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).

  • Patent number: 6284590
    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 first metal layer is deposited over the insulating layer. A capacitor dielectric layer is deposited overlying the first metal layer. A second metal layer is deposited overlying the capacitor dielectric layer and patterned to form a top metal electrode. A flowable material layer is deposited overlying the capacitor dielectric and the top metal electrode and anisotropically etched away to leave spacers on sidewalls of the top metal electrode. A photoresist mask is formed overlying the capacitor dielectric and the top metal electrode wherein the spacers provide extra photoresist thickness at the sidewalls of the top metal layer.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: September 4, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Randall Cher Liang Cha, Cheng Yeow Ng, Shao-Fu Sanford Chu, Tae Jong Lee, Chua Chee Tee
  • Patent number: 6284610
    Abstract: A method for siliciding source/drain junctions is described wherein compressive stress of the underlying silicon is avoided by the insertion of a buffer layer between the silicide and the silicon. A gate electrode and associated source/drain extensions are provided in and on a semiconductor substrate. A buffer oxide layer is deposited overlying the semiconductor substrate and the gate electrode. A polysilicon layer is deposited overlying the buffer oxide layer. The polysilicon layer will form the source/drain junctions and silicon source. The source/drain junctions are silicided whereby the buffer oxide layer provides compressive stress relief during the siliciding.
    Type: Grant
    Filed: September 21, 2000
    Date of Patent: September 4, 2001
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Randall Cher Liang Cha, Chee Tee Chua, Kin Leong Pey, Lap Chan
  • Patent number: 6252277
    Abstract: Formation of a MOSFET with a polysilicon gate electrode embedded within a silicon trench is described. The MOSFET retains all the features of conventional MOSFETs with photolithographically patterned polysilicon gate electrodes, including robust LDD (lightly doped drain) regions formed in along the walls of the trench. Because the gate dielectric is never exposed to plasma etching or aqueous chemical etching, gate dielectric films of under 100 Angstroms may be formed without defects. The problems of over etching, and substrate spiking which are encountered in the manufacture of photolithographically patterned polysilicon gate electrodes do not occur. The entire process utilizes only two photolithographic steps. The first step defines the silicon active area by patterning a field isolation and the second defines a trench within the active area wherein the device is formed.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: June 26, 2001
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Lap Chan, Cher Liang Cha, Eng Fong Chor, Gong Hao, Teck Koon Lee
  • Patent number: 6221727
    Abstract: A new method of fabricating an inductor utilizing air as an underlying barrier in the manufacturing of integrated circuits is described. A field oxide region is formed in and on a semiconductor substrate and then removed whereby a well is left in the semiconductor substrate. A polish stop layer is deposited over the substrate and within the well. The polish stop layer is covered and the well filled with a spin-on-glass layer. The spin-on-glass layer is polished back to the polish stop layer. The said polish stop layer is removed. A first oxide layer is deposited overlying the spin-on-glass layer and the semiconductor substrate and is patterned using an inductor reticle whereby a plurality of openings are made through the first oxide layer to the spin-on-glass layer. All of the spin-on-glass layer within the well is removed through the plurality of openings.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: April 24, 2001
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Lap Chan, Johnny Kok Wai Chew, Cher Liang Cha, Chee Tee Chua
  • Patent number: 6207534
    Abstract: A method of forming trenches having different depths for use in shallow trench isolations is achieved. Dishing problems due to isolation oxide thinning over wide trenches is eliminated. A silicon substrate is provided. A pad oxide is grown. A polishing stop of silicon nitride is deposited. An oxide layer is grown overlying the silicon substrate. The oxide layer, polishing stop layer, and pad oxide layer are etched through to the silicon substrate to form openings for planned first trenches. A polysilicon layer is deposited overlying the oxide layer and filling the openings for the planned first trenches. The polysilicon layer is polished down to the top surface of the oxide layer such that the polysilicon layer remains only in the openings of the planned first trenches. The oxide layer, polishing stop layer, and pad oxide layer are etched through to the silicon substrate to form openings for planned second trenches.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: March 27, 2001
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Lap Chan, Cher Liang Cha, Teck Koon Lee
  • Patent number: 6150232
    Abstract: A method for creating low intra-level dielectric interface between conducting lines using conventional deposition and etching processes. A layer of conducting lines is formed interspersed with dielectric material. A dummy, high-density pattern of low k dielectric material is created on top of this layer. The dielectric material between the metal lines is removed. The dummy high-density pattern is interconnected, deposited on top of this interconnected layer is a low k dielectric to form an inter layer dielectric.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: November 21, 2000
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Lap Chan, Cher Liang Cha, Kok Keng Ong, Kheng Chok Tee
  • Patent number: 6140197
    Abstract: A new method of fabricating an inductor utilizing air as an underlying barrier in the manufacture of integrated circuits is described. A metal line is provided overlying a dielectric layer on a semiconductor substrate. An intermetal dielectric layer is deposited overlying the metal line and the dielectric layer. The intermetal dielectric layer is patterned whereby a plurality of openings are made through the intermetal dielectric layer to the semiconductor substrate. Thereafter, an oxide layer is deposited overlying the intermetal dielectric layer and capping the plurality of openings thereby forming air gaps within the intermetal dielectric layer. A metal plug is formed through the oxide layer and the intermetal dielectric layer to the metal line.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: October 31, 2000
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Shau-Fu Sanford Chu, Kok Wai Johnny Chew, Chee Tee Chua, Cher Liang Cha
  • Patent number: 6096604
    Abstract: This invention relates to the new reversed flash memory device which has improved electrical performance, yield and reliability because of better control of the dielectric interfaces resulting from first making the poly 2 control gate within the silicon substrate. The reverse structure is novel, as are the described process methods for forming the reverse stacking order.Shallow trenched isolation (STI) is first formed in the p-silicon substrate and encompasses the poly 2 control gate region; then the interpoly dielectric is grown/deposited on that single crystal silicon substrate. The floating poly 1 is formed on top of this uniform interpoly dielectric that has well-controlled surface smoothness. The tunnel oxide layer is formed on the floating poly 1 layer, and the source/drain is implanted on a straddling additional poly layer. There are fewer edges and associated stress weaknesses in the dielectric breakdown of both the reversed interpoly dielectric and the floating tunnel oxide.
    Type: Grant
    Filed: August 4, 1999
    Date of Patent: August 1, 2000
    Assignees: Chartered Semiconductor Manufacturing Ltd, Nanyang Technological University of Singapore, Institute of Microelectronics
    Inventors: Cher Liang Cha, Anqing Zhang, Zhifeng Joseph Xie, Eng Fong Chor
  • Patent number: 6051467
    Abstract: 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 semiconductor substrate. A first polysilicon layer is deposited overlying the gate oxide layer. The first polysilicon layer is etched away where it is not covered by a mask 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: Grant
    Filed: April 2, 1998
    Date of Patent: April 18, 2000
    Assignees: Chartered Semiconductor Manufacturing, Ltd., National University of Singapore
    Inventors: Lap Chan, Cher Liang Cha