ratios of 4-30 and a deposition rate of 1 .mu.m or less.

Abstract: .beta.-silicon carbide which is optically transmitting in the visible and infrared regions is produced by chemical vapor deposition. Deposition conditions are temperatures within a 1400.degree.-1500.degree. C. range, pressure 50 torr or less, H.sub.2 /methyltrichlorosilane molar ratios of 4-30 and a deposition rate of 1 .mu.m or less.

Abstract: Silicon carbide is produced by chemical vapor deposition at temperatures from 1340.degree.-1380.degree. C., deposition chamber pressures of 180-200 torr, H.sub.2 /methyltrichlorosilane ratio of 4-10 and deposition rate of 1-2 .mu.m/min. Furthermore, H.sub.2 supplied as a part of the gas stream contains less than about 1 part per million (ppm) O.sub.2 gas, and various means are provided to exclude particulate material from the deposition chamber. The silicon carbide is polishable to <5 .ANG. RMS as measured on a Talystep mechanical profiler and has a thermal conductivity of at least about 300 W/mk. The silicon carbide is particularly suitable for applications where high polishability and thermal conductivity is desired, such as hard disc drives and read/write heads of head-disc assemblies, and also optical apparatus which require a very high polish.

Abstract: Silicon carbide is produced by chemical vapor deposition at temperatures from 1340.degree.-1380.degree. C., deposition chamber pressures of 180-200 torr, H.sub.2 /methyltrichlorosilane ratio of 4-10 and deposition rate of 1-2 .mu.m/min. Furthermore, H.sub.2 supplied as a part of the gas stream contains less than about 1 part per million (ppm) O.sub.2 gas, and various means are provided to exclude particulate material from the deposition chamber. The silicon carbide is polishable to <5 .ANG. RMS as measured on a Talystep mechanical profiler and has a thermal conductivity of at least about 300 W/mk. The silicon carbide is particularly suitable for applications where high polishability and thermal conductivity is desired, such as hard disc drives and read/write heads of head-disc assemblies, and also optical apparatus which require a very high polish.

Abstract: Silicon carbide is produced by chemical vapor deposition at temperatures from 1340.degree.-1380.degree. C., deposition chamber pressures of 180-200 torr, H.sub.2 /methyltrichlorosilane ratio of 4-10 and deposition rate of 1-2 .mu.m/min. Furthermore, H.sub.2 supplied as a part of the gas stream contains less than about 1 part per million (ppm) O.sub.2 gas, and various means are provided to exclude particulate material from the deposition chamber. The silicon carbide is polishable to <5 .ANG. RMS as measured on a Talystep mechanical profiler and has a thermal conductivity of at least about 300 W/mk. The silicon carbide is particularly suitable for applications where high polishability and thermal conductivity is desired, such as hard disc drives and read/write heads of head-disc assemblies, and also optical apparatus which require a very high polish.

Abstract: A process and apparatus for the manufacture of chemical vapor deposited silicon carbide which comprises conveying the reaction gases to a triangular chemical vapor deposition cell where material is deposited by chemical vapor deposition. The triangular cell provides a large surface area for deposition while occupying a minimum amount of the furnace floor surface area. The triangular cell has the added benefit in that deposited silicon carbide is of negligible thickness at the edges thereby permitting easy separation of material with a minimum of post deposition machining.

Abstract: A process is disclosed for fabricating lightweight honeycomb type structures out of material such as silicon carbide (SiC) and silicon (S). The lightweight structure consists of a core to define the shape and size of the structure. The core is coated with an appropriate deposit such as SiC or Si to give the lightweight structure strength and stiffness and for bonding the lightweight structure to another surface. The core is fabricated from extremely thin ribs of appropriately stiff and strong material such as graphite. First, a graphite core consisting of an outer hexagonal cell with six inner triangular cells is constructed from the graphite ribs. The graphite core may be placed on the back-up side of a SiC faceplate and then coated with SiC to produce a monolithic structure without the use of any bonding agent. Cores and methods for the fabrication thereof in which the six inner triangular cells are further divided into a plurality of cells are also disclosed.

Abstract: A process to fabricate lightweigth ceramic mirrors, and in particular, silicon/silicon carbide mirrors, involves three chemical vapor deposition steps: one to produce the mirror faceplate, the second to form the lightweight backstructure which is deposited integral to the faceplate, and the third and final step which results in the deposition of a layer of optical grade material, for example, silicon, onto the front surface of the faceplate. The mirror figure and finish are fabricated into this latter material.

Abstract: A fluid dynamic method and apparatus effects the isolation of a predetermined deposition area in a hot-walled chemical vapor deposition chamber and limits the deposition to that area. The disclosed technique reduces stress and cracking in materials produced by chemical vapor deposition, prevents backside growth, and has particular utility in the fabrication by the chemical vapor deposition process of large, lightweight mirrors.

Abstract: Backside growth on substrates in a vapor deposition system has been a problem resulting in cracking of the material deposited on the substrate, making replication in a vapor deposition system difficult to achieve, and requiring post deposition machining to separate the substrate-deposit from the deposition fixture. A solution to the problem is the following: the substrate is mounted on a plurality of graphite pillars, with the pillars being bonded to the substrate as near the periphery thereof as possible. A hollow body open on one side but closed on the other, and fabricated from GRAFOIL with graphite cement used as a bonding agent, is mounted on the pillars with the open end facing the substrate. The open end of the body is pressed against the substrate and sealed with a bonding agent. This completely covers the backside of the substrate and thus prevents any vapor deposition thereon.