Patents by Inventor Eng-Hua Lim

Eng-Hua Lim 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).

  • 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
  • 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: 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: 6383922
    Abstract: A method for forming a thermally stable cobalt disilicide film in the fabrication of an integrated circuit is described. A semiconductor substrate is provided having silicon regions to be silicided. A cobalt layer is deposited overlying the silicon regions to be silicided. A capping layer is deposited overlying the cobalt layer. The substrate is subjected to a first rapid thermal anneal whereby the cobalt is transformed to cobalt monosilicide where it overlies the silicon regions and wherein the cobalt not overlying the silicon regions is unreacted. The unreacted cobalt layer and the capping layer are removed. A titanium layer is deposited overlying the cobalt monosilicide layer. Thereafter the substrate is subjected to a second rapid thermal anneal whereby the cobalt monosilicide is transformed to cobalt disilicide. The titanium layer provides titanium atoms which diffuse into the cobalt disilicide thereby increasing its thermal stability.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: May 7, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Bei Chao Zhang, Chung Woh Lai, Eng Hua Lim, Mei Sheng Zhou, Peter Chew, Arthur Ang
  • Patent number: 6350661
    Abstract: An improved and new process for fabricating MOSFET's in shallow trench isolation (STI), with sub-quarter micron ground rules, includes a passivating trench cap layer of silicon nitride. The silicon nitride passivating trench cap is utilized in the formation of borderless or “unframed” electrical contacts, without reducing the poly to poly spacing. Borderless contacts are formed, wherein contact openings are etched in an interlevel dielectric (ILD) layer over both an active region (P-N junction) and an inactive trench isolation region. During the contact hole opening, a selective etch process is utilized which etches the ILD layer, while the protecting passivating silicon nitride trench cap layer remains intact protecting the P-N junction at the edge of trench region. Subsequent processing of conductive tungsten metal plugs are prevented from shorting by the passivating trench cap.
    Type: Grant
    Filed: June 18, 2001
    Date of Patent: February 26, 2002
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chong Wee Lim, Eng Hua Lim, Soh Yun Siah, Kong Hean Lee, Chun Hui Low
  • Publication number: 20010031540
    Abstract: An improved and new process for fabricating MOSFET's in shallow trench isolation (STI), with sub-quarter micron ground rules, includes a passivating trench cap layer of silicon nitride. The silicon nitride passivating trench cap is utilized in the formation of borderless or “unframed” electrical contacts, without reducing the poly to poly spacing. Borderless contacts are formed, wherein contact openings are etched in an interlevel dielectric (ILD) layer over both an active region (P-N junction) and an inactive trench isolation region. During the contact hole opening, a selective etch process is utilized which etches the ILD layer, while the protecting passivating silicon nitride trench cap layer remains intact protecting the P-N junction at the edge of trench region. Subsequent processing of conductive tungsten metal plugs are prevented from shorting by the passivating trench cap.
    Type: Application
    Filed: June 18, 2001
    Publication date: October 18, 2001
    Applicant: CHARTERED SEMICONDUCTOR MANUFACTURING LTD.
    Inventors: Chong Wee Lim, Eng Hua Lim, Soh Yun Siah, Kong Hean Lee, Chun Hui Low
  • Patent number: 6297126
    Abstract: An improved and new process for fabricating MOSFET's in shallow trench isolation (STI), with sub-quarter micron ground rules, includes a passivating trench cap layer of silicon nitride. The silicon nitride passivating trench cap is utilized in the formation of borderless or “unframed” electrical contacts, without reducing the poly to poly spacing. Borderless contacts are formed, wherein contact openings are etched in an interlevel dielectric (ILD) layer over both an active region (P-N junction) and an inactive trench isolation region. During the contact hole opening, a selective etch process is utilized which etches the ILD layer, while the protecting passivating silicon nitride trench cap layer remains intact protecting the P-N junction at the edge of trench region. Subsequent processing of conductive tungsten metal plugs are prevented from shorting by the passivating trench cap.
    Type: Grant
    Filed: July 12, 1999
    Date of Patent: October 2, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chong Wee Lim, Eng Hua Lim, Soh Yun Siah, Kong Hean Lee, Chun Hui Low
  • Patent number: 6271133
    Abstract: A new method is established to form different silicide layers over the top of the gate electrode and the surface of the source/drain regions. A thin layer of TiSi2 is formed over the source/drain regions by depositing a layer of titanium and annealing this layer with the silicon substrate. The gate electrode is created as a recessed electrode, in the top recession of the electrode a layer of CoSi2 is formed by depositing a layer of cobalt over the gate electrode. This layer of COSi2 serves as the electrical gate contact point.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: August 7, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chong Wee Lim, Eng Hua Lim, Kin Leong Pey, Soh Yun Siah, Chun Hui Low
  • Patent number: 6265302
    Abstract: An improved and new process for fabricating MOSFET's in shallow trench isolation (STI), with sub-quarter micron ground rules, includes a passivating trench liner of silicon nitride. The silicon nitride passivating liner is utilized in the formation of borderless or “unframed” electrical contacts, without reducing the poly to poly spacing. Borderless contacts are formed, wherein contact openings are etched in an interlevel dielectric (ILD) layer over both an active region (P-N junction) and an inactive trench isolation region. During the contact hole opening, a selective etch process is utilized which etches the ILD layer, while the protecting passivating silicon nitride liner remains intact protecting the P-N junction at the edge of trench region. Subsequent processing of conductive tungsten metal plugs are prevented from shorting by the passivating trench liner.
    Type: Grant
    Filed: July 12, 1999
    Date of Patent: July 24, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Chong Wee Lim, Eng Hua Lim, Soh Yun Siah, Kong Hean Lee, Chun Hui Low
  • Patent number: 6228727
    Abstract: A method of fabricating shallow trench isolations has been achieved. A semiconductor substrate is provided. A pad oxide layer is grown overlying the semiconductor substrate. A silicon nitride layer is deposited. The silicon nitride layer and the pad oxide layer are patterned to form a hard mask. The openings in the hard mask correspond to planned trenches in the semiconductor substrate. A silicon dioxide layer is deposited overlying the silicon nitride layer and the semiconductor substrate. The silicon dioxide layer is anisotropically etched to form sidewall spacers on the inside of the openings of the hard mask. The semiconductor substrate is etched to form the trenches. The sidewall spacers are etched away. The semiconductor substrate is sputter etched to round the corners of the trenches. An oxide trench lining layer is grown overlying the semiconductor substrate. A trench fill layer is deposited overlying the silicon nitride layer and filling the trenches.
    Type: Grant
    Filed: September 27, 1999
    Date of Patent: May 8, 2001
    Assignee: Chartered Semiconductor Manufacturing, Ltd.
    Inventors: Chong Wee Lim, Soh Yun Siah, Eng Hua Lim, Kong-Hean Lee, Chun Hui Low
  • Patent number: 6165871
    Abstract: A method for forming a stepped shallow trench isolation is described. A pad oxide layer is deposited on the surface of a semiconductor substrate. A first nitride layer is deposited overlying the pad oxide layer. The first nitride layer is etched through where it is not covered by a mask to provide an opening to the pad oxide layer. A first trench is etched through the pad oxide layer within the opening and into the semiconductor substrate. A second nitride layer is deposited overlying the first nitride layer and filling the first trench. Simultaneously, the second nitride layer is anisotropically etched to form nitride spacers on the sidewalls of the first trench and the semiconductor substrate is etched into where it is not covered by the spacers to form a second trench. Ions are implanted into the semiconductor substrate underlying the second trench. The first and second trenches are filled with an oxide layer.
    Type: Grant
    Filed: July 16, 1999
    Date of Patent: December 26, 2000
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Eng Hua Lim, Chong Wee Lim, Soh Yun Siah, Kong Hean Lee, Pei Ching Lee
  • Patent number: 5956137
    Abstract: An in-line non-destructive method is described for identifying phases in a micro-structure such as a fine line pattern. This is accomplished by observing the Raman spectrum of the micro-structure. A particular application is a silicide layer, prepared using the SALICIDE process, where the crystal phases before and after Rapid Thermal Anneal are often different. This is reflected by the appearance of different lines in the Raman spectra so that the fraction of each phase can be determined. If the silicide layer agglomerated during the anneal, this is also detected by the Raman spectrum. The method has been used successfully down to line widths of about 0.35 microns.
    Type: Grant
    Filed: November 5, 1998
    Date of Patent: September 21, 1999
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Eng Hua Lim, Kin-Leong Pey, Harianto Wong, Kong Hean Lee