Patents by Inventor Yuan-Ping Lee

Yuan-Ping Lee 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: 6156654
    Abstract: Methods are disclosed for forming ultra-thin (.about.300-.ANG.), uniform and stoichiometric C54-titanium silicide with a Ti film thickness of 200-300 .ANG. using pulsed laser salicidation. The invention achieves this by preferably step-scanning from die to die, across the wafer using laser pulses with an optical fluence (laser energy) ranging from 0.1 to 0.2 J/cm.sup.2 for approximately 23 nanoseconds per pulse. The source of radiation can be a XeCl or KrF excimer laser, or one in which the laser's wavelength is chosen such that the laser energy is absorbed the most by the refractory metal, i.e. titanium (Ti), cobalt (Co) or nickel (Ni). The laser beam size is typically die-size or can be fine tuned to 1 to 100 .mu.m and can be optimized to reduce the intensity variation across the laser spot diameter. At each position between 1 to 100 pulses can be emitted on the wafer. Localized heating is possible with the ability to establish the ambient temperature at or below 200.degree. C.
    Type: Grant
    Filed: December 7, 1998
    Date of Patent: December 5, 2000
    Assignees: Chartered Semiconductor Manufacturing Ltd., National University of Singapore
    Inventors: Chaw Sing Ho, Yuan Ping Lee, Chan Lap, Yong Feng Lu, R. P.G. Karunasiri
  • Patent number: 6121130
    Abstract: A process for curing low-k spin-on dielectric layers based on alkyl silsesquioxane polymers by laser scanning is described wherein curing is achieved by both photothermal and photochemical mechanisms. The layers are deposited by spin deposition, dried and cured by raster scanning with a pulsed laser at energies between 0.1 and 1 Joules/cm.sup.2. Because the laser causes heating of the layer, a nitrogen jet is applied in the wake of the scanning laser beam to rapidly cool the layer and to inhibit oxidation and moisture absorption. The laser induced heating also assists in the discharge of moisture and by-products of the polymerization process. The laser operates at wavelengths between 200 and 400 nm. Insulative layers such as silicon oxide are sufficiently transparent at these so that oxide segments overlying the polymer layer do not inhibit the curing process. Implementation of the laser scanning feature is readily incorporated into an existing spin-on deposition and curing tool.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: September 19, 2000
    Assignees: Chartered Semiconductor Manufacturing Ltd., National Univ. of Singapore, Nanyang Technology Univ.
    Inventors: Chee Tee Chua, Yuan-Ping Lee, Mei Sheng Zhou, Lap Chan
  • Patent number: 6009888
    Abstract: A method of stripping photoresist and polymer from a wafer after a dry etch of a nitrade or a polysilicon layer that immerses the wafer in a peroxydisulfate (S.sub.2 O.sub.8.sup.2-)/HCl wet bath and while the wafer is still immersed, irradiates the wafer with a UV laser. The method comprises: (a) forming an silicon nitride layer 24 and a photoresist pattern 28 over a semi conductor structure 10; (b) dry etching the silicon nitride layer 24 thus forming a polymer 30 over the photoresist pattern, and the silicon nitride layer, (c) Immersing the substrate, the photoresist pattern, the polymer 30 in a liquid bath 34 comprising (1) peroxydisulfate (S.sub.2 O.sub.8.sup.2-), (2) HCl, and (3) water; and irradiating the photoresist pattern 28 and polymer layer 30 with a UV laser thereby removing the photoresist 28 and polymer 30.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: January 4, 2000
    Assignee: Chartered Semiconductor Manufacturing Company, Ltd.
    Inventors: Jian-Hui Ye, Yuan-Ping Lee, Mei-Sheng Zhou, Yong-Feng Lu