Patents by Inventor Leping Li

Leping Li 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: 5644221
    Abstract: A method and apparatus for endpoint detection in removal of a film from a semiconductor wafer is provided, with a sensor for creating a signal responsive to the film removal process, a positive feedback amplifier coupled to the sensor, the positive feedback amplifier having a mode selector, and an analyzer coupled to the positive feedback amplifier.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: July 1, 1997
    Assignee: International Business Machines Corporation
    Inventors: Leping Li, Steven George Barbee, Arnold Halperin
  • Patent number: 5616740
    Abstract: Process of making compounds having the formula ##STR1## wherein --OR.sup.1 comprises alkanoyl or the C-13 side-chain of taxol; R.sup.2, R.sup.3, and R.sup.6 can be oxygenated or hydrogen in various combinations; and R.sup.4 and R.sup.5 are acyl groups.
    Type: Grant
    Filed: May 11, 1995
    Date of Patent: April 1, 1997
    Assignee: Abbott Laboratories
    Inventors: Larry L. Klein, Clinton M. Yeung, Leping Li
  • Patent number: 5582746
    Abstract: A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process during etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; and recording a plurality of values of the electrical characteristic as a function of time during etching. From the plurality of recorded values and corresponding times, instantaneous etch rates, average etch rates, and etching end points may be determined. Such a method and the apparatus therefor are particularly useful in a wet chemical etch station.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: December 10, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Yiping Hsiao, Leping Li, Eugene H. Ratzlaff, Justin W. Wong
  • Patent number: 5573624
    Abstract: A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process during etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; detecting a minimum and maximum value of the electrical characteristic during etching; determining the times of the minimum and maximum values; and comparing the times of the minimum and maximum values to determine a film etching uniformity value. Such a method and the apparatus therefor are particularly useful in a wet chemical etch station, and are useful for film deposition process quality control.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: November 12, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Yiping Hsiao, Leping Li, Eugene H. Ratzlaff, Justin W. Wong
  • Patent number: 5573623
    Abstract: A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing at least two toroidal windings in the wet chemical etchant to be proximate to but not in contact with the workpiece; and monitoring an electrical characteristic between said at least two toroidal windings, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process. Such a method and apparatus are particularly useful in a wet chemical etch station.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: November 12, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Leping Li, Eugene H. Ratzlaff
  • Patent number: 5571822
    Abstract: A method of inhibiting tumor-cell growth in a mammalian subject, by administering a therapeutically effective amount of a selected 2-phenyl-4-quinolone compound. The selected compound shows unexpectely high activity against a variety of solid tumor cells.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: November 5, 1996
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Kuo-Hsiung Lee, Sheng-Chu Kuo, Tian-Shung Wu, Hui K. Wang, Leping Li
  • Patent number: 5559428
    Abstract: The change in thickness of a film on an underlying body such as a semiconductor substrate is monitored in situ by inducing a current in the film, and as the thickness of the film changes (either increase or decrease), the changes in the current are detected. With a conductive film, eddy currents are induced in the film by a generating an alternating electromagnetic field with a sensor which includes a capacitor and an inductor.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: September 24, 1996
    Assignee: International Business Machines Corporation
    Inventors: Leping Li, Steven G. Barbee, Arnold Halperin, Tony F. Heinz
  • Patent number: 5516399
    Abstract: A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process for the etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing at least two conductive electrodes in the wet chemical bath, wherein the at least two electrodes are proximate to but not in contact with the at least one wafer, and further wherein said two electrodes are positioned on the same side of the wafer; and monitoring an electrical characteristic between the at least two electrodes, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process. Such a method and apparatus are particularly useful in a wet chemical etch station.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: May 14, 1996
    Assignee: International Business Machines Corporation
    Inventors: Michael J. Balconi-Lamica, Steven G. Barbee, Tony F. Heinz, Yiping Hsiao, Leping Li, Eugene H. Ratzlaff, Justin Wai-chow Wong
  • Patent number: 5501766
    Abstract: A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process to minimize overetch of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; detecting a minimum and maximum value of the electrical characteristic during etching; determining the times of the minimum and maximum values; and comparing the times of the minimum and maximum values to determine an overetch value. The overetch value may be compared to a desired value to control the etching process.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: March 26, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Yiping Hsiao, Leping Li, Eugene H. Ratzlaff, Justin W. Wong
  • Patent number: 5500073
    Abstract: A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process during etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; and recording a plurality of values of the electrical characteristic as a function of time during etching. From the plurality of recorded values and corresponding times, instantaneous etch rates, average etch rates, and etching end points may be determined. Such a method and the apparatus therefor are particularly useful in a wet chemical etch station.
    Type: Grant
    Filed: May 8, 1995
    Date of Patent: March 19, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Yiping Hsiao, Leping Li, Eugene H. Ratzlaff, Justin W. Wong
  • Patent number: 5489361
    Abstract: A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process during etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing two conductive electrodes in the wet chemical bath, wherein the two electrodes are proximate to but not in contact with a wafer; monitoring an electrical characteristic between the two electrodes as a function of time in the etchant bath of the at least one wafer, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process; detecting a minimum and maximum value of the electrical characteristic during etching; determining the times of the minimum and maximum values; and comparing the times of the minimum and maximum values to determine a film etching uniformity value. Such a method and the apparatus therefor are particularly useful in a wet chemical etch station, and are useful for film deposition process quality control.
    Type: Grant
    Filed: December 13, 1994
    Date of Patent: February 6, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Yiping Hsiao, Leping Li, Eugene H. Ratzlaff, Justin W. Wong
  • Patent number: 5480511
    Abstract: A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing at least two toroidal windings in the wet chemical etchant to be proximate to but not in contact with the workpiece; and monitoring an electrical characteristic between said at least two toroidal windings, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process. Such a method and apparatus are particularly useful in a wet chemical etch station.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: January 2, 1996
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Leping Li, Eugene H. Ratzlaff
  • Patent number: 5456788
    Abstract: A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing a base member having a reference surface; releasably securing the workpiece to the base member; providing at least two sensors disposed on the base member to be proximate to but not in contact with the outer perimeter of the workpiece surface; and monitoring an electrical characteristic between said at least two sensors, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: October 10, 1995
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Madhav Datta, Tony F. Heinz, Leping Li, Eugene H. Ratzlaff, Ravindra V. Shenoy
  • Patent number: 5451289
    Abstract: A fixture for in-situ chemical etch monitoring of an etching process during etching of at least one wafer contained in a wafer carrier is disclosed. The fixture comprises a set of primary guide members for engaging and guiding a front portion of the wafer carrier. A set of rear guide members engages and guides a rear portion of the wafer carrier. A set of electrode arms is included for receiving a respective electrode and corresponding electrode wire thereon. A mounting plate establishes a prescribed spacing of the set of primary guide members with respect to the set of electrode arms. A means for self-locking the first wafer contained in the wafer boat is connected to the mounting plate and further positioned in a prescribed manner with respect to the set of primary guide members and the set of electrode arms.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: September 19, 1995
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Leping Li, Eugene H. Ratzlaff
  • Patent number: 5445705
    Abstract: A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing a base member having a reference surface; releasably securing the workpiece to the base member; providing at least two sensors disposed on the base member to be proximate to but not in contact with the outer perimeter of the workpiece surface; and monitoring an electrical characteristic between said at least two sensors, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: August 29, 1995
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Madhav Datta, Tony F. Heinz, Leping Li, Eugene H. Ratzlaff, Ravindra V. Shenoy
  • Patent number: 5440056
    Abstract: Compounds having the formula ##STR1## wherein --OR.sup.1 comprises alkanoyl or the C-13 side-chain of taxol; R.sup.2, R.sup.3, and R.sup.6 can be oxygenated or hydrogen in various combinations; and R.sup.4 and R.sup.5 are acyl groups,as well as a process for the preparation thereof, pharmaceutical compositions containing the above compounds, and a method for their use in inhibiting tumor growth.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: August 8, 1995
    Assignee: Abbott Laboratories
    Inventors: Larry L. Klein, Clinton M. Yeung, Leping Li
  • Patent number: 5392124
    Abstract: A method and apparatus for detecting an etching endpoint of a film on a substrate whereby a first excitation beam of light having a prescribed wavelength is provided, the first light beam substantially containing only a first harmonic component of light at that wavelength. The first light beam is directed at a prescribed incident angle to an interface between the film and the substrate, the first light beam being reflected off the interface to thereby provide a second light beam, the second light beam containing the first harmonic component of the first light beam and a generated second harmonic component. The generated second harmonic component is detected and a first output signal representative thereof is provided. A generated second harmonic component reference of the first light beam is produced and a second output signal representative of a generated second harmonic component reference is provided.
    Type: Grant
    Filed: December 17, 1993
    Date of Patent: February 21, 1995
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Ulrich Hofer, Leping Li, Victor J. Silvestri
  • Patent number: 5386121
    Abstract: A non-intrusive, in-situ monitoring technique and apparatus is used for evaluating the presence and extent of a critical contaminating or passivating layer on a transparent sample, prior to a subsequent process step. A multiple internal reflection apparatus and method without the need for aligning mirrors reduces the time to maximize the light intensity through the sample and to the detector and eliminates the intensity loss due to reflection from each mirror. The technique and apparatus can be used to monitor for a critical hydrogen passivation layer so that it is maintained on the silicon surface right up to the point at which the reactants are introduced for the deposition. The in-situ monitoring and process control technique uses Fourier Transform Infrared Spectroscopy with Multiple Internal Reflections (FTIRS-MIR) which looks at the Si--H bond vibration. Apparatus implementing the technique provides a means of insuring reproducibility in films through direct monitoring of the passivating layer.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: January 31, 1995
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Leping Li, Victor J. Silvestri
  • Patent number: 5381234
    Abstract: A method and apparatus for measuring with monolayer sensitivity in real-time the condition of a sample, includes a device for producing a modulated and collimated, p-polarized excitation light beam, a device for directing the p-polarized beam to a surface of the sample such that an angle of incidence of the p-polarized light beam with respect to the normal of the surface is at the Brewster angle, first and second reflecting devices between which the sample is positioned, a mechanism for adjusting a distance between the first and second reflecting devices to adjust a number of interactions of the p-polarized excitation light beam with the sample surfaces, and a detector for detecting the p-polarized light beam output intensity distribution with respect to frequency front the sample surfaces. The reflecting devices and the sample are adjustably maintained parallel to one another to thereby maintain the Brewster angle of the input excitation light beam with respect to the normal of the sample surface.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: January 10, 1995
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Richard J. Lebel, Leping Li, Victor J. Silvestri
  • Patent number: 5338390
    Abstract: A contactless method and apparatus for real-time in-situ monitoring of a chemical etching process for the etching of at least one wafer in a wet chemical etchant bath are disclosed. The method comprises the steps of providing at least two conductive electrodes in the wet chemical bath, said at least two electrodes being proximate to but not in contact with the at least one wafer; and monitoring an electrical characteristic between the at least two electrodes, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process. Such a method and apparatus are particularly useful in a wet chemical etch station.
    Type: Grant
    Filed: December 4, 1992
    Date of Patent: August 16, 1994
    Assignee: International Business Machines Corporation
    Inventors: Steven G. Barbee, Tony F. Heinz, Leping Li, Eugene H. Ratzlaff