Patents by Inventor Douglas J. Tweet
Douglas J. Tweet 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: 7651883Abstract: An array of fully isolated multi-junction complimentary metal-oxide-semiconductor (CMOS) filterless color imager cells is provided, with a corresponding fabrication process. The color imager cell array is formed from a bulk silicon (Si) substrate without an overlying epitaxial Si layer. A plurality of color imager cells are formed in the bulk Si substrate, where each color imager cell includes a photodiode set and a U-shaped well liner. The photodiode set includes first, second, and third photodiode formed as a stacked multi-junction structure, while the U-shaped well liner fully isolates the photodiode set from adjacent photodiode sets in the array. The U-shaped well liner includes a physically interfacing doped well liner bottom and first wall. The well liner bottom is interposed between the substrate and the photodiode set, and the first wall physically interfaces each doped layer of each photodiode in the photodiode set.Type: GrantFiled: May 9, 2007Date of Patent: January 26, 2010Assignee: Sharp Laboratories of America, Inc.Inventors: Jong-Jan Lee, Douglas J. Tweet, Sheng Teng Hsu
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Patent number: 7608874Abstract: An array of fully isolated multi-junction complimentary metal-oxide-semiconductor (CMOS) filterless color imager cells is provided, together with an associated fabrication method. The method provides a bulk silicon (Si) substrate. A plurality of color imager cells are formed, either in the Si substrate, or in a single epitaxial Si layer formed over the substrate. Each color imager cell includes a photodiode set with a first, second, and third photodiode formed as a stacked multi-junction structure. A U-shaped (in cross-section) well liner, fully isolates the photodiode set from adjacent photodiode sets in the array. For example, each photodiode is formed from a p doped Si layer physically interfaced to a first wall. A well bottom physically interfaces to the first wall, and the p doped Si layer of the third, bottom-most, photodiode is part of the well bottom. Then, the photodiode sets may be formed from an n/p/n/p/n/p or n/p/p?/p/p?/p layered structure.Type: GrantFiled: January 24, 2007Date of Patent: October 27, 2009Assignee: Sharp Laboratories of America, Inc.Inventors: Jong-Jan Lee, Douglas J. Tweet, Sheng Teng Hsu
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Patent number: 7598108Abstract: A thermal expansion interface between silicon (Si) and gallium nitride (GaN) films using multiple buffer layers of aluminum compounds has been provided, along with an associated fabrication method. The method provides a (111) Si substrate and deposits a first layer of AlN overlying the substrate by heating the substrate to a relatively high temperature of 1000 to 1200° C. A second layer of AlN is deposited overlying the first layer of AlN at a lower temperature of 500 to 800° C. A third layer of AlN is deposited overlying the second layer of AlN by heating the substrate to the higher temperature range. Then, a grading Al1-XGaXN layer is formed overlying the third layer of AlN, where 0<X<1, followed by a fixed composition Al1-XGaXN layer overlying the first grading Al1-XGaXN layer. An epitaxial GaN layer can then be grown overlying the fixed composition Al1-XGaXN layer.Type: GrantFiled: July 6, 2007Date of Patent: October 6, 2009Assignee: Sharp Laboratories of America, Inc.Inventors: Tingkai Li, Douglas J. Tweet, Jer-Shen Maa, Sheng Teng Hsu
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Publication number: 20090200584Abstract: A full color complementary metal oxide semiconductor (CMOS) imaging circuit is provided. The imaging circuit comprises an array of photodiodes including a plurality of pixel groups. Each pixel group supplies 3 electrical color signals, corresponding to 3 detectable colors. The circuit also includes a color filter array overlying the photodiode array employing less than 3 separate filter colors. Each pixel group may be enabled as a dual-pixel including a single photodiode (PD) to supply a first color signal and stacked PDs to supply a second and third color signal. In one aspect, the color filter array employs 1 filter color per pixel group. In another aspect, the color filter array employees 2 filter colors per pixel group. In either aspect, the color filter array forms a checkerboard pattern of color filter pixels. For example, a magenta color filter may overlie the stacked PDs of each dual-pixel, to name one variation.Type: ApplicationFiled: February 11, 2008Publication date: August 13, 2009Inventors: Douglas J. Tweet, Jong-Jan LEE
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Publication number: 20090194800Abstract: A dual-pixel full color CMOS imager is provided. The imager comprises a two-photodiode stack including an n doped substrate, a bottom photodiode, and a top photodiode. The bottom photodiode has a bottom p doped layer at a first depth overlying the substrate and a bottom n doped layer cathode overlying the bottom p doped layer. The top photodiode has a top p doped layer overlying the bottom n doped layer and a top n doped layer cathode overlying the top p doped layer. The imager further includes a single photodiode including a bottom p doped layer overlying the substrate at a third depth, where the third depth is less than, or equal to the first depth. A bottom n doped layer overlies the bottom p doped layer, a top p doped layer directly overlies the bottom n doped layer without an intervening layer, and a top n doped layer overlies the top p doped layer.Type: ApplicationFiled: October 14, 2008Publication date: August 6, 2009Inventors: Jong-Jan Lee, Jon M. Speigle, Douglas J. Tweet
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Publication number: 20090173933Abstract: A silicon/germanium (SiGe) superlattice thermal sensor is provided with a corresponding fabrication method. The method forms an active CMOS device in a first Si substrate, and a SiGe superlattice structure on a second Si-on-insulator (SOI) substrate. The first substrate is bonded to the second substrate, forming a bonded substrate. An electrical connection is formed between the SiGe superlattice structure and the CMOS device, and a cavity is formed between the SiGe superlattice structure and the bonded substrate.Type: ApplicationFiled: September 23, 2008Publication date: July 9, 2009Inventors: Jer-Shen Maa, Jinke Tang, Jong-Jan Lee, Douglas J. Tweet, Sheng Teng Hsu
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Publication number: 20090008647Abstract: A thermal expansion interface between silicon (Si) and gallium nitride (GaN) films using multiple buffer layers of aluminum compounds has been provided, along with an associated fabrication method. The method provides a (111) Si substrate and deposits a first layer of AlN overlying the substrate by heating the substrate to a relatively high temperature of 1000 to 1200° C. A second layer of AlN is deposited overlying the first layer of AlN at a lower temperature of 500 to 800° C. A third layer of AlN is deposited overlying the second layer of AlN by heating the substrate to the higher temperature range. Then, a grading Al1-XGaXN layer is formed overlying the third layer of AlN, where 0<X<1, followed by a fixed composition Al1-XGaXN layer overlying the first grading Al1-XGaXN layer. An epitaxial GaN layer can then be grown overlying the fixed composition Al1-XGaXN layer.Type: ApplicationFiled: July 6, 2007Publication date: January 8, 2009Inventors: Tingkai Li, Douglas J. Tweet, Jer-Shen Maa, Sheng Teng Hsu
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Patent number: 7470573Abstract: A method of making CMOS devices on strained silicon on glass includes preparing a glass substrate, including forming a strained silicon layer on the glass substrate; forming a silicon oxide layer by plasma oxidation of the strained silicon layer; depositing a layer of doped polysilicon on the silicon oxide layer; forming a polysilicon gate; implanting ions to form a LDD structure; depositing and forming a spacer dielectric on the gate structure; implanting and activation ions to form source and drain structures; depositing a layer of metal film; annealing the layer of metal film to form salicide on the source, drain and gate structures; removing any unreacted metal film; depositing a layer of interlayer dielectric; and forming contact holes and metallizing.Type: GrantFiled: February 18, 2005Date of Patent: December 30, 2008Assignee: Sharp Laboratories of America, Inc.Inventors: Jong-Jan Lee, Jer-Shen Maa, Douglas J. Tweet, Yoshi Ono, Sheng Teng Hsu
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Publication number: 20080315255Abstract: A method is provided for forming a matching thermal expansion interface between silicon (Si) and gallium nitride (GaN) films. The method provides a (111) Si substrate with a first thermal expansion coefficient (TEC), and forms a silicon-germanium (SiGe) film overlying the Si substrate. A buffer layer is deposited overlying the SiGe film. The buffer layer may be aluminum nitride (AlN) or aluminum-gallium nitride (AlGaN). A GaN film is deposited overlying the buffer layer having a second TEC, greater than the first TEC. The SiGe film has a third TEC, with a value in between the first and second TECs. In one aspect, a graded SiGe film may be formed having a Ge content ratio in a range of about 0% to 50%, where the Ge content increases with the graded SiGe film thickness.Type: ApplicationFiled: August 27, 2008Publication date: December 25, 2008Inventors: Jer-Shen Maa, Tingkai Li, Douglas J. Tweet, Gregory M. Stecker, Sheng Teng Hsu
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Publication number: 20080296625Abstract: A multilayer thermal expansion interface between silicon (Si) and gallium nitride (GaN) films is provided, along with an associated fabrication method. The method provides a (111) Si substrate and forms a first layer of a first film overlying the substrate. The Si substrate is heated to a temperature in the range of about 300 to 800° C., and the first layer of a second film is formed in compression overlying the first layer of the first film. Using a lateral nanoheteroepitaxy overgrowth (LNEO) process, a first GaN layer is grown overlying the first layer of second film. Then, the above-mentioned processes are repeated: forming a second layer of first film; heating the substrate to a temperature in the range of about 300 to 800° C.; forming a second layer of second film in compression; and, growing a second GaN layer using the LNEO process.Type: ApplicationFiled: June 4, 2007Publication date: December 4, 2008Inventors: Tingkai Li, Douglas J. Tweet, Jer-Shen Maa, Sheng Teng Hsu
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Publication number: 20080296616Abstract: A method is provided for forming a matching thermal expansion interface between silicon (Si) and gallium nitride (GaN) films. The method provides a (111) Si substrate that is heated to a temperature in a range of about 300 to 800° C., and a first film is formed in compression overlying the Si substrate. The first film material may be InP, SiGe, GaP, GaAs, AlN, AlGaN, an AlN/graded AlGaN (Al1?xGaxN (0<x<1)) stack, or a AlN/graded AlGaN/GaN stack. The first film is then nanoscale patterned and a lateral nanoheteroepitaxy overgrowth (LNEO) process is used to grow a first GaN layer. The above-mentioned processes are repeated, forming a second film in compression that is nanoscale patterned, and a second GaN layer is grown using the LNEO process. The first and second GaN layers are formed by heating the Si substrate to a temperature in a range of 1000 to 1200° C.Type: ApplicationFiled: June 4, 2007Publication date: December 4, 2008Inventors: Tingkai Li, Douglas J. Tweet, Jer-Shen Maa, Sheng Teng Hsu
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Patent number: 7459375Abstract: A method of fabricating a silicon-on-plastic layer via layer transfer includes depositing a layer of SiGe on a silicon substrate; depositing a layer of silicon; implanting splitting hydrogen ions into the silicon substrate; bonding a glass substrate to the silicon layer; splitting the wafer; removing the silicon layer and a portion of the SiGe layer; depositing a dielectric on the silicon side of the silicon-on-glass wafer; applying adhesive and bonding a plastic substrate to the silicon side of the silicon-on-glass wafer; removing the glass from the glass side of the bonded, silicon-on-glass wafer to form a silicon-on-plastic wafer; and completing a desired IC device on the silicon-on-plastic. Multi-level structure may be fabricated according to the method of the invention by repeating the last few steps of the method of the invention.Type: GrantFiled: August 10, 2007Date of Patent: December 2, 2008Assignee: Sharp Laboratories of America, Inc.Inventors: Jer-Shen Maa, Jong-Jan Lee, Douglas J. Tweet, Sheng Teng Hsu
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Publication number: 20080277701Abstract: An array of fully isolated multi-junction complimentary metal-oxide-semiconductor (CMOS) filterless color imager cells is provided, with a corresponding fabrication process. The color imager cell array is formed from a bulk silicon (Si) substrate without an overlying epitaxial Si layer. A plurality of color imager cells are formed in the bulk Si substrate, where each color imager cell includes a photodiode set and a U-shaped well liner. The photodiode set includes first, second, and third photodiode formed as a stacked multifunction structure, while the U-shaped well liner fully isolates the photodiode set from adjacent photodiode sets in the array. The U-shaped well liner includes a physically interfacing doped well liner bottom and first wall. The well liner bottom is interposed between the substrate and the photodiode set, and the first wall physically interfaces each doped layer of each photodiode in the photodiode set.Type: ApplicationFiled: May 9, 2007Publication date: November 13, 2008Inventors: Jong-Jan Lee, Douglas J. Tweet, Sheng Teng Hsu
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Publication number: 20080280426Abstract: A method is provided for forming a matching thermal expansion interface between silicon (Si) and gallium nitride (GaN) films. The method provides a (111) Si substrate and forms a first aluminum (Al)-containing film in compression overlying the Si substrate. Nano-column holes are formed in the first Al-containing film, which exposes regions of the underlying Si substrate. A layer of GaN layer is selectively grown from the exposed regions, covering the first Al-containing film. The GaN is grown using a lateral nanoheteroepitaxy overgrowth (LNEO) process. The above-mentioned processes are reiterated, forming a second Al-containing film in compression, forming nano-column holes in the second Al-containing film, and selectively growing a second GaN layer. Film materials such as Al2O3, Si1-xGex, InP, GaP, GaAs, AlN, AlGaN, or GaN, may be initially grown at a low temperature. By increasing the growth temperatures, a compressed layer of epitaxial GaN can be formed on a Si substrate.Type: ApplicationFiled: May 9, 2007Publication date: November 13, 2008Inventors: Tingkai Li, Douglas J. Tweet, Jer-Shen Maa, Sheng Teng Hsu
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Patent number: 7442599Abstract: A silicon/germanium (SiGe) superlattice thermal sensor is provided with a corresponding fabrication method. The method forms an active CMOS device in a first Si substrate, and a SiGe superlattice structure on a second Si-on-insulator (SOI) substrate. The first substrate is bonded to the second substrate, forming a bonded substrate. An electrical connection is formed between the SiGe superlattice structure and the CMOS device, and a cavity is formed between the SiGe superlattice structure and the bonded substrate.Type: GrantFiled: September 15, 2006Date of Patent: October 28, 2008Assignee: Sharp Laboratories of America, Inc.Inventors: Jer-Shen Maa, Jinke Tang, Jong-Jan Lee, Douglas J. Tweet, Sheng Teng Hsu
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Patent number: 7419844Abstract: A CMOS active pixel sensor includes a silicon-on-insulator substrate having a silicon substrate with an insulator layer formed thereon and a top silicon layer formed on the insulator layer. A stacked pixel sensor cell includes a bottom photodiode fabricated on the silicon substrate, for sensing light of a longest wavelength; a middle photodiode fabricated on the silicon substrate, for sensing light of a medium wavelength, which is stacked above the bottom photodiode; and a top photodiode fabricated on the top silicon layer, for sensing light of a shorter wavelength, which is stacked above the middle and bottom photodiodes. Pixel transistor sets are fabricated on the top silicon layer and are associated with each pixel sensor cell by electrical connections which extend between each of the photodiodes and respective pixel transistor(s). CMOS control circuitry is fabricated adjacent to an array of active pixel sensor cells and electrically connected thereto.Type: GrantFiled: March 17, 2006Date of Patent: September 2, 2008Assignee: Sharp Laboratories of America, Inc.Inventors: Jong-Jan Lee, Sheng Teng Hsu, Douglas J. Tweet, Jer-Shen Maa
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Patent number: 7413939Abstract: A method of fabricating a silicon-germanium CMOS includes preparing a silicon substrate wafer; depositing an insulating layer on the silicon substrate wafer; patterning and etching the insulating layer; depositing a layer of polycrystalline germanium on the insulating layer and on at least a portion of the silicon substrate wafer; patterning and etching the polycrystalline germanium; encapsulating the polycrystalline germanium with an insulating material; rapidly thermally annealing the wafer at a temperature sufficient to melt the polycrystalline germanium; cooling the wafer to promote liquid phase epitaxy of the polycrystalline germanium, thereby forming a single crystal germanium layer; and completing the CMOS device.Type: GrantFiled: June 10, 2005Date of Patent: August 19, 2008Assignee: Sharp Laboratories of America, Inc.Inventors: Sheng Teng Hsu, Jong-Jan Lee, Jer-Shen Maa, Douglas J. Tweet
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Patent number: 7405098Abstract: A method is provided for forming a liquid phase epitaxial (LPE) germanium (Ge)-on-insulator (GOI) thin-film with a smooth surface. The method provides a silicon (Si) wafer, forms a silicon nitride insulator layer overlying the Si wafer, and selectively etches the silicon nitride insulator layer, forming a Si seed access region. Then, the method conformally deposits Ge overlying the silicon nitride insulator layer and Si seed access region, forming a Ge layer with a first surface roughness, and smoothes the Ge layer using a chemical-mechanical polish (CMP) process. Typically, the method encapsulates the Ge layer and anneals the Ge layer to form a LPE Ge layer. A Ge layer is formed with a second surface roughness, less than the first surface roughness. In some aspects, the method forms an active device in the LPE Ge layer.Type: GrantFiled: January 25, 2006Date of Patent: July 29, 2008Assignee: Sharp Laboratories of America, Inc.Inventors: Jong-Jan Lee, Jer-Shen Maa, Douglas J. Tweet, David R. Evans, Allen Burmaster
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Publication number: 20080173895Abstract: A method is provided for forming a matching thermal expansion interface between silicon (Si) and gallium nitride (GaN) films. The method provides a (111) Si substrate with a first thermal expansion coefficient (TEC), and forms a silicon-germanium (SiGe) film overlying the Si substrate. A buffer layer is deposited overlying the SiGe film. The buffer layer may be aluminum nitride (AlN) or aluminum-gallium nitride (AlGaN). A GaN film is deposited overlying the buffer layer having a second TEC, greater than the first TEC. The SiGe film has a third TEC, with a value in between the first and second TECs. In one aspect, a graded SiGe film may be formed having a Ge content ratio in a range of about 0% to 50%, where the Ge content increases with the graded SiGe film thickness.Type: ApplicationFiled: January 24, 2007Publication date: July 24, 2008Inventors: Jer-Shen Maa, Tingkai Li, Douglas J. Tweet, Gregory M. Stecker, Sheng Teng Hsu
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Publication number: 20080171424Abstract: A method of fabricating a continuous layer of a defect sensitive material on a silicon substrate includes preparing a silicon substrate; forming a nanostructure array directly on the silicon substrate; depositing a selective growth enhancing layer on the substrate; smoothing the selective growth enhancing layer; and growing a continuous layer of the defect sensitive material on the nanostructure array.Type: ApplicationFiled: January 16, 2007Publication date: July 17, 2008Inventors: Tingkai Li, Jer-Shen Maa, Douglas J. Tweet, Wei-Wei Zhuang, Sheng Teng Hsu