Patents by Inventor Len Mei

Len Mei 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: 8125020
    Abstract: A memory device includes a cell stack and a select gate formed adjacent to the cell stack. The cell stack includes a tunneling dielectric layer, a charge storage layer, a blocking dielectric layer, and a control gate. Applying a positive bias to the control gate, the select gate and the source of the device injects negative charges from a channel region of a substrate by hot electron injection through the tunneling dielectric layer at a location near a gap between the select gate and the control gate into the charge storage layer to store negative charges in the charge storage layer. Applying a negative bias to the control gate directly tunnels positive charges from the channel region of the substrate through the tunneling dielectric layer and into the charge storage layer to store positive charges in the charge storage layer.
    Type: Grant
    Filed: October 15, 2007
    Date of Patent: February 28, 2012
    Assignee: Promos Technologies Pte. Ltd
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20100323511
    Abstract: Charge-trapping dielectric (160) in a nonvolatile memory cell is recessed from under the control gate's edge and/or from an edge of a substrate isolation region. The recessed geometry serves to reduce or eliminate charge trapping in regions from which the charge may be difficult to erase.
    Type: Application
    Filed: August 31, 2010
    Publication date: December 23, 2010
    Inventors: Yue-Song He, Len Mei
  • Patent number: 7816726
    Abstract: Charge-trapping dielectric (160) in a nonvolatile memory cell is recessed from under the control gate's edge and/or from an edge of a substrate isolation region. The recessed geometry serves to reduce or eliminate charge trapping in regions from which the charge may be difficult to erase.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: October 19, 2010
    Assignee: ProMOS Technologies Pte. Ltd.
    Inventors: Yue-Song He, Len Mei
  • Patent number: 7808032
    Abstract: A floating gate memory cell's channel region (104) is at least partially located in a fin-like protrusion (110P) of a semiconductor substrate. The floating gate's top surface may come down along at least two sides of the protrusion to a level below the top (110P-T) of the protrusion. The control gate's bottom surface may also comes down to a level below the top of the protrusion. The floating gate's bottom surface may comes down to a level below the top of the protrusion by at least 50% of the protrusion's height. The dielectric (120) separating the floating gate from the protrusion can be at least as thick at the top of the protrusion as at a level (L2) which is below the top of the protrusion by at least 50% of the protrusion's height. A very narrow fin or other narrow feature in memory and non-memory integrated circuits can be formed by providing a first layer (320) and then forming spacers (330) from a second layer without photolithography on sidewalls of features made from the first layer.
    Type: Grant
    Filed: June 25, 2008
    Date of Patent: October 5, 2010
    Assignee: ProMOS Technologies Pte. Ltd.
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20090321806
    Abstract: Substrate isolation regions (570) initially protrude upward above a semiconductor substrate (520) but are later etched down. Before they are etched down, floating gate layer (590) is deposited and etched or polished off the top surfaces of the substrate isolation regions. The floating gate layer thus has upward protrusions overlying sidewalls of the substrate isolation regions. When the substrate isolation regions are etched down, the floating gate layer's upward protrusions' outer sidewalls become exposed. The upward protrusions serve to increase the capacitance between the floating and control gates. The floating gates' bottom surfaces are restricted to the active areas (564) not to overlie the substrate isolation regions. Other features are also provided.
    Type: Application
    Filed: June 26, 2008
    Publication date: December 31, 2009
    Inventors: Len Mei, Yue-Song He
  • Publication number: 20090256221
    Abstract: A method for forming very small isolated dots of a target material, e.g., a ferromagnetic material or phase change material, on a substrate includes providing a substrate having a layer of the target material disposed on a surface thereof, etching the layer of target material so as to form a plurality of lines of the material on the surface of the substrate, and etching the lines of the target material so as to form a rectangular matrix of substantially similar, very small isolated dots of the target material on the substrate. By the successive formation of orthogonally intersecting linear patterns on the substrate, including the formation and use of “hard” etch masks, spacer approach and selective etching techniques, the method enables very small (<65 nm) isolated dots of the target material to be formed on the substrate reliably and with the use of conventional 193 nm wavelength photolithographic methods and apparatus.
    Type: Application
    Filed: April 11, 2008
    Publication date: October 15, 2009
    Inventors: Len Mei, Yue-Song He
  • Publication number: 20090251972
    Abstract: Charge-trapping dielectric (160) in a nonvolatile memory cell is recessed from under the control gate's edge and/or from an edge of a substrate isolation region. The recessed geometry serves to reduce or eliminate charge trapping in regions from which the charge may be difficult to erase.
    Type: Application
    Filed: April 3, 2008
    Publication date: October 8, 2009
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20090184359
    Abstract: A memory device having a cell stack and a select gate formed adjacent to the cell stack. The cell stack includes a first trap-free-nitride layer formed on a channel region of a substrate, a second nitride layer formed on the first nitride layer, an oxide layer formed on the second nitride layer, a control gate formed on the high-K oxide layer, and a poly spacer as the select gate formed adjacent to the control gate.
    Type: Application
    Filed: January 22, 2008
    Publication date: July 23, 2009
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20090159957
    Abstract: Charge-trapping dielectric (160) in a nonvolatile memory cell is recessed from under the control gate's edge and/or from an edge of a substrate isolation region. The recessed geometry serves to reduce or eliminate charge trapping in regions from which the charge may be difficult to erase.
    Type: Application
    Filed: December 20, 2007
    Publication date: June 25, 2009
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20090101961
    Abstract: The present disclosure provides a memory device having a cell stack and a select gate formed adjacent to the cell stack. The cell stack includes a tunneling dielectric layer, a charge storage layer, a blocking dielectric layer, a tantalum-nitride layer, and a control gate layer. When a positive bias is applied to the control gate and the select gate, negative charges are injected from a channel region of a substrate through the tunneling dielectric layer and into the charge storage layer to thereby store the negative charges in the charge storage layer. When a negative bias is applied to the control gate, negative charges are tunneled from the charge storage layer to the channel region of the substrate through the tunneling dielectric layer.
    Type: Application
    Filed: October 22, 2007
    Publication date: April 23, 2009
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20090096013
    Abstract: A memory device includes a cell stack and a select gate formed adjacent to the cell stack. The cell stack includes a tunneling dielectric layer, a charge storage layer, a blocking dielectric layer, and a control gate. Applying a positive bias to the control gate, the select gate and the source of the device injects negative charges from a channel region of a substrate by hot electron injection through the tunneling dielectric layer at a location near a gap between the select gate and the control gate into the charge storage layer to store negative charges in the charge storage layer. Applying a negative bias is to the control gates directly tunnels positive charges from the channel region of the substrate through the tunneling dielectric layer and into the charge storage layer to store positive charges in the charge storage layer.
    Type: Application
    Filed: October 15, 2007
    Publication date: April 16, 2009
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20090085069
    Abstract: In a NAND-type nonvolatile reprogrammable memory array, inter-cell coupling resistance between adjoining memory cells is reducing by forming metal silicide insets embedded in the diffusion zone of the inter-cell coupling region. The diffusion zone includes a shallow implant region and a deep implant region. In one embodiment, the shallow implant region defines shallow source/drain regions for floating gate transistors of the memory cells. The size of the metal silicide insets are controlled to not compromise isolation PN junctions defined by the shallow and deep implant region. In one embodiment, the metal silicide insets include nickel.
    Type: Application
    Filed: September 27, 2007
    Publication date: April 2, 2009
    Inventors: Len MEI, Yue-Song HE
  • Patent number: 7452776
    Abstract: A floating gate memory cell's channel region (104) is at least partially located in a fin-like protrusion (110P) of a semiconductor substrate. The floating gate's top surface may come down along at least two sides of the protrusion to a level below the top (110P-T) of the protrusion. The control gate's bottom surface may also comes down to a level below the top of the protrusion. The floating gate's bottom surface may comes down to a level below the top of the protrusion by at least 50% of the protrusion's height. The dielectric (120) separating the floating gate from the protrusion can be at least as thick at the top of the protrusion as at a level (L2) which is below the top of the protrusion by at least 50% of the protrusion's height. A very narrow fin or other narrow feature in memory and non-memory integrated circuits can be formed by providing a first layer (320) and then forming spacers (330) from a second layer without photolithography on sidewalls of features made from the first layer.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: November 18, 2008
    Assignee: ProMOS Technoloies Pte. Ltd.
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20080265305
    Abstract: A floating gate memory cell's channel region (104) is at least partially located in a fin-like protrusion (110P) of a semiconductor substrate. The floating gate's top surface may come down along at least two sides of the protrusion to a level below the top (110P-T) of the protrusion. The control gate's bottom surface may also comes down to a level below the top of the protrusion. The floating gate's bottom surface may comes down to a level below the top of the protrusion by at least 50% of the protrusion's height. The dielectric (120) separating the floating gate from the protrusion can be at least as thick at the top of the protrusion as at a level (L2) which is below the top of the protrusion by at least 50% of the protrusion's height. A very narrow fin or other narrow feature in memory and non-memory integrated circuits can be formed by providing a first layer (320) and then forming spacers (330) from a second layer without photolithography on sidewalls of features made from the first layer.
    Type: Application
    Filed: June 25, 2008
    Publication date: October 30, 2008
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20080266949
    Abstract: A floating gate memory cell's channel region (104) is at least partially located in a fin-like protrusion (110P) of a semiconductor substrate. The floating gate's top surface may come down along at least two sides of the protrusion to a level below the top (110P-T) of the protrusion. The control gate's bottom surface may also comes down to a level below the top of the protrusion. The floating gate's bottom surface may comes down to a level below the top of the protrusion by at least 50% of the protrusion's height. The dielectric (120) separating the floating gate from the protrusion can be at least as thick at the top of the protrusion as at a level (L2) which is below the top of the protrusion by at least 50% of the protrusion's height. A very narrow fin or other narrow feature in memory and non-memory integrated circuits can be formed by providing a first layer (320) and then forming spacers (330) from a second layer without photolithography on sidewalls of features made from the first layer.
    Type: Application
    Filed: April 24, 2007
    Publication date: October 30, 2008
    Inventors: Yue-Song He, Len Mei
  • Publication number: 20050205411
    Abstract: A physical vapor deposition apparatus is provided. The physical vapor deposition apparatus comprises: a reaction chamber; and an electromagnet magnetron device disposed above and outside said reaction chamber, wherein when performing a physical vapor deposition process, the magnetic poles of said electromagnet magnetron device are reversed in-situ to reduce the possibility of asymmetric deposition of the thin film on the sidewalls of the opening.
    Type: Application
    Filed: July 29, 2004
    Publication date: September 22, 2005
    Inventors: Tai-Yuan Chen, Len Mei
  • Patent number: 6495411
    Abstract: A method for fabricating deep-submicron DRAMs containing a deep trench capacitor with enlarged sidewall surface for improved storage capacitance. It includes the main steps of: (a) forming a silicon substrate having a (110) crystalline plane and a (111) crystalline plane; (b) forming a vertically extending deep trench into a crystalline silicon substrate; (c) filling the deep trench with a first dielectric material to form a first dielectric filler layer; (d) etching back the first dielectric filler layer to a first depth; (e) forming a dielectric collar from a second dielectric material which hangs on the sidewall of the deep trench extending from the opening of the trench to the first depth; (f) removing the first dielectric filler layer with a selective etching process; and (g) under a carefully timed exposure, using an isotropic etching solution which has high etching rate in the (110) plane and low etching rate in the (111) plane to form a roughened surface on the bottom surface of the deep trench.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: December 17, 2002
    Assignees: ProMos Technology Inc., Mosel Vitelic Inc., Siemens AG
    Inventor: Len Mei
  • Patent number: 6232171
    Abstract: A method for fabricating deep-submicron vertically arranged capacitors is disclosed which allows the capacitor to enjoy an enhanced sidewall surface so as to attain a capacitance of 40 pF or more.
    Type: Grant
    Filed: June 8, 1999
    Date of Patent: May 15, 2001
    Assignees: ProMOS Technology, Inc., Mosel Vitelic Inc., Siemens AG
    Inventor: Len Mei
  • Patent number: 6007405
    Abstract: A chemical mechanical polisher for polishing a surface of a semiconductor wafer is disclosed. The polisher comprises: a polishing table for holding a polishing pad; a rotatable wafer chuck for holding said semiconductor wafer against said polishing pad; an electrical lapping guide secured to said wafer chuck, said electrical lapping guide comprising: a polishable resistive sensor that has a variable resistance dependent upon the amount of material removed from said resistive sensor during polishing; and a bias means for applying a bias to said resistive sensor such that said resistive sensor is in contact with said polishing pad during polishing; a resistance sensing means for determining said variable resistance of said resistive sensor; and a microprocessor for determining the amount of material polished from said resistive sensor based upon said variable resistance.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: December 28, 1999
    Assignee: ProMOS Technologies, Inc.
    Inventor: Len Mei