Patents by Inventor Lap Chan

Lap Chan 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: 6387747
    Abstract: A method for forming an RF inductor of helical shape having high Q and minimum area. The inductor is fabricated of metal or damascened linear segments formed on three levels of intermetal dielectric layers and interconnected by metal filled vias to form the complete helical shape with electrical continuity.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: May 14, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Randall Cha, Tae Jong Lee, Alex See, Lap Chan, Chua Chee Tee
  • Patent number: 6384437
    Abstract: Low current leakage DRAM structures are achieved using a selective silicon epitaxial growth over an insulating layer on memory cell (device) areas. An insulating layer, that also serves as a stress-release layer, and a Si3N4 hard mask are patterned to leave portions over the memory cell areas. Shallow trenches are etched in the substrate and filled with a CVD oxide which is polished back to the hard mask to form shallow trench isolation (STI) around the memory cell areas. The hard mask is selectively removed to form recesses in the STI aligned over the memory cell areas exposing the underlying insulating layer. Openings are etched in the insulating layer to provide a silicon-seed surface from which is grown a selective epitaxial layer extending over the insulating layer within the recesses. After growing a gate oxide on the epitaxial layer, FETs and DRAM capacitors can be formed on the epitaxial layer.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: May 7, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Kheng Chok Tee, Randall Cher Liang Cha, Lap Chan
  • Publication number: 20020052077
    Abstract: Low current leakage DRAM structures are achieved using a selective silicon epitaxial growth over an insulating layer on memory cell (device) areas. An insulating layer, that also serves as a stress-release layer, and a Si3N4 hard mask are patterned to leave portions over the memory cell areas. Shallow trenches are etched in the substrate and filled with a CVD oxide which is polished back to the hard mask to form shallow trench isolation (STI) around the memory cell areas. The hard mask is selectively removed to form recesses in the STI aligned over the memory cell areas exposing the underlying insulating layer. Openings are etched in the insulating layer to provide a silicon-seed surface from which is grown a selective epitaxial layer extending over the insulating layer within the recesses. After growing a gate oxide on the epitaxial layer, FETs and DRAM capacitors can be formed on the epitaxial layer.
    Type: Application
    Filed: September 27, 2001
    Publication date: May 2, 2002
    Applicant: CHARTERED SEMICONDUCTOR MANUFACTURING LTD.
    Inventors: Kheng Chok Tee, Randall Cher Liang Cha, Lap Chan
  • Patent number: 6380088
    Abstract: An improved MOS transistor and method of making an improved MOS transistor. An MOS transistor having a recessed source drain on a trench sidewall with a replacement gate technique. Holes are formed in the shallow trench isolations, which exposes sidewall of the substrate in the active area. Sidewalls of the substrate are doped in the active area where holes are. Conductive material is then formed in the holes and the conductive material becomes the source and drain regions. The etch stop layer is then removed exposing sidewalls of the conductive material, and oxidizing exposed sidewalls of the conductive material is preformed. Spacers are formed on top of the pad oxide and on the sidewalls of the oxidized portions of the conductive material. The pad oxide layer is removed from the structure but not from under the spacers. A gate dielectric layer is formed on the substrate in the active area between the spacers; and a gate electrode is formed on said gate dielectric layer.
    Type: Grant
    Filed: January 19, 2001
    Date of Patent: April 30, 2002
    Assignee: Chartered Semiconductor Manufacturing, Inc.
    Inventors: Lap Chan, Elgin Quek, Ravi Sundaresan, Yang Pan, James Yong Meng Lee, Ying Keung Leung, Yelehanka Ramachandramurthy Pradeep, Jia Zhen Zheng
  • Patent number: 6355563
    Abstract: A method to integrate low dielectric constant dielectric materials with copper metallization is described. A metal line is provided overlying a semiconductor substrate and having a nitride capping layer thereover. A polysilicon layer is deposited over the nitride layer and patterned to form dummy vias. A dielectric liner layer is conformally deposited overlying the nitride layer and dummy vias. A dielectric layer having a low dielectric constant is spun-on overlying the liner layer and covering the dummy vias. The dielectric layer is polished down whereby the dummy vias are exposed. Thereafter, the dielectric layer is cured whereby a cross-linked surface layer is formed. The dummy vias are removed thereby exposing a portion of the nitride layer within the via openings. The exposed nitride layer is removed. The via openings are filled with a copper layer which is planarized to complete copper metallization in the fabrication of an integrated circuit device.
    Type: Grant
    Filed: March 5, 2001
    Date of Patent: March 12, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Randall Cher Liang Cha, Alex See, Yeow Kheng Lim, Tae Jong Lee, Lap Chan
  • Patent number: 6348385
    Abstract: The method for a transistor using a replacement gate process that has a doped low-K dielectric spacer that lowers the junction capacitance. A dummy gate is formed over a substrate. Ions are implanted into the substrate using the dummy gate as an implant mask to form source and drain regions. A masking layer is formed on the substrate over the source and drain regions. We remove the dummy gate. Doped low k spacers are formed on the sidewalls of the masking layer. The doped spacers are heated to diffuse dopant into the substrate to form lightly doped drain (LDD regions). We form a high k gate dielectric layer over the masking layer. A gate layer is formed over the high K dielectric layer. The gate layer is chemical-mechanical polished (CMP) to form a gate over the high k dielectric layer and to remove the gate layer over the masking layer.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: February 19, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Randall Cher Liang Cha, Tae Jong Lee, Alex See, Lap Chan, Chee Tee Chua
  • Publication number: 20020011629
    Abstract: 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: Application
    Filed: August 31, 2001
    Publication date: January 31, 2002
    Applicant: CHARTERED SEMICONDUCTOR MANUFACTURING LTD.
    Inventors: Lap Chan, Cher Liang Cha, Ravishankar Sundaresan
  • Publication number: 20020003264
    Abstract: 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: Application
    Filed: August 31, 2001
    Publication date: January 10, 2002
    Applicant: CHARTERED SEMICONDUCTOR MANUFACTURING LTD.
    Inventors: Lap Chan, Cher Liang Cha, Ravishankar Sundaresan
  • Patent number: 6326272
    Abstract: 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: Grant
    Filed: November 18, 1999
    Date of Patent: December 4, 2001
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Lap Chan, Cher Liang Cha
  • Patent number: 6323125
    Abstract: Only one photo mask defines the metal trench and via region. The mask blocks the UV light in the trench and via area forming Plasma Polymerized Methylsilane Oxide (PPMSO) in the exposed areas. Two step RIE plasma treatment using chlorine gas and oxygen gas removes the Plasma Polymerized Methylsilane (PPMS) in the trench and via regions. Conductive metal is deposited. A CMP process polishes back both excess metal along with the PPMSO, at a similar rate, to form: conducting metal lines, interconnects, and via contacts without metal dishing.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: November 27, 2001
    Assignees: Chartered Semiconductor Manufacturing Ltd, National University of Singapore, Nahyang Technological University of Singapore
    Inventors: Choi Pheng Soo, Wye Boon Loh, Lap Chan
  • Patent number: 6319767
    Abstract: A method for fabricating a metal-insulator-metal capacitor wherein top metal corner shaping during patterning is eliminated is described. An insulating layer is provided overlying a semiconductor substrate. A composite metal stack is formed comprising a first metal layer overlying the insulating layer, a capacitor dielectric layer overlying the first metal layer, a second metal layer overlying the capacitor dielectric layer, and a hard mask layer overlying the second metal layer. A first photoresist mask is formed overlying the hard mask layer. The composite metal stack is patterned using the first photoresist mask as an etching mask whereby the patterned first metal layer forms a bottom electrode of the capacitor. A portion of the first photoresist mask is removed by plasma ashing to form a second photoresist mask narrower than the first photoresist mask. The hard mask layer is patterned using the second photoresist mask as an etching mask.
    Type: Grant
    Filed: March 5, 2001
    Date of Patent: November 20, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Randall Cher Liang Cha, Tae Jong Lee, Alex See, Lap Chan, Yeow Kheng Lim
  • Patent number: 6319772
    Abstract: Low current leakage DRAM structures are achieved using a selective silicon epitaxial growth over an insulating layer on memory cell (device) areas. An insulating layer, that also serves as a stress-release layer, and a Si3N4 hard mask are patterned to leave portions over the memory cell areas. Shallow trenches are etched in the substrate and filled with a CVD oxide which is polished back to the hard mask to form shallow trench isolation (STI) around the memory cell areas. The hard mask is selectively removed to form recesses in the STI aligned over the memory cell areas exposing the underlying insulating layer. Openings are etched in the insulating layer to provide a silicon-seed surface from which is grown a selective epitaxial layer extending over the insulating layer within the recesses. After growing a gate oxide on the epitaxial layer, FETs and DRAM capacitors can be formed on the epitaxial layer.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: November 20, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Kheng Chok Tee, Randall Cher Liang Cha, Lap Chan
  • Patent number: 6313008
    Abstract: The invention describes three embodiments of methods for forming a balloon shaped STI trench. The first embodiment begins by forming a barrier layer over a substrate. An isolation opening is formed in the barrier layer. Next, ions are implanted into said substrate through said isolation opening to form a Si damaged or doped first region. The first region is selectively etching to form a hole. The hole is filled with an insulating material to form a balloon shaped shallow trench isolation (STI) region. The substrate has active areas between said balloon shaped shallow trench isolation (STI) regions. The second embodiment differs from the first embodiment by forming a trench in the substrate before the implant. The third embodiment forms a liner in the trench before an isotropic etch of the substrate through the trench.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: November 6, 2001
    Assignee: Chartered Semiconductor Manufacturing Inc.
    Inventors: Ying Keung Leung, Yelehanka Ramachandramurthy Pradeep, Jia Zhen Zheng, Lap Chan, Elgin Quek, Ravi Sundaresan, Yang Pan, James Yong Meng Lee
  • Patent number: 6306715
    Abstract: A method to form a MOS transistor with a narrow channel regions and a wide top (second) gate portion. A gate dielectic layer and a first gate layer are formed over a substrate. A second gate portion is formed over the first gate layer. Spacers are formed on the sidewalls of the second gate portion. In a critical step, we isotropically etch the first gate layer to undercut the second gate portion to form a first gate portion so that the first portion has a width less than the second gate portion. The spacers are removed. Lightly doped drains, sidewall spacers and source/drain regions are formed to complete the device.
    Type: Grant
    Filed: January 8, 2001
    Date of Patent: October 23, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Lap Chan, Elgin Quek, Ravi Sundaresan, Yang Pan, James Yong Meng Lee, Ying Keung Leung, Yelehanka Ramachandramurthy Pradeep, Jia Zhen Zheng
  • Patent number: 6307248
    Abstract: A method for fabricating an anti-fuse cell using an undoped polysilicon film as a mask in defining the anti-fuse window is described. A layer of silicon oxide is provided over the surface of a semiconductor substrate. A first undoped polysilicon layer is deposited overlying the silicon oxide layer. The first undoped polysilicon layer is covered with a photoresist layer patterned to form a mask. The first undoped polysilicon layer and a portion of the silicon oxide layer are etched away where they are not covered by the mask to form a cell opening. The mask and the remaining silicon oxide within the cell opening are removed. An insulating layer is deposited over the surface of the first undoped polysilicon layer and within the cell opening. A second polysilicon layer is deposited overlying the insulating layer and doped. The second polysilicon layer is patterned to form an anti-fuse cell. Gate electrodes and source and drain regions are formed completing the fabrication of the integrated circuit device.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: October 23, 2001
    Assignee: Chartered Semiconductor Manufacturing Company
    Inventors: Che-Chia Wei, Lap Chan, Bob Lee, Poh Suan Tan
  • Patent number: 6306714
    Abstract: A method of fabrication of an elevated source/drain (S/D) for a MOS device. A first insulating layer having a gate opening and source/drain openings is formed over a substrate. We form a LDD resist mask having opening over the source/drain openings over the first insulating layer. Ions are implanted through the source/drain openings. A first dielectric layer is formed on the substrate in the gate opening and source/drain openings. A gate is formed in the gate opening and raised source/drain (S/D) blocks in the source/drain openings. We remove the spacer blocks to form spacer block openings. We form second LDD regions by implanting ions through the spacer block openings. We form second spacer blocks in the spacer block openings. Plug opening are formed through the raised source/drain (S/D) blocks. Contact plugs are formed in the form plug opening.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: October 23, 2001
    Assignee: Chartered Semiconductor Manufacturing Inc.
    Inventors: Yang Pan, James Yongmeng Lee, Ying Keung Leung, Yelehanka Ramachandramurthy Pradeep, Jia Zhen Zheng, Lap Chan, Elgin Quek, Ravi Sundaresan
  • Patent number: 6303418
    Abstract: A method of forming a metal gate structure, on a high k gate insulator layer, for NMOS devices, and simultaneously forming a metal-polysilicon gate structure, on the same high k gate insulator layer, for PMOS devices, has been developed. The method features forming openings in a composite insulator layer, via removal of silicon nitride dummy gate structures that were embedded in a composite insulator layer, with the openings exposing regions of the semiconductor substrate to be used for subsequent NMOS and PMOS channel regions. Deposition of a high k gate insulator layer is followed by deposition of an in situ doped polysilicon layer. After removal of a portion of the in situ doped polysilicon layer located in the NMOS region, a metal layer is deposited on the underlying high k gate insulator layer in the NMOS region, and on the in situ polysilicon layer in the PMOS region.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: October 16, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Cher Liang Cha, Alex See, Lap Chan
  • Patent number: 6303449
    Abstract: A method of manufacturing a self aligned elevated source/drain (S/D). A first insulating layer is formed over a substrate. The first insulating layer having at least a gate opening and source/drain (S/D) openings adjacent to the gate opening. Spacer portions of the first insulating layer define the gate opening. A gate dielectric layer is formed over the substrate in the gate opening. A conductive layer is formed over the substrate. The conductive layer fills the gate opening and the source/drain (S/D) openings. The conductive layer is doped with dopants. The conductive layer is planarized to form a gate over the gate dielectric layer and filling the gate opening and filling the source/drain (S/D) opening to form elevated source/drain (S/D) regions. The conductive layer is preferably planarized so that the top surface of the conductive layer is level with the top surface of the first insulating layer. The spacer portions are removed to form spacer openings.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: October 16, 2001
    Assignee: Chartered Semiconductor Manufacturing Inc.
    Inventors: Yang Pan, James Yong Meng Lee, Ying Keung Leung, Yelehanka Ramachandramurthy Pradeep, Jia Zhen Zheng, Lap Chan, Elgin Kiok Boone Quek, Ravi Sundaresan
  • Patent number: 6300177
    Abstract: A method of forming a gate electrode, comprising the following steps. A semiconductor substrate having an overlying patterned layer exposing a portion of the substrate within active area and patterned layer opening. The patterned layer having exposed sidewalls. Internal spacers are formed over a portion of the exposed substrate portion within the patterned layer opening on the patterned layer exposed sidewalls. The internal spacers being comprised of a WF1 material having a first work function. A planarized gate electrode body is formed within the remaining portion of the patterned layer opening and adjacent to the internal spacers. The gate electrode body being comprised of a WF2 material having a second work function. The internal spacers and the gate electrode body forming the gate electrode.
    Type: Grant
    Filed: January 25, 2001
    Date of Patent: October 9, 2001
    Assignee: Chartered Semiconductor Manufacturing Inc.
    Inventors: Ravi Sundaresan, Yang Pan, James Yong Meng Lee, Ying Keung Leung, Yelehanka Ramachandramurthy Pradeep, Jia Zhen Zheng, Lap Chan, Elgin Quek
  • Patent number: 6300172
    Abstract: A method of fabricating an SOI transistor device comprises the following steps. a silicon semiconductor structure is provided. A silicon oxide layer is formed over the silicon semiconductor structure. A silicon-on-insulator layer is formed over the oxide layer. A well is implanted in the silicon-on-insulator layer. A gate oxide layer is grown over the silicon-on-insulator layer. A polysilicon layer is deposited over the gate oxide layer. The polysilicon layer, gate oxide layer, and silicon oxide layer are patterned and etched to form trenches. The trenches are filled with an isolation material to at least a level even with a top surface of the polysilicon layer to form raised shallow trench isolation regions (STIs). The polysilicon layer is patterned and the non-gate portions are removed polysilicon adjacent the raised STIs forming a gate conductor between the raised STIs with the gate conductor and said raised STIs having exposed sidewalls.
    Type: Grant
    Filed: October 1, 1999
    Date of Patent: October 9, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Ting Cheong Ang, Shyue Pong Quek, Lap Chan, Sang Yee Loong