Patents by Inventor Chew Hoe Ang

Chew Hoe Ang 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).

  • Patent number: 6610604
    Abstract: A method of forming narrow gates comprising the following steps. A substrate is provided having an overlying Si3N4 or an SiO2/Si3N4 stack gate dielectric layer. A gate material layer is formed over the gate dielectric layer. A hard mask layer is formed over the gate material layer. The hard mask layer and the gate material layer are patterned to form a hard mask/gate material layer stack. A planarized dielectric layer is formed surrounding the hard mask/gate material layer stack. The patterned hard mask layer is removed from over the patterned gate material layer to form a cavity having exposed dielectric layer side walls. Masking spacers are formed on the exposed dielectric layer side walls over a portion of the patterned gate material layer. The patterned gate material layer is etched using the masking spacers as masks to expose a portion of the gate dielectric layer. The planarized dielectric layer is removed. The masking spacers are removed to form narrow gates comprising gate material.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: August 26, 2003
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chew-Hoe Ang, Eng-Hua Lim, Randall Cha, Jia-Zhen Zheng, Elgin Quek, Mei-Sheng Zhou, Daniel Yen
  • Publication number: 20030152871
    Abstract: A method of forming small features, comprising the following steps. A substrate having a dielectric layer formed thereover is provided. A spacing layer is formed over the dielectric layer. The spacing layer has a thickness equal to the thickness of the small feature to be formed. A patterned, re-flowable masking layer is formed over the spacing layer. The masking layer having a first opening with a width “L”. The patterned, re-flowable masking layer is re-flowed to form a patterned, re-flowed masking layer having a re-flowed first opening with a lower width “1”. The re-flowed first opening lower width “1” being less than the pre-reflowed first opening width “L”. The spacing layer is etched down to the dielectric layer using the patterned, re-flowed masking layer as a mask to form a second opening within the etched spacing layer having a width equal to the re-flowed first opening lower width “1”. Removing the patterned, re-flowed masking layer.
    Type: Application
    Filed: February 8, 2002
    Publication date: August 14, 2003
    Applicant: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chew-Hoe Ang, Eng Hua Lim, Randall Cha, Jia-Zhen Zheng, Elgin Quek, Mei-Sheng Zhou, Daniel Yen
  • Publication number: 20030153139
    Abstract: 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: Application
    Filed: February 8, 2002
    Publication date: August 14, 2003
    Applicant: 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
  • Patent number: 6605501
    Abstract: 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: Grant
    Filed: June 6, 2002
    Date of Patent: August 12, 2003
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chew-Hoe Ang, Eng-Hua Lim, Cher-Liang Cha, Jia-Zhen Zheng, Elgin Quek, Mei-Sheng Zhou
  • Publication number: 20030148617
    Abstract: A method of forming narrow gates comprising the following steps. A substrate is provided having an overlying Si3N4 or an SiO2/Si3N4 stack gate dielectric layer. A gate material layer is formed over the gate dielectric layer. A hard mask layer is formed over the gate material layer. The hard mask layer and the gate material layer are patterned to form a hard mask/gate material layer stack. A planarized dielectric layer is formed surrounding the hard mask/gate material layer stack. The patterned hard mask layer is removed from over the patterned gate material layer to form a cavity having exposed dielectric layer side walls. Masking spacers are formed on the exposed dielectric layer side walls over a portion of the patterned gate material layer. The patterned gate material layer is etched using the masking spacers as masks to expose a portion of the gate dielectric layer. The planarized dielectric layer is removed. The masking spacers are removed to form narrow gates comprising gate material.
    Type: Application
    Filed: February 5, 2002
    Publication date: August 7, 2003
    Applicant: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chew-Hoe Ang, Eng-Hua Lim, Randall Cha, Jia-Zhen Zheng, Elgin Quek, Mei-Sheng Zhou, Daniel Yen
  • Patent number: 6586314
    Abstract: A method of forming a shallow trench isolation (STI), region in a semiconductor substrate featuring a process sequence that results in desired rounded corners for the sides of active device regions located butting the STI region, has been developed. The process sequence features formation of, followed by removal of, a silicon dioxide layer which was thermally grown in a top portion of the semiconductor substrate, wherein the top portion of semiconductor was subjected to an ion implantation procedure prior to the oxidation procedure. The above process sequence results in a recessed portion of semiconductor located adjacent to unoxidized portions of semiconductor which underlay an oxidation resistant shape, and feature rounded corners. Insulator spacers are then formed on the sides of the oxidation resistant shape, overlying and protecting the rounded comers of subsequent active device regions from a dry etch procedure used to selectively define a shallow trench shape in the exposed semiconductor region.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: July 1, 2003
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Soh Yun Siah, Liang Choo Hsia, Jia Zhen Zheng, Chew Hoe Ang
  • Patent number: 6544848
    Abstract: A new method of forming a sharp tip on a floating gate in the fabrication of a EEPROM memory cell is described. A first gate dielectric layer is provided on a substrate. A second gate dielectric layer is deposited overlying the first gate dielectric layer. A floating gate/control gate stack is formed overlying the second gate dielectric layer. One sidewall portion of the floating gate is covered with a mask. The second gate dielectric layer not covered by the mask is etched away whereby an undercut of the floating gate is formed in the second gate dielectric layer. The mask is removed. Polysilicon spacers are formed on sidewalls of the floating gate wherein one of the polysilicon spacers fills the undercut thereby forming a sharp polysilicon tip to improve the erase efficiency of the memory cell.
    Type: Grant
    Filed: August 20, 2002
    Date of Patent: April 8, 2003
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chew Hoe Ang, Eng Hua Lim, Randall Cha, Jia Zhen Zheng, Elgin Quek, Mei Sheng Zhou, Daniel Yen
  • Patent number: 6468851
    Abstract: 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: Grant
    Filed: January 2, 2002
    Date of Patent: October 22, 2002
    Assignee: 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
  • Patent number: 6429109
    Abstract: A method of forming a gate comprising the following steps. A substrate is provided. A pre-gate structure is formed over the substrate. The pregate structure includes a sacrificial metal layer between an upper gate conductor layer and a lower gate dielectric layer. The pre-gate structure is annealed to form the gate. The gate comprising: an upper silicide layer formed from a portion of the sacrificial metal layer and a portion of the upper gate conductor layer from the anneal; and a lower metal oxide layer formed from a portion of the gate dielectric layer and a portion of the sacrificial metal layer from the anneal.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: August 6, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd
    Inventors: Jia Zhen Zheng, Elgin Quek, Mei Sheng Zhou, Daniel Yen, Chew Hoe Ang, Eng Hua Lim, Randall Cha
  • Patent number: 6403425
    Abstract: A new method is provided for the creation of layers of gate oxide of different thicknesses. A substrate is provided, the surface of the substrate is divided into a first surface region over which a thick layer of gate oxide has to be created and a second surface region over which a thin layer of gate oxide is to be created. Thick gate-oxide implants are performed into the surface of the substrate. A thick layer of gate oxide is created over the surface of the substrate, the thick layer of gate oxide is successively patterned for thin gate-oxide implants, comprising thin gate-oxide n-well/p-well, threshold, punchthrough implants, into the second surface region of the substrate. The thick layer of gate oxide is removed from the second surface region of the substrate. The (now contaminated) top layer of the thick layer of gate oxide is removed, a thin layer of gate oxide is grown over the second surface region of the substrate.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: June 11, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chew-Hoe Ang, Wenhe Lin, Jia Zhen Zheng