Patents by Inventor Lawrence K. White
Lawrence K. White has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5958793Abstract: A method of etching an opening having tapered wall in a layer of silicon carbide (SiC) includes forming a layer of a resist on the SiC layer. An opening having tapered wall is formed in the resist layer so as to expose a portion of the SiC layer. The exposed portion of the SiC layer is then exposed to a plasma of a gas containing carbon and fluorine to etch an opening through the SiC layer with the opening having tapered walls. If a layer of a glass is provided under the SiC layer, the plasma will also etch through the glass layer to provide an opening in the glass layer having tapered walls.Type: GrantFiled: December 24, 1997Date of Patent: September 28, 1999Assignee: Sarnoff CorporationInventors: Vipulkumar K. Patel, Lawrence K. White, Lawrence A. Goodman
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Patent number: 4810617Abstract: An improved electron beam resist structure comprises an organic planarizing layer which has been treated with an ion beam for a time sufficient to render it conductive and an electron beam resist layer thereover. The electron beam resist layer is preferably oxygen plasma resistant. When the resist layer is not resistant to oxygen plasma and it is desired to develop the planarizing layer by oxygen plasma, the structure additionally includes a thin hard mask layer, suitably of silicon dioxide, interposed between the conductive planarizing layer and the resist layer.Type: GrantFiled: May 12, 1987Date of Patent: March 7, 1989Assignee: General Electric CompanyInventors: Lawrence K. White, Richard Brown
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Patent number: 4784936Abstract: An improved process for forming multilayer resist structures for lithographic processing of a substrate having topographical features is provided. The structures are comprised of a resist layer having thereover a layer of poly(vinyl pyrrolidone). When the resist layer is a photoresist, the subject structures may optionally contain an absorptive layer directly overlying the substrate and/or a layer of contrast enhancement material overlying the planarizing layer. The poly(vinyl pyrrolidone) optionally contains from about 0.05 to about 0.1 percent by weight of a suitable surfactant, suitably a nonionic surfactant.Type: GrantFiled: September 9, 1986Date of Patent: November 15, 1988Assignee: General Electric CompanyInventors: Lawrence K. White, Nancy A. Miszkowski
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Patent number: 4741926Abstract: Nonuniform topographical features on a substrate are effectively coated for lithographic processing by spin-coating with a suitable resin material in a dual spin cycle. The coating material is initially spin-coated onto the substrate at not less than 4000 rpm, preferably from 6000 to 8000 rpm, until build-up of the coating is detectable on a side wall of a topographical feature facing the centrifugal center of the spinning substrate. The spin speed is immediately reduced to less than 4000 rpm, preferably from about 1000 to 3500 rpm, and spinning is continued for a time sufficient to dry the coating. The subject process is particularly suitable for coating a substrate having nonuniform topographical features with a planarizing material.Type: GrantFiled: October 29, 1985Date of Patent: May 3, 1988Assignee: RCA CorporationInventors: Lawrence K. White, Nancy A. Miszkowski
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Patent number: 4737033Abstract: A substrate includes an alignment key for forming features in or on both surfaces of the substrate which are in alignment with each other. The alignment key includes a plurality of adjacent but spaced apart small openings formed in one surface of the substrate through a P-type region at said one surface and a large opening extending through the substrate from its other surface to the P-type region. The larger opening exposes the smaller openings so that they can be seen from both sides of the substrate. The smaller openings are arranged to form an alignment mark.Type: GrantFiled: October 7, 1986Date of Patent: April 12, 1988Assignee: General Electric Co.Inventors: Anton G. Moldovan, Frank V. L. Shallcross, Lawrence K. White
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Patent number: 4702993Abstract: An improved electron beam resist structure comprises an organic planarizing layer which has been treated with an ion beam for a time sufficient to render it conductive and an electron beam resist layer thereover. The electron beam resist layer is preferably oxygen plasma resistant. When the resist layer is not resistant to oxygen plasma and it is desired to develop the planarizing layer by oxygen plasma, the structure additionally includes a thin hard mask layer, suitably of silicon dioxide, interposed between the conductive planarizing layer and the resist layer.Type: GrantFiled: November 25, 1985Date of Patent: October 27, 1987Assignee: RCA CorporationInventors: Lawrence K. White, Richard Brown
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Patent number: 4618565Abstract: Multilayer photoresist recording media containing an absorptive layer are improved by forming the absorptive layer from a composition comprising PMMA or a copolymer of methylmethacrylate and methacrylic acid, certain dyes such as hydroxyazobenzoic acid or Sudan Orange G and a suitable solvent. The dyes are insoluble in the solvent of an overlying photoresist layer. The media are substantially free of loss of resolution due to dissolution of the dye into the photoresist layer.Type: GrantFiled: June 5, 1985Date of Patent: October 21, 1986Assignee: RCA CorporationInventors: Lawrence K. White, Nancy A. Miszkowski, Aaron W. Levine
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Patent number: 4609447Abstract: A method of determining the presence of alkali metal ions in a substrate comprising silicon or silicon doped with a p-type conductivity modifier is provided. The substrate to be tested is etched in a tetrafluoromethane/oxygen plasma and the etch rate is compared against that of similar substrates containing known concentrations of alkali metal ions. The etch rate will increase with increasing alkali metal concentration. The subject method is particularly useful in determining the level of alkali metal ion contamination during multistep processing of the above-named substrates.Type: GrantFiled: January 22, 1985Date of Patent: September 2, 1986Assignee: RCA CorporationInventors: Lawrence K. White, Jen-shen Maa
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Patent number: 4600597Abstract: A method for determining the contour of a spin-coated thin film of material, such as a photoresist solution, on an uneven topography, such as a patterned semiconductor wafer, utilizes a pattern of features as isolated, raised lines of different widths. The pattern serves to provide frequency weighted parameters used to estimate the coating conformality on both simple and complex topographies. One parameter indicating the contour is independent of coating thickness and the other parameter suggests the range of feature-to-feature interaction inherent in complex topographies. The pattern is useful as a "knock-out" portion of a product wafer to monitor the contour of the coating deposited by spun-coated process steps.Orienting the line pattern in radial and tangential position reveals coating thickness relationships dependent on feature orientation with respect to the centrifugal center of the substrate.Type: GrantFiled: October 29, 1984Date of Patent: July 15, 1986Assignee: RCA CorporationInventors: Lawrence K. White, Nancy A. Miszkowski
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Patent number: 4532002Abstract: An improved method of forming a patterned layer of metallization on a substrate having topographical features is provided. A layer of a polymeric lift-off material is initially spin-coated onto the substrate, and a layer of a polymeric planarizing material spin-coated thereover. The dry etch rate of the lift-off layer is at least 1.2 times faster than that of the planarizing layer thereby forming a reverse slope wall profile in openings etched through both layers. A patterned hardmask layer is suitably used to dry etch the planarizing and lift-off layers, preferably in an oxygen-containing plasma. A layer of metallization is then deposited thereon. The metal in the openings is discontinuous from that deposited over the hardmask because of the reverse slope wall profile of the openings in the planarizing layers. The structure is then contacted with an organic solvent which penetrates to the base of the lift-off layer, again due to the reverse slope wall profile.Type: GrantFiled: April 10, 1984Date of Patent: July 30, 1985Assignee: RCA CorporationInventor: Lawrence K. White
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Patent number: 4498775Abstract: A device for monitoring gap deviations in an optical printer comprises a mask having a plurality of closely-spaced differently-sized apertures. Actinic light passing through the aperture to a photoresist surface develops a pattern of diffraction-induced images in the photoresist surface. Each image is uniquely shaped according to its associated aperture size, gap dimension, light wavelength and photoresist characteristics. An indexing parameter (.DELTA..nu.) is used to relate the pattern of images developed to gapping or focusing deviations in the system. Either proximity or projection printers can be used.Type: GrantFiled: February 17, 1982Date of Patent: February 12, 1985Assignee: RCA CorporationInventor: Lawrence K. White
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Patent number: 4470871Abstract: An improved method of etching a layer of organic material on a sustrate by oxygen plasma or oxygen reactive ion etching is disclosed. The surface of the layer is flood exposed with a plasma including a fluorine species for a time sufficient to significantly reduce the etch rate thereof in the oxygen etch. A patterned mask is then formed on the layer and the exposed portion etched. The subject method produces vertical walls in the etch profile with substantially no rounding of the top edge.Type: GrantFiled: December 27, 1983Date of Patent: September 11, 1984Assignee: RCA CorporationInventors: Lawrence K. White, Metodi Popov
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Patent number: 4427713Abstract: A method of planarizing a light sensitive coating on a substrate having topographical features is provided. The coating which comprises a novolak resin and a diazoquinone sensitizer is exposed to actinic radiation to react substantially all of the sensitizer and then heated by applying heat to the surface of the substrate opposite the coating.Type: GrantFiled: January 17, 1983Date of Patent: January 24, 1984Assignee: RCA CorporationInventors: Lawrence K. White, Metodi Popov
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Patent number: 4319954Abstract: The method involves the formation of conductive, polycrystalline silicon lines and vias by the conversion of amorphous silicon in contact with the underlying silicon substrate through the use of a laser annealing process.Type: GrantFiled: February 27, 1981Date of Patent: March 16, 1982Assignee: RCA CorporationInventors: Lawrence K. White, Chung P. Wu
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Patent number: 4278508Abstract: A method of detecting a cathodic corrosion site on a metallized substrate comprises depositing molecules of a pH sensitive fluorescent dye adjacent a metallic surface of the substrate, the metallic surface having a corrosion site thereon characterized by a reduction of the hydronium ion to hydrogen (2H.sup.+ +2e.sup.- .fwdarw.H.sub.2). An electrical bias is then applied across the metallic surface, and the fluorescent dye is exposed to ultraviolet (UV) radiation, whereby fluorescence is activated at the cathodic corrosion site.Type: GrantFiled: November 13, 1979Date of Patent: July 14, 1981Assignee: RCA CorporationInventors: Lawrence K. White, Robert B. Comizzoli, George L. Schnable