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Title: Silicon carbide diffusion furnace components
Claims: What is claimed is: 1. A system for a semi-conductor diffusion furnace comprising a process tube, a paddle of a size and configuration that will allow the paddle to traverse said process tube, and at least one boat supportable on said paddle, wherein said process tube, paddle and boat consist essentially of a sintered silicon carbide matrix containing 5 to 30% by weight of high purity silicon metal, said silicon metal rendering said tube, paddle and boat gas impervious. 2. The process tube, paddle, and boat of claim 1 wherein the grain size characteristic of said sintered silicon carbide is bimodal, and resulting from the sintering of silicon carbide powder that is made up of approximately 50% by weight of silicon carbide having an average particle size of 0.1 to 8 microns, and 50% by weight of silicon carbide having an average particle size of from 30 to 170 microns, and said silicon metal is at least 99% pure. 3. The process tube, paddle,, and boat of claim 1 wherein said high purity silicon metal fills at least the external porosity of those surfaces of said silicon carbide process tube, paddle and boat that will be subjected to the internal environment of the process tube. 4. The process tube, paddle, and boat of claim 1 wherein said high purity silicon metal substantially impregnates the sintered silicon carbide. 5. In a semi-conductor diffusion furnace, a process tube consisting essentially of a sintered silicon carbide matrix rendered impervious by impregnation of at least the inner surface of said process tube with silicon metal, said silicon metal being present in the range of 5 to 30% by weight and having purity of not less than 99% silicon. 6. In a semi-conductor diffusion furnace, a paddle consisting essentially of a sintered silicon carbide matrix rendered impervious by at least partial impregnation of all surfaces thereof with silicon metal, said silicon metal being present in the range of 5 to 30% by weight and having a purity of at least 99% silicon. 7. In a semi-conductor diffusion furnace, a boat consisting essentially of a sintered silicon carbide matrix rendered impervious by at least partial impregnation of all surfaces thereof with silicon metal, said silicon metal being present in the range of 5 to 30% by weight and having a purity of at least 99% silicon. 8. In a semi-conductor diffusion furnace a gas impervious process tube, boat and paddle, said process tube, boat, and paddle consisting essentially of from 70 to 95% by weight of a sintered recrystallized silicon carbide matrix which is 99 to 100% pure silicon carbide, impregnated with 5 to 30% by weight of silicon metal which is at least 99.9% pure silicon, the composite of silicon carbide and silicon having a modulus of rupture at room temperature of at least 10,000 p.s.i. (700 kg./cm..sup.2). 9. A system for a semi-conductor diffusion furnace comprising a process tube, a mating paddle, and at least one boat supportable on said paddle, wherein said process tube, paddle and boat consist essentially of a sintered silicon carbide matrix impregnated with 5 to 30% by weight of silicon metal which is at least 99.9% pure, said silicon metal impregnant rendering said process tube, paddle, and boat gas impervious, and wherein said process tube has a cone shaped end terminating in a ball joint suitable for attachment to an apparatus for introduction of gas into said process tube. Other info: Inventors: Alliegro, Richard A. (Holden, MA, US) Coes, Samuel H. (Northborough, MA, US) Application Number: 530083 Filing Date: 1974-12-06 Publication_date: 1976-04-20 Assignee: Norton Company (Worcester, MA) Primary Class(es): 432/253 206/454, 206/564, 432/258, 432/259 Other Classes: US Patent Ref:
Other Refs: Primary Examiner: Camby, John J. Assistant Examiner: Attorney: Loiselle, Jr.; Arthur A. |
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