Patents by Inventor Tsu-Jae Liu
Tsu-Jae Liu 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: 10347501Abstract: Methods for achieving sub-lithographic feature sizes in an integrated circuit (IC) layer are provided that use ion implantation to enhance or reduce the etch rate of a thin masking layer. The etch rates also can be enhanced or reduced at specific locations through multiple implantation steps. The implantation can be performed at tilted angles to achieve sub-lithographic implanted regions that are self-aligned to pre-existing photoresist or hard-mask features over the masking layer on the surface of a substrate. A higher density of features can be achieved in an IC layer than are present in an overlying masking layer with the use of ion implantation.Type: GrantFiled: October 31, 2017Date of Patent: July 9, 2019Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Tsu-Jae Liu, Xi Zhang, Peng Zheng
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Publication number: 20180130668Abstract: Methods for achieving sub-lithographic feature sizes in an integrated circuit (IC) layer are provided that use ion implantation to enhance or reduce the etch rate of a thin masking layer. The etch rates also can be enhanced or reduced at specific locations through multiple implantation steps. The implantation can be performed at tilted angles to achieve sub-lithographic implanted regions that are self-aligned to pre-existing photoresist or hard-mask features over the masking layer on the surface of a substrate. A higher density of features can be achieved in an IC layer than are present in an overlying masking layer with the use of ion implantation.Type: ApplicationFiled: October 31, 2017Publication date: May 10, 2018Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Tsu-Jae Liu, Xi Zhang, Peng Zheng
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Publication number: 20070128782Abstract: By forming MOSFETs on a substrate having pre-existing ridges of semiconductor material (i.e., a “corrugated substrate”), the resolution limitations associated with conventional semiconductor manufacturing processes can be overcome, and high-performance, low-power transistors can be reliably and repeatably produced. Forming a corrugated substrate prior to actual device formation allows the ridges on the corrugated substrate to be created using high precision techniques that are not ordinarily suitable for device production. MOSFETs that subsequently incorporate the high-precision ridges into their channel regions will typically exhibit much more precise and less variable performance than similar MOSFETs formed using optical lithography-based techniques that cannot provide the same degree of patterning accuracy. Additional performance enhancement techniques such as pulse-shaped doping, “wrapped” gates, epitaxially grown conductive regions, epitaxially grown high mobility semiconductor materials (e.g.Type: ApplicationFiled: January 30, 2007Publication date: June 7, 2007Applicant: Synopsys, Inc.Inventors: Tsu-Jae Liu, Qiang Lu
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Publication number: 20070122953Abstract: By forming MOSFETs on a substrate having pre-existing ridges of semiconductor material (i.e., a “corrugated substrate”), the resolution limitations associated with conventional semiconductor manufacturing processes can be overcome, and high-performance, low-power transistors can be reliably and repeatably produced. Forming a corrugated substrate prior to actual device formation allows the ridges on the corrugated substrate to be created using high precision techniques that are not ordinarily suitable for device production. MOSFETs that subsequently incorporate the high-precision ridges into their channel regions will typically exhibit much more precise and less variable performance than similar MOSFETs formed using optical lithography-based techniques that cannot provide the same degree of patterning accuracy. Additional performance enhancement techniques such as pulse-shaped doping, “wrapped” gates, epitaxially grown conductive regions, epitaxially grown high mobility semiconductor materials (e.g.Type: ApplicationFiled: January 30, 2007Publication date: May 31, 2007Applicant: Synopsys, Inc.Inventors: Tsu-Jae Liu, Qiang Lu
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Publication number: 20070122954Abstract: By forming MOSFETs on a substrate having pre-existing ridges of semiconductor material (i.e., a “corrugated substrate”), the resolution limitations associated with conventional semiconductor manufacturing processes can be overcome, and high-performance, low-power transistors can be reliably and repeatably produced. Forming a corrugated substrate prior to actual device formation allows the ridges on the corrugated substrate to be created using high precision techniques that are not ordinarily suitable for device production. MOSFETs that subsequently incorporate the high-precision ridges into their channel regions will typically exhibit much more precise and less variable performance than similar MOSFETs formed using optical lithography-based techniques that cannot provide the same degree of patterning accuracy. A multi step epitaxial process can be used to extend the ridges with different dopant types, high mobility semiconductor, and or advanced multi-layer strutures.Type: ApplicationFiled: January 30, 2007Publication date: May 31, 2007Applicant: Synopsys, Inc.Inventors: Tsu-Jae Liu, Qiang Lu
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Publication number: 20070120186Abstract: A negative differential resistance (NDR) transistor includes a gate stack formed from a gate, a barrier layer, and a dielectric layer formed between the gate and barrier layer. To enable the NDR characteristic of the transistor, the barrier layer is configured to dynamically transfer charge carriers to and from the channel region of the transistor (e.g., to a charge storage node between the barrier layer and the dielectric layer), thereby adjusting the threshold voltage of the transistor. An NDR transistor can also be formed with a gap between the edge of the source region and the edge of the gate (stack) to enhance the electric field in the portion of the channel region corresponding to the gap. The enhanced electric field can concentrate the distribution of charge carriers removed from the channel region in the proximity of the source region, thereby enhancing the NDR performance of the transistor.Type: ApplicationFiled: November 29, 2005Publication date: May 31, 2007Applicant: Synopsys, Inc.Inventors: Qiang Lu, Tsu-Jae Liu
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Publication number: 20070120156Abstract: By forming MOSFETs on a substrate having pre-existing ridges of semiconductor material (i.e., a “corrugated substrate”), the resolution limitations associated with conventional semiconductor manufacturing processes can be overcome, and high-performance, low-power transistors can be reliably and repeatably produced. Forming a corrugated substrate prior to actual device formation allows the ridges on the corrugated substrate to be created using high precision techniques that are not ordinarily suitable for device production. MOSFETs that subsequently incorporate the high-precision ridges into their channel regions will typically exhibit much more precise and less variable performance than similar MOSFETs formed using optical lithography-based techniques that cannot provide the same degree of patterning accuracy. Additional performance enhancement techniques such as pulse-shaped doping, “wrapped” gates, epitaxially grown conductive regions, epitaxially grown high mobility semiconductor materials (e.g.Type: ApplicationFiled: January 30, 2007Publication date: May 31, 2007Applicant: Synopsys, Inc.Inventors: Tsu-Jae Liu, Qiang Lu
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Publication number: 20060125017Abstract: A memory cell includes two negative differential resistance (NDR) field effect transistors (FETs) forming a bistable latch, and an access transistor for allowing data to be passed to and from the storage node formed by the bistable latch. By stacking the NDR-FETs and the access transistor in two or more layers, area requirements for the memory cell can be reduced, thereby enabling increased circuit density in an integrated circuit (IC) incorporating the memory cell.Type: ApplicationFiled: January 31, 2006Publication date: June 15, 2006Applicant: Synopsys, Inc.Inventor: Tsu-Jae Liu