Patents by Inventor Pang Dow Foo

Pang Dow Foo 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: 6908825
    Abstract: The invention relates to a method of making an integrated circuit inductor that comprises a silicon substrate and an oxide layer on the silicon substrate. In one aspect, the method comprises depositing an inductive loop on the oxide layer, and making a plurality of apertures in the oxide layer beneath the inductive loop. The method also comprises providing a plurality of bridges adjacent the apertures and provided by portions of the oxide layer between an inner region within the inductive loop and an outer region of the oxide layer without the inductive loop, the inductive loop being supported on the bridges. The method comprises forming a trench in the silicon substrate beneath the bridges, to provide an air gap between the inductive loop and the silicon substrate.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: June 21, 2005
    Assignee: Institute of Microelectronics
    Inventors: Shuming Xu, Hanhua Feng, Pang Dow Foo, Bai Xu, Uppili Sridhar
  • Patent number: 6855640
    Abstract: When using hot alkaline etchants such as KOH, the wafer front side, where various devices and/or circuits are located, must be isolated from any contact with the etchant. This has been achieved by using two chambers that are separated from each other by the wafer that is to be etched. Etching solution in one chamber is in contact with the wafer's back surface while deionized water in the other chamber contacts the front surface. The relative liquid pressures in the chambers is arranged to be slightly higher in the chamber of the front surface so that leakage of etchant through a pin hole from back surface to front surface does not occur. As a further precaution, a monitor to detect the etchant is located in the DI water so that, if need be, etching can be terminated before irreparable damage is done.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: February 15, 2005
    Assignee: Institute of Microelectronics
    Inventors: Zhe Wang, Qingxin Zhang, Pang Dow Foo, Hanhua Feng
  • Patent number: 6765300
    Abstract: A microstructure relay is provided, having a body that includes upper and lower portions. The lower portion is formed from a substrate, and the upper portion is formed on the substrate to avoid bonding of the lower portion to the upper portion. A support member is fixed to the body at a first end of the support member to form a cantilever, wherein an upper surface of the support member and a lower surface of the upper portion of the body form a cavity. A first contact region is located on the upper surface at a second end of the support member. The first contact region comprises a first contact, wherein pivoting the support member toward the lower surface causes the first contact to be electrically coupled to a counter contact.
    Type: Grant
    Filed: February 11, 2002
    Date of Patent: July 20, 2004
    Assignees: Tyco Electronics Logistics, AG, Institute of Microelectronics
    Inventors: Dirk Wagenaar, Kay Krupka, Helmut Schlaak, Uppili Sridhar, Victor D. Samper, Pang Dow Foo
  • Patent number: 6670272
    Abstract: A method is described for reducing dishing in a chemical mechanical polishing process performed on a semiconductor wafer having a dielectric layer with trenches and a copper layer deposited over the dielectric layer and filling the trenches in the dielectric layer. The method comprises steps of removing excess copper above the plane of the dielectric surface using a main polishing operation, whereby copper residues are formed above the plane of the dielectric surface, and applying chemical treatment to the surface of the semiconductor wafer in the initial stage of an overpolishing operation, wherein a protective layer over the copper residues and surfaces of copper-filled trenches is formed. The method further comprises steps of removing the copper residues and protective layer thereon above the plane of the dielectric layer in the overpolishing operation, and removing the protective layer over the surfaces of the copper-filled trenches in the overpolishing operation.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: December 30, 2003
    Assignee: Singapore Science Park II
    Inventors: Shaoyu Wu, Joon Mo Kang, Pang Dow Foo
  • Patent number: 6667516
    Abstract: In the prior art LDMOSFET devices capable of handling high power have been made by locating the source contact on the bottom surface of the device, allowing for good heat sinking, with connection to the source region being made through a sinker. However, this structure has poor high frequency characteristics. Also in the prior art, good high frequency performance has been achieved by introducing a dielectric layer immediately below the source/drain regions (SOI) but this structure has poor power handling capabilities. The present invention achieves both good high frequency behavior as well as good power capability in the same device. Instead of inserting a dielectric layer over the entire cross-section of the device, the dielectric layer is limited to being below the heavily doped section of the drain with a small amount of overlap into the lightly doped section. The structure is described in detail together with a process for manufacturing it.
    Type: Grant
    Filed: July 1, 2002
    Date of Patent: December 23, 2003
    Assignee: Institute of Microelectronics
    Inventors: Shuming Xu, Hanhua Feng, Pang-Dow Foo
  • Patent number: 6664596
    Abstract: A novel silicon RF LDMOSFET structure based on the use of a stacked LDD, is disclosed. The LDD has been modified from a single layer of N type material to a stack of three layers. These are upper and lower N type layers with a P type layer between them. The upper N type layer is heavily doped to reduce the on-resistance of the device, while the lower N type layer is lightly doped to reduce the output capacitance, thereby improving the high frequency performance. The middle P layer is heavily doped which allows it to bring about pinch-off of the two N layers, thereby raising the device's breakdown voltage. A process for manufacturing the device, as well as experimental data concerning its performance are also given.
    Type: Grant
    Filed: October 16, 2002
    Date of Patent: December 16, 2003
    Assignee: Institute of Microelectronics
    Inventors: Jun Cai, Pang Dow Foo, Narayanan Balasubramanian
  • Publication number: 20030160022
    Abstract: When using hot alkaline etchants such as KOH, the wafer front side, where various devices and/or circuits are located, must be isolated from any contact with the etchant. This has been achieved by using two chambers that are separated from each other by the wafer that is to be etched. Etching solution in one chamber is in contact with the wafer's back surface while deionized water in the other chamber contacts the front surface. The relative liquid pressures in the chambers is arranged to be slightly higher in the chamber of the front surface so that leakage of etchant through a pin hole from back surface to front surface does not occur. As a further precaution, a monitor to detect the etchant is located in the DI water so that, if need be, etching can be terminated before irreparable damage is done.
    Type: Application
    Filed: February 26, 2002
    Publication date: August 28, 2003
    Applicant: Institute of Microelectronics.
    Inventors: Zhe Wang, Qingxin Zhang, Pang Dow Foo, Hanhua Feng
  • Publication number: 20030085448
    Abstract: A novel silicon RF LDMOSFET structure based on the use of a stacked LDD, is disclosed. The LDD has been modified from a single layer of N type material to a stack of three layers. These are upper and lower N type layers with a P type layer between them. The upper N type layer is heavily doped to reduce the on-resistance of the device, while the lower N type layer is lightly doped to reduce the output capacitance, thereby improving the high frequency performance. The middle P layer is heavily doped which allows it to bring about pinch-off of the two N layers, thereby raising the device's breakdown voltage. A process for manufacturing the device, as well as experimental data concerning its performance are also given.
    Type: Application
    Filed: October 16, 2002
    Publication date: May 8, 2003
    Applicant: INSTITUTE OF MICROELECTRONICS
    Inventors: Jun Cai, Pang Dow Foo, Narayanan Balasubramanian
  • Publication number: 20030071325
    Abstract: The invention relates to a method of making an integrated circuit inductor that comprises a silicon substrate and an oxide layer on the silicon substrate. In one aspect, the method comprises depositing an inductive loop on the oxide layer, and making a plurality of apertures in the oxide layer beneath the inductive loop. The method also comprises providing a plurality of bridges adjacent the apertures and provided by portions of the oxide layer between an inner region within the inductive loop and an outer region of the oxide layer without the inductive loop, the inductive loop being supported on the bridges. The method comprises forming a trench in the silicon substrate beneath the bridges, to provide an air gap between the inductive loop and the silicon substrate.
    Type: Application
    Filed: November 14, 2002
    Publication date: April 17, 2003
    Inventors: Shuming Xu, Han Hua Feng, Pang Dow Foo, Bai Xu, Uppili Sridhar
  • Publication number: 20030054649
    Abstract: A method is described for reducing dishing in a chemical mechanical polishing process performed on a semiconductor wafer having a dielectric layer with trenches and a copper layer deposited over the dielectric layer and filling the trenches in the dielectric layer. The method comprises steps of removing excess copper above the plane of the dielectric surface using a main polishing operation, whereby copper residues are formed above the plane of the dielectric surface, and applying chemical treatment to the surface of the semiconductor wafer in the initial stage of an overpolishing operation, wherein a protective layer over the copper residues and surfaces of copper-filled trenches is formed. The method further comprises steps of removing the copper residues and protective layer thereon above the plane of the dielectric layer in the overpolishing operation, and removing the protective layer over the surfaces of the copper-filled trenches in the overpolishing operation.
    Type: Application
    Filed: October 12, 2001
    Publication date: March 20, 2003
    Inventors: Shaoyu Wu, Joon Mo Kang, Pang Dow Foo
  • Publication number: 20030040174
    Abstract: A method for photolithographic patterning in a via-first dual damascene process involving the use of a low-K dielectric material as an insulation layer on a wafer substrate during the fabrication of an integrated circuit is described. The method includes filling an aperture etched into an insulation layer on a wafer substrate with a fill-in material for isolating the insulation layer from a photoresist layer deposited thereafter and depositing a photoresist layer on the insulation layer. The method further includes exposing and developing the photoresist layer for providing a photoresist mask pattern for subsequent etching of the insulation layer; and removing the fill-in material from the aperture.
    Type: Application
    Filed: December 19, 2001
    Publication date: February 27, 2003
    Inventors: Cher Huan Tan, Moitreyee Mukherjee-Roy, Pang Dow Foo
  • Patent number: 6503847
    Abstract: A method of forming bonds between similar and dissimilar material surfaces particularly the surfaces of silicon wafers having various devices disposes thereon, wherein such bonds can be formed at room temperature and do not require the application of high pressures or voltages. The bonding material is polydimethylsiloxane, which is transparent and bio-compatible.
    Type: Grant
    Filed: April 26, 2001
    Date of Patent: January 7, 2003
    Assignee: Institute of Microelectronics
    Inventors: Yu Chen, Quanbo Zou, Uppili Sridhar, Pang Dow Foo
  • Publication number: 20020197774
    Abstract: In the prior art LDMOSFET devices capable of handling high power have been made by locating the source contact on the bottom surface of the device, allowing for good heat sinking, with connection to the source region being made through a sinker. However, this structure has poor high frequency characteristics. Also in the prior art, good high frequency performance has been achieved by introducing a dielectric layer immediately below the source/drain regions (SOI) but this structure has poor power handling capabilities. The present invention achieves both good high frequency behavior as well as good power capability in the same device. Instead of inserting a dielectric layer over the entire cross-section of the device, the dielectric layer is limited to being below the heavily doped section of the drain with a small amount of overlap into the lightly doped section. The structure is described in detail together with a process for manufacturing it.
    Type: Application
    Filed: July 1, 2002
    Publication date: December 26, 2002
    Applicant: INSTITUTE OF MICROELECTRONICS
    Inventors: Shuming Xu, Hanhua Feng, Pang-Dow Foo
  • Patent number: 6495903
    Abstract: An inductor has a spiral aluminum track deposited on an oxide layer over a silicon substrate. The substrate is etched away to form a trench, which extends around beneath the track and provides an air gap having a low dielectric constant. The oxide layer has an inner region within the track, an outer region outside the track and a bridging region extending between the other regions. The bridging region is comprised of intact bridges and gaps therebetween, which are open to the trench and through which an etchant has access to the silicon substrate to form the trench by etching.
    Type: Grant
    Filed: December 13, 2000
    Date of Patent: December 17, 2002
    Assignee: Institute of Microelectronics
    Inventors: Shuming Xu, Hanhua Feng, Pang Dow Foo, Bai Xu, Uppili Sridhar
  • Patent number: 6489203
    Abstract: A novel silicon RF LDMOSFET structure based on the use of a stacked LDD, is disclosed. The LDD has been modified from a single layer of N type material to a stack of three layers. These are upper and lower N type layers with a P type layer between them. The upper N type layer is heavily doped to reduce the on-resistance of the device, while the lower N type layer is lightly doped to reduce the output capacitance, thereby improving the high frequency performance. The middle P layer is heavily doped which allows it to bring about pinch-off of the two N layers, thereby raising the device's breakdown voltage. A process for manufacturing the device, as well as experimental data concerning its performance are also given.
    Type: Grant
    Filed: May 7, 2001
    Date of Patent: December 3, 2002
    Assignee: Institute of Microelectronics
    Inventors: Jun Cai, Pang Dow Foo, Narayanan Balasubramanian
  • Publication number: 20020164844
    Abstract: A novel silicon RF LDMOSFET structure based on the use of a stacked LDD, is disclosed. The LDD has been modified from a single layer of N type material to a stack of three layers. These are upper and lower N type layers with a P type layer between them. The upper N type layer is heavily doped to reduce the on-resistance of the device, while the lower N type layer is lightly doped to reduce the output capacitance, thereby improving the high frequency performance. The middle P layer is heavily doped which allows it to bring about pinch-off of the two N layers, thereby raising the device's breakdown voltage. A process for manufacturing the device, as well as experimental data concerning its performance are also given.
    Type: Application
    Filed: May 7, 2001
    Publication date: November 7, 2002
    Applicant: Institute of Microelectronics
    Inventors: Jun Cai, Pang Dow Foo, Narayanan Balasubramanian
  • Publication number: 20020160582
    Abstract: A method for forming bonds between similar and dissimilar material surfaces, particularly the surfaces of silicon wafers having various devices disposed thereon, wherein such bonds can be formed at room temperature and do not require the application of high pressures or voltages. The bonding material is polydimethylsiloxane, which is transparent and bio-compatible.
    Type: Application
    Filed: April 26, 2001
    Publication date: October 31, 2002
    Applicant: Institute of Microelectronics
    Inventors: Yu Chen, Quanbo Zou, Uppili Sridhar, Pang Dow Foo
  • Patent number: 6461902
    Abstract: In the prior art LDMOSFET devices capable of handling high power have been made by locating the source contact on the bottom surface of the device, allowing for good heat sinking, with connection to the source region being made through a sinker. However, this structure has poor high frequency characteristics. Also in the prior art, good high frequency performance has been achieved by introducing a dielectric layer immediately below the source/drain regions (SOI) but this structure has poor handling capabilities. The present invention achieves both good high frequency behavior as well as good power capability in the same device. Instead of inserting a dielectric layer over the entire cross-section of the device, the dielectric layer is limited to being below the heavily doped section of the drain with a small amount of overlap into the lightly doped section. The structure is described in detail together with a process for manufacturing it.
    Type: Grant
    Filed: July 18, 2000
    Date of Patent: October 8, 2002
    Assignee: Institute of Microelectronics
    Inventors: Shuming Xu, Hanhua Feng, Pang-Dow Foo
  • Patent number: 6436810
    Abstract: The current invention teaches the use of e-beam patterning techniques for forming contact and via holes of diameter less than about 0.15 microns down to 0.05 microns. E-beam lithography has higher resolution (down to 30-50 nanometers) as compared to 130-150 nanometer when using deep ultra violet (DUV) photolithography patterning techniques. In addition the invention uses a mix and match approach by employing a conventional I-line, or deep UV, resist to form the trench pattern and e-beam lithography tools to form the contact and vial hole patterns. A simplified process scheme is developed where contact/via holes are formed first on solvent developable e-beam resist and the trench pattern is formed on aqueous developable photoresist coated on top of the e-beam resist.
    Type: Grant
    Filed: September 27, 2000
    Date of Patent: August 20, 2002
    Assignee: Institute of Microelectronics
    Inventors: Rakesh Kumar, Leong Tee Koh, Pang Dow Foo
  • Patent number: 6383855
    Abstract: A bipolar complementary metal oxide semiconductor device has a c-well fabricated using profile engineering (a multi-energy implant using accurate dosages and energies determined by advance simulation) to provide a higher c-well implant dose while creating a narrow region with relatively low concentration in the collector depletion range to avoid low base-collector breakdown. This achieves a much lower collector series resistance to pull-up a frequency response, a collector sheet resistance which can be as low as 150 &OHgr;/sq., and fT may be increased to 20 GHz or higher.
    Type: Grant
    Filed: November 4, 1998
    Date of Patent: May 7, 2002
    Assignee: Institute of Microelectronics
    Inventors: Minghui Gao, Haijun Zhao, Abhijit Bandyopadhyay, Pang Dow Foo