Patents Assigned to Group IV Semiconductor Inc.
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Publication number: 20120322181Abstract: A method is disclosed for deposition of thin film dielectrics, and in particular for chemical vapour deposition of nano-layer structures comprising multiple layers of dielectrics, such as, silicon dioxide, silicon nitride, silicon oxynitride and/or other silicon compatible dielectrics. The method comprises post-deposition surface treatment of deposited layers with a metal or semiconductor source gas, e.g. a silicon source gas. Deposition of silicon containing dielectrics preferably comprises silane-based chemistry for deposition of doped or undoped dielectric layers, and surface treatment of deposited dielectric layers with silane. Surface treatment provides dielectric layers with improved layer-to-layer uniformity and lateral continuity, and substantially atomically flat dielectric layers suitable for multilayer structures for electroluminescent light emitting structures, e.g. active layers containing rare earth containing luminescent centres.Type: ApplicationFiled: March 1, 2010Publication date: December 20, 2012Applicant: GROUP IV SEMICONDUCTOR INC.Inventors: Jean-Paul Noel, Ming Li
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Patent number: 8232611Abstract: Improved high quality gate dielectrics and methods of preparing such dielectrics are provided. Preferred dielectrics comprise a rare earth doped dielectric such as silicon dioxide or silicon oxynitride. In particular, cerium doped silicon dioxide shows an unexpectedly high charge-to-breakdown QBD, believed to be due to conversion of excess hot electron energy as photons, which reduces deleterious hot electron effects such as creation of traps or other damage. Rare earth doped dielectrics therefore have particular application as gate dielectrics or gate insulators for semiconductor devices such as floating gate MOSFETs, as used in as flash memories, which rely on electron injection and charge transfer and storage.Type: GrantFiled: June 14, 2010Date of Patent: July 31, 2012Assignee: Group IV Semiconductor, Inc.Inventors: Carla Miner, Thomas MacElwee, Marwan Albarghouti
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Patent number: 8198638Abstract: A light emitting device structure, wherein the emitter layer structure comprises one or more device wells defined by thick field oxide regions, and a method of fabrication thereof are provided. Preferably, by defining device well regions after depositing the emitter layer structure, emitter layer structures with reduced topography may be provided, facilitating processing and improving layer to layer uniformity. The method is particularly applicable to multilayer emitter layer structures, e.g. comprising a layer stack of active layer/drift layer pairs. Preferably, active layers comprise a rare earth oxide, or rare earth doped dielectric such as silicon dioxide, silicon nitride, or silicon oxynitride, and respective drift layers comprise a suitable dielectric, preferably silicon dioxide, of an appropriate thickness to control excitation energy. Pixellated light emitting structures, or large area, high brightness emitter layer structures, e.g.Type: GrantFiled: July 14, 2010Date of Patent: June 12, 2012Assignee: Group IV Semiconductor Inc.Inventors: Thomas MacElwee, Alasdair Rankin
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Patent number: 8093604Abstract: An engineered structure of a light emitting device comprises multiple layers of alternating active and buffer materials disposed between AC or DC electrodes, which generate an electric field. The active layers comprise luminescent centers, e.g. group IV semiconductor nanocrystals, in a host matrix, e.g. a wide bandgap semiconductor or dielectric material such as silicon dioxide or silicon nitride. The buffer layers are comprised of a wide bandgap semiconductor or dielectric material, and designed with a thickness, in the direction of an applied electric field, that ensures that electrons passing therethrough picks up enough energy to excite the luminescent centers in the adjacent active layer at an excitation energy to emit light efficiently at a desired wavelength.Type: GrantFiled: December 21, 2006Date of Patent: January 10, 2012Assignee: Group IV Semiconductor, Inc.Inventors: George Chik, Thomas MacElwee, Iain Calder, Steven E. Hill
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Patent number: 8089080Abstract: Electroluminescent (EL) light emitting structures comprises one or more active layers comprising rare earth luminescent centers in a host matrix for emitting light of a particular color or wavelength and electrodes for application of an electric field and current injection for excitation of light emission. The host matrix is preferably a dielectric containing the rare earth luminescent centers, e.g. rare earth doped silicon dioxide, silicon nitride, silicon oxynitrides, alumina, dielectrics of the general formula SiaAlbOcNd, or rare earth oxides. For efficient impact excitation, corresponding drift layers adjacent each active layer have a thickness related to a respective excitation energy of an adjacent active layer. A stack of active layers emitting different colors may be combined to provide white light. For rare earth species having a host dependent emission spectrum, spectral emission of the stack may be tuned by appropriate selection of a different host matrix in successive active layers.Type: GrantFiled: July 23, 2009Date of Patent: January 3, 2012Assignee: Group IV Semiconductor, Inc.Inventors: Iain Calder, Carla Miner, George Chik, Thomas Macelwee
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Patent number: 7923925Abstract: Electroluminescent (EL) devices structures are provided comprising a hot electron stopper layer structure to capture hot electrons and dissipate their energy, thereby reducing damage to the transparent conducting oxide (TCO) layer and reducing other hot electron effects, such as charging effects, which impact reliability of EL device structures. The stopper layer structure may comprise a single layer or multiple layers provided between the TCO electrode layer and the emitter structure, and may also function to reduce diffusion or chemical interactions between the TCO and the emitter layer structure. Optionally, stopper layers may also be provided within the emitter structure. Suitable stopper layer materials are wideband gap semiconductors or dielectrics, preferably transparent at wavelengths emitted by the EL device characterized by high impact ionization rates, and/or high relative permittivity relative to adjacent layers of the emitter structure.Type: GrantFiled: November 19, 2008Date of Patent: April 12, 2011Assignee: Group IV Semiconductor, Inc.Inventors: Thomas MacElwee, Jean-Paul Noel, Dean Ducharme, Yongbao Xin
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Patent number: 7923288Abstract: A thin film electro-luminescent device (TFEL) includes an active layer made of a direct bandgap semiconductor material, e.g. zinc oxide, doped with exciton binding centers, such as aluminum, in small amounts, e.g. 0.001 at % to 30.0 at %. The exciton binding centers prevent free excitons, created by impact ionization, from diffusing toward and recombining at native defect centers. To provide a columnar structure, a polycrystalline seed layer is deposited first to provide a template, followed by the deposition of an overlying layer forming columns in accordance with the template.Type: GrantFiled: September 10, 2008Date of Patent: April 12, 2011Assignee: Group IV Semiconductor, Inc.Inventor: Jean-Paul Noel
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Patent number: 7888686Abstract: A light emitting device includes an active layer structure, which has one or more active layers with luminescent centers, e.g. a wide bandgap material with semiconductor nano-particles, deposited on a substrate. For the practical extraction of light from the active layer structure, a transparent electrode is disposed over the active layer structure and a base electrode is placed under the substrate. Transition layers, having a higher conductivity than a top layer of the active layer structure, are formed at contact regions between the upper transparent electrode and the active layer structure, and between the active layer structure and the substrate. Accordingly the high field regions associated with the active layer structure are moved back and away from contact regions, thereby reducing the electric field necessary to generate a desired current to flow between the transparent electrode, the active layer structure and the substrate, and reducing associated deleterious effects of larger electric fields.Type: GrantFiled: January 16, 2008Date of Patent: February 15, 2011Assignee: Group IV Semiconductor Inc.Inventors: George Chik, Thomas MacElwee, Iain Calder, E. Steven Hill
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Patent number: 7839467Abstract: The present invention replaces conventional lighting devices, such as incandescent lamps, fluorescent lamps, and LED lamps, with an integrated electro-luminescent film structure, subdivided into electrically isolated micro-panels. Ideally, the electro-luminescent structure comprises separate red, green and blue micro-panels providing a full range of color adjustment. Alternatively, the electro-luminescent film structure includes stacked groups of layers, in which each group emits a different color and is independently controllable.Type: GrantFiled: October 16, 2009Date of Patent: November 23, 2010Assignee: Group IV Semiconductor Inc.Inventors: Carla Miner, Thomas MacElwee, Stephen Naor, Howard Tweddle
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Patent number: 7800117Abstract: A light emitting device includes an active layer structure, which has one or more active layers with luminescent centers, e.g. a wide bandgap material with semiconductor nano-particles, deposited on a substrate. For the practical extraction of light from the active layer structure, a transparent electrode is disposed over the active layer structure and a base electrode is placed under the substrate. Transition layers, having a higher conductivity than a top layer of the active layer structure, are formed at contact regions between the upper transparent electrode and the active layer structure, and between the active layer structure and the substrate. Accordingly the high field regions associated with the active layer structure are moved back and away from contact regions, thereby reducing the electric field necessary to generate a desired current to flow between the transparent electrode, the active layer structure and the substrate, and reducing associated deleterious effects of larger electric fields.Type: GrantFiled: December 21, 2006Date of Patent: September 21, 2010Assignee: Group IV Semiconductor, Inc.Inventors: George Chik, Thomas MacElwee, Iain Calder, E. Steven Hill
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Patent number: 7679102Abstract: A solid state light emitting device comprises one or more active layers comprising semiconductor nano-particles in a host matrix, e.g. silicon nano-particles in silicon dioxide or silicon nitride. The incorporation of carbon in the active layers provides a great improvement in performance through shortened decay time and enhance emission spectra, as well as reliability and lifetime. The emission wavelengths from the nano-particles can be made to correspond to the quantization energy of the semiconductor nano-particles, which allows the entire visible range of the spectrum be covered. Ideally an engineered structure of alternating active and buffer material layers are disposed between AC or DC electrodes, which generate an electric field.Type: GrantFiled: December 21, 2006Date of Patent: March 16, 2010Assignees: Group IV Semiconductor, Inc., McMaster UniversityInventors: George Chik, Thomas MacElwee, Iain Calder, E. Steven Hill, Peter Mascher, Jacek Wojcik
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Patent number: 7616272Abstract: The present invention replaces the conventional cold cathode fluorescent tubes used in backlighting units of liquid crystal displays with an integrated electro-luminescent film structure, subdivided into electrically isolated micro-panels. Ideally, the electro-luminescent structure comprises separate red, green and blue micro-panels providing full color capabilities. Alternatively, the electro-luminescent film structure includes stacked groups of layers, in which each group emits a different color and is independently controllable.Type: GrantFiled: August 17, 2007Date of Patent: November 10, 2009Assignee: Group IV Semiconductor Inc.Inventors: Carla Miner, Thomas MacElwee, Stephen Naor, Howard Tweddle
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Publication number: 20080246046Abstract: A light emitting device includes an active layer structure, which has one or more active layers with luminescent centers, e.g. a wide bandgap material with semiconductor nano-particles, deposited on a substrate. For the practical extraction of light from the active layer structure, a transparent electrode is disposed over the active layer structure and a base electrode is placed under the substrate. Transition layers, having a higher conductivity than a top layer of the active layer structure, are formed at contact regions between the upper transparent electrode and the active layer structure, and between the active layer structure and the substrate. Accordingly the high field regions associated with the active layer structure are moved back and away from contact regions, thereby reducing the electric field necessary to generate a desired current to flow between the transparent electrode, the active layer structure and the substrate, and reducing associated deleterious effects of larger electric fields.Type: ApplicationFiled: January 16, 2008Publication date: October 9, 2008Applicant: GROUP IV SEMICONDUCTOR INC.Inventors: George Chik, Thomas MacElwee, Iain Calder, E. Steven Hill
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Patent number: 7122842Abstract: A light emitting assembly comprising a solid state device coupleable with a power supply constructed and arranged to power the solid state device to emit from the solid state device. A series of rare-earth doped silicon and/or silicon carbide nanocrystals that are either combined in a single layer or in individual layers that produce the required Red, Green, and Blue (RGB) emission to form a white light.Type: GrantFiled: July 22, 2004Date of Patent: October 17, 2006Assignee: Group IV Semiconductor Inc.Inventor: Steven E. Hill
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Patent number: 7081664Abstract: The invention provides a doped semiconductor powder comprising nanocrystals of a group IV semiconductor and a rare earth element, the rare earth element being dispersed on the surface of the group IV semiconductor nanocrystals. The invention also provides processes for the preparation of the above doped semiconductor powder, and a composite material comprising a matrix in which is dispersed a doped semiconductor powder.Type: GrantFiled: January 22, 2004Date of Patent: July 25, 2006Assignee: Group IV Semiconductor Inc.Inventor: Steven E. Hill
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Publication number: 20060065943Abstract: Group IV semiconductor nanocrystal doped with rare earths or other light emitting metal to form alternating current solid-state devices that can be designed to operate at a variety of voltages including line voltages. The semiconductor nanocrystals are preferably silicon, silicon carbide, germanium or germanium carbide, and the electric luminescent device may have an upper and lower thin coat of a semiconductor nanocrystal glass material in turn connected to alternating current electrodes. The present invention enables one to fabricate a solid-state light that can use standard fixtures, e.g. Edison type, and standard AC voltages and frequencies for use in houses and businesses without refurbishing the installed lighting fixtures.Type: ApplicationFiled: September 16, 2005Publication date: March 30, 2006Applicant: GROUP IV SEMICONDUCTOR INC.Inventor: E. Hill