Patents by Inventor Cher Liang Cha
Cher Liang Cha 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: 6727151Abstract: A method for forming a MOSFET having an elevated source/drain structure is described. A sacrificial oxide layer is provided on a substrate. A polish stop layer is deposited overlying the sacrificial oxide layer. An oxide layer is deposited overlying the polish stop layer. An opening is formed through the oxide layer and the polish stop layer to the sacrificial oxide layer. First polysilicon spacers are formed on sidewalls of the opening wherein the first polysilicon spacers form an elevated source/drain structure. Second polysilicon spacers are formed on the first polysilicon spacers. The oxide layer and sacrificial oxide layer exposed within the opening are removed. An epitaxial silicon layer is grown within the opening. A gate dielectric layer is formed within the opening overlying the second polysilicon spacers and the epitaxial silicon layer. A gate material layer is deposited within the opening.Type: GrantFiled: August 7, 2002Date of Patent: April 27, 2004Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Yung Fu Chong, Randall Cher Liang Cha, Alex See
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Publication number: 20040033668Abstract: A method for forming a transistor having an elevated source/drain structure is described. A gate electrode is formed overlying a substrate and isolated from the substrate by a gate dielectric layer. Isolation regions are formed in and on the substrate wherein the isolation regions have a stepped profile wherein an upper portion of the isolation regions partly overlaps and is offset from a lower portion of the isolation regions in the direction away from the gate electrode. Ions are implanted into the substrate between the gate electrode and the isolation regions to form source/drain extensions. Dielectric spacers are formed on sidewalls of the gate electrode and the isolation regions.Type: ApplicationFiled: August 16, 2002Publication date: February 19, 2004Applicant: Chartered Semiconductor Manufacturing Ltd.Inventors: Randall Cher Liang Cha, Yeow Kheng Lim, Alex Kai Hung See, Jia Zhen Zheng
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Patent number: 6680239Abstract: A method for forming shallow trench isolation (STI) with a higher aspect ratio is given. This method allows the formation of narrower and deeper trench isolation regions while avoiding substrate damage due to excessive etching and severe microloading effects. In addition, it yields uniform depth trenches while avoiding problems of etch residue at the bottom of the trench. This method is achieved by using a process where a trench is etched, and an oxide layer grown along the bottom and sidewalls of the trench. Oxygen or field isolation ions are then implanted into the bottom of the trench. A nitride spacer is then formed along the bottom and sidewalls of the trench, followed by an isotropic etch removing the nitride and oxide from the bottom of the trench. An oxide deposition then fills the trench, followed by a planarization step completing the isolation structure.Type: GrantFiled: July 24, 2000Date of Patent: January 20, 2004Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Cher Liang Cha, Kok Keng Ong, Alex See, Lap Chan
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Patent number: 6664153Abstract: A method for forming a single gate having a dual work-function is described. A gate electrode is formed overlying a gate dielectric layer on a substrate. Sidewalls of the gate electrode are selectively doped whereby the doped sidewalls have a first work-function and whereby a central portion of the gate electrode not doped has a second work-function to complete formation of a single gate having multiple work-functions in the fabrication of integrated circuits.Type: GrantFiled: February 8, 2002Date of Patent: December 16, 2003Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Chew Hoe Ang, Eng Hua Lim, Randall Cher Liang Cha, Jia Zhen Zheng, Elgin Quek, Mei Sheng Zhou, Daniel Yen
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Publication number: 20030207565Abstract: A method for forming a thicker silicide over a MOS device is described. This is achieved using a process where the gate structure is formed by conventional techniques upon a substrate. A low-energy implantation is performed to form lightly doped source and drain (LDD) regions in the substrate in the areas not protected by the gate structure. A first spacer composed of tetraethyl-oxysilane (TEOS oxide), for example, is formed along the sidewalls of the gate structure. A second low-energy implantation is performed to form the source and drain (S/D) in the areas not protected by the gate structure and first spacer. A layer of metal such as titanium (Ti), for example, is then deposited over the surface of the gate structure. A second sidewall spacer composed of titanium nitride (TiN), for example, is formed along the sidewalls of the gate structure covering the metal over the first sidewall spacer and covering the metal over isolation regions.Type: ApplicationFiled: June 9, 2003Publication date: November 6, 2003Inventors: Cheng Cheh Tan, Randall Cher Liang Cha, Alex See, Lap Chan
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Publication number: 20030197279Abstract: An integrated circuit and manufacturing method therefor is provided having a base with a first dielectric layer formed thereon. A second dielectric layer is formed over the first dielectric layer. A third dielectric layer is formed in spaced-apart strips over the second dielectric layer. A first trench opening is formed through the first and second dielectric layers between the spaced-apart strips of the third dielectric layer. A second trench opening is formed contiguously with the first trench opening through the first dielectric layer between the spaced-apart strips of the third dielectric layer. Conductor metals in the trench openings form self-aligned trench interconnects.Type: ApplicationFiled: April 23, 2002Publication date: October 23, 2003Applicant: Chartered Semiconductor Manufacturing Ltd.Inventors: Yeow Kheng Lim, Randall Cher Liang Cha, Alex See, Wang Ling Goh
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Patent number: 6613652Abstract: A method to form SOI devices using wafer bonding. A first substrate is provided having trenches in a first side. A first insulating layer is formed over the first side of the first substrate and filling the trenches. We planarize the first insulating layer to form isolation regions (e.g., STI). The three embodiments of the invention planarize the first insulating layer to different levels. In the second embodiment, the first insulating layer is etched back to form a recess. This recess later forms an air gap. We provide a second substrate having a second insulating layer over a first side of the second substrate. We bond the second insulating layer to the first insulating layer. Next, we thin the first substrate from the second side to expose the first insulating layer to form active areas between the isolation regions. Lastly, devices are formed in and on the active areas.Type: GrantFiled: March 14, 2001Date of Patent: September 2, 2003Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Yeow Kheng Lim, Randall Cher Liang Cha, Alex See, Tae Jong Lee, Wang Ling Goh
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Patent number: 6610575Abstract: A method of structures having dual gate oxide thicknesses, comprising the following steps. A substrate having first and second pillars is provided. The first and second pillars each having an outer side wall and an inner side wall. At least one of the outer or inner side walls of at least one of the first and second pillars is/are masked leaving at least one of the outer or inner side walls of at least one of the first and second pillars exposed. Dopants are then implanted through the at least one of the exposed outer or inner side walls modifying the surface of the at least one of the doped exposed outer or inner side walls. The at least one of the masked outer or inner side walls of at least one of the first and second pillars is/are unmasked.Type: GrantFiled: June 4, 2002Date of Patent: August 26, 2003Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Chew-Hoe Ang, Eng-Hua Lim, Cher-Liang Cha, Jia-Zhen Zheng, Elgin Quek, Mei-Sheng Zhou, Daniel Yen
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Publication number: 20030153139Abstract: A method for forming a single gate having a dual work-function is described. A gate electrode is formed overlying a gate dielectric layer on a substrate. Sidewalls of the gate electrode are selectively doped whereby the doped sidewalls have a first work-function and whereby a central portion of the gate electrode not doped has a second work-function to complete formation of a single gate having multiple work-functions in the fabrication of integrated circuits.Type: ApplicationFiled: February 8, 2002Publication date: August 14, 2003Applicant: Chartered Semiconductor Manufacturing Ltd.Inventors: Chew Hoe Ang, Eng Hua Lim, Randall Cher Liang Cha, Jia Zhen Zheng, Elgin Quek, Mei Sheng Zhou, Daniel Yen
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Patent number: 6605501Abstract: A method of fabricating dual gate oxide thicknesses comprising the following steps. A substrate is provided having a first pillar and a second pillar. A gate dielectric layer is formed over the substrate and the first and second pillars. First and second thin spacers are formed over the gate dielectric layer covered side walls of the first and second pillars respectively. The second pillar is masked leaving the first pillar unmasked. The first thin spacers are removed from the unmasked first pillar. The mask is removed from the masked second pillar. The structure is oxidized to convert the second thin spacers to second preliminary gate oxide over the previously masked second pillar and to form first preliminary gate oxide over the unmasked first pillar. The second gate oxide over the second pillar being thicker than the first gate oxide over the first pillar.Type: GrantFiled: June 6, 2002Date of Patent: August 12, 2003Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Chew-Hoe Ang, Eng-Hua Lim, Cher-Liang Cha, Jia-Zhen Zheng, Elgin Quek, Mei-Sheng Zhou
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Publication number: 20030107083Abstract: A silicon-on-insulator semiconductor device is provided in which a single wafer die contains a transistor over an insulator layer to form a fully depleted silicon-on-insulator device and a transistor formed in a semiconductor island over an insulator structure on the semiconductor wafer forms a partially depleted silicon-on-insulator device.Type: ApplicationFiled: December 19, 2002Publication date: June 12, 2003Inventors: Randall Cher Liang Cha, Yeow Kheng Lim, Alex See, Tae Jong Lee, Wang Ling Goh
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Patent number: 6566209Abstract: A method of forming shallow junction MOSFETs is achieved. A gate oxide layer is formed overlying a substrate. A first electrode layer, of polysilicon or metal, is deposited. A silicon nitride layer is deposited. The silicon nitride layer and the first electrode layer are etched through to form temporary MOSFET gates. Ions are implanted into the substrate to form lightly doped junctions. A spacer layer is deposited. The spacer layer and the gate oxide layer are anisotropically etched to form sidewall spacers. Ions are implanted into the substrate to form heavily doped junctions. The silicon nitride layer is etched away. A second electrode layer, of polysilicon or metal, is deposited overlying the substrate, the sidewall spacers, and the first polysilicon layer. The second electrode layer is polished down to the top surfaces of the sidewall spacers to complete the MOSFETs and to form permanent gates and conductive connections to the source and drain junctions.Type: GrantFiled: August 31, 2001Date of Patent: May 20, 2003Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Lap Chan, Cher Liang Cha, Ravishankar Sundaresan
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Patent number: 6558994Abstract: A silicon-on-insulator semiconductor device and manufacturing method therefor is provided in which a single wafer die contains a transistor over an insulator layer to form a fully depleted silicon-on-insulator device and a transistor formed in a semiconductor island over an insulator structure on the semiconductor wafer forms a partially depleted silicon-on-insulator device.Type: GrantFiled: March 1, 2001Date of Patent: May 6, 2003Assignee: Chartered Semiconductors Maufacturing Ltd.Inventors: Randall Cher Liang Cha, Yeow Kheng Lim, Alex See, Tae Jong Lee, Wang Ling Goh
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Patent number: 6531750Abstract: A method of forming shallow junction MOSFETs is achieved. A gate oxide layer is formed overlying a substrate. A first electrode layer, of polysilicon or metal, is deposited. A silicon nitride layer is deposited. The silicon nitride layer and the first electrode layer are etched through to form temporary MOSFET gates. Ions are implanted into the substrate to form lightly doped junctions. A spacer layer is deposited. The spacer layer and the gate oxide layer are anisotropically etched to form sidewall spacers. Ions are implanted into the substrate to form heavily doped junctions. The silicon nitride layer is etched away. A second electrode layer, of polysilicon or metal, is deposited overlying the substrate, the sidewall spacers, and the first polysilicon layer. The second electrode layer is polished down to the top surfaces of the sidewall spacers to complete the MOSFETs and to form permanent gates and conductive connections to the source and drain junctions.Type: GrantFiled: August 31, 2001Date of Patent: March 11, 2003Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Lap Chan, Cher Liang Cha, Ravishankar Sundaresan
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Patent number: 6501122Abstract: A new method of fabricating a stacked gate Flash EEPROM device having an improved interpoly oxide layer is described. A gate oxide layer is provided on the surface of a substrate. A first polysilicon layer is deposited overlying the gate oxide layer and patterned to form a floating gate. Source and drain regions associated with the floating gate are formed within the substrate. An oxide layer is deposited overlying the floating gate and the substrate. The oxide layer is polished away until the top of the oxide layer is even with the top of the floating gate. A second polysilicon layer is deposited overlying the oxide layer and the first polysilicon layer of the floating gate wherein the second polysilicon layer has a smooth surface. An interpoly dielectric layer is deposited overlying the second polysilicon layer. A third polysilicon layer is deposited overlying the interpoly dielectric layer.Type: GrantFiled: March 24, 2000Date of Patent: December 31, 2002Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Lap Chan, Cher Liang Cha
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Patent number: 6483148Abstract: A method of forming a self-aligned elevated transistor using selective epitaxial growth is described. An oxide layer is provided overlying a semiconductor substrate. The oxide layer is etched through to the semiconductor substrate to form a trench having a lower portion contacting the substrate and an upper portion having a width larger than the width of the lower portion. A silicon layer is grown within the trench using selective epitaxial growth wherein the silicon layer fills the lower portion and partially fills the upper portion. Nitride spacers are formed on the sidewalls of the trench. A polysilicon layer is deposited overlying the oxide layer and within the trench and etched back to form a gate electrode within the trench between the nitride spacers. The nitride spacers are etched away where they are not covered by the gate electrode leaving thin nitride spacers on sidewalls of the gate electrode.Type: GrantFiled: February 1, 2002Date of Patent: November 19, 2002Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Lap Chan, Cher Liang Cha
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Patent number: 6472697Abstract: A method of manufacturing conductive lines that are thicker (not wider) in the critical paths areas. We form a plurality of first level conductive lines over a first dielectric layer. The first conductive lines run in a first direction. The first level conductive lines are comprised of a first level first conductive line and a second first level conductive line. We form a second dielectric layer over the first level conductive lines and the first dielectric layer. Next, we form a via opening in the second dielectric layer over a portion of the first level first conductive line. A plug is formed filling the via opening. We form a trench pattern in the second dielectric layer. The trench pattern is comprised of trenches that are approximately orthogonal to the first level conductive lines. We fill the trenches with a conductive material to form supplemental second lines. We form second level conductive lines over the supplemental second lines and the plug.Type: GrantFiled: May 8, 2002Date of Patent: October 29, 2002Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Yeow Kheng Lim, Randall Cher Liang Cha, Alex See, Wang Ling Goh, Victor Seng Keong Lim
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Patent number: 6468880Abstract: A method to form a silicon on insulator (SOI) device using wafer bonding. A first substrate is provided having an insulating layer over a first side. A second substrate is provided having first isolation regions (e.g., STI) that fill first trenches in the second substrate. Next, we bond the first and second substrate together by bonding the insulating layer to the first isolation regions and the second substrate. Then, a stop layer is formed over the second side of the second substrate. The stop layer and the second side of the second substrate are patterned to form second trenches in the second substrate. The second trenches have sidewalls at least partially defined by the isolation regions and the second trenches expose the second insulating layer. The second trenches define first active regions over the first isolation regions (STI) and define second active regions over the insulating layer. Next, the second trenches are filled with an insulator material to from second isolation regions.Type: GrantFiled: March 15, 2001Date of Patent: October 22, 2002Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Yeow Kheng Lim, Randall Cher Liang Cha, Alex See, Tae Jong Lee, Wang Ling Goh
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Patent number: 6468851Abstract: A method of fabricating a dual gate electrode CMOS device having dual gate electrodes. An N+ poly gate is used for the nMOSFET and a metal gate is used for the pMOSFET. The N+ nMOSFET poly gate may be capped with a highly conductive metal to reduce its gate resistance. A sacrificial cap is used for the N+ poly gate to eliminate a mask level for the dual gate electrodes.Type: GrantFiled: January 2, 2002Date of Patent: October 22, 2002Assignee: Chartered Semiconductor Manufacturing Ltd.Inventors: Chew-Hoe Ang, Eng-Hua Lim, Randall Cher Liang Cha, Jia-Zhen Zheng, Elgin Kiok Boone Quek, Mei-Sheng Zhou, Daniel Lee-Wei Yen
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Publication number: 20020127834Abstract: A method of manufacturing conductive lines that are thicker (not wider) in the critical paths areas. We form a plurality of first level conductive lines over a first dielectric layer. The first conductive lines run in a first direction. The first level conductive lines are comprised of a first level first conductive line and a second first level conductive line. We form a second dielectric layer over the first level conductive lines and the first dielectric layer. Next, we form a via opening in the second dielectric layer over a portion of the first level first conductive line. A plug is formed filling the via opening. We form a trench pattern in the second dielectric layer. The trench pattern is comprised of trenches that are approximately orthogonal to the first level conductive lines. We fill the trenches with a conductive material to form supplemental second lines. We form second level conductive lines over the supplemental second lines and the plug.Type: ApplicationFiled: May 8, 2002Publication date: September 12, 2002Applicant: CHARTERED SEMICONDUCTOR MANUFACTURING LTD.Inventors: Yeow Kheng Lim, Randall Cher Liang Cha, Alex See, Wang Ling Goh, Victor Seng Keong Lim