Patents by Inventor Chuan H. Liu

Chuan H. Liu 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: 6269315
    Abstract: A method for testing the reliability of a dielectric thin film. An exponential current ramp test is performed with a delay time to test the dielectric thin film. An exponential current ramp charge-to-breakdown distribution, which is represented by cumulative distribution failure percentage, is obtained. An exponential current ramp charge-to-breakdown at a cumulative distribution failure percentage is calculated. An exponential current ramp constant and a constant current stress constant at the cumulative distribution failure percentage are calculated. A constant current stress charge-to-breakdown at the cumulative distribution failure percentage is calculated by using a specified current density and the constant current stress constant at the cumulative distribution failure percentage. The constant current stress charge-to-breakdown at the cumulative distribution failure percentage is compared to a specified constant current stress charge-to-breakdown to determine the reliability of the dielectric thin film.
    Type: Grant
    Filed: January 14, 1999
    Date of Patent: July 31, 2001
    Assignee: United Microelectronics Corp.
    Inventors: Kuan-Yu Fu, Chuan H. Liu, Donald Cheng, Sheng-Hsing Yang, Mu-Chun Wang
  • Patent number: 6268269
    Abstract: A fabrication method for an oxide layer with reduced interface-trapped charges, which is applicable to the fabrication of a gate oxide layer of a flash memory device, is described. The method includes conducting a first inert ambient annealing process, followed by growing an oxide layer on the silicon substrate. A second inert ambient annealing process is then conducted on the oxide layer. Carbon ions are then incorporated into the interface between the oxide layer and the silicon substrate, followed by a third ambient annealing process.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: July 31, 2001
    Assignee: United Microelectronics Corp.
    Inventors: Ming-Tsan Lee, Chuan H. Liu, Kuan-Yu Fu
  • Patent number: 6249139
    Abstract: A method is described for taking a lifetime measurement of an ultra-thin dielectric layer. In order to discover the life time of the ultra-thin dielectric layer, the measurement comprises using about one half of a stress voltage to measure a time-dependent leakage current of the ultra-thin dielectric layer.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: June 19, 2001
    Assignees: United Microelectronics Corp., United Semiconductor Corp.
    Inventors: Kuan-Yu Fu, Mainn-Gwo Chen, Chuan H. Liu
  • Patent number: 6169035
    Abstract: A LOCOS method uses a reagent mixed of etchant and oxidizer to simultaneously perform the step of forming the FOX layer and the step of removing a mask layer of the conventional LOCOS method. The applied temperature is about 950-1150° C. The etchant. such as a HF acid solution, is used to remove the mask layer, and the oxidizer, such as O2, is used to form the FOX layer on a silicon substrate.
    Type: Grant
    Filed: October 14, 1998
    Date of Patent: January 2, 2001
    Assignee: United Microelectronic Corp.
    Inventors: Chuan H. Liu, Chin-Kun Lo, Mainn-Gwo Chen
  • Patent number: 6072677
    Abstract: An electrostatic discharge protective circuit formed by use of a silicon controller rectifier is coupled to an input port and an internal circuit for discharging electrostatic charges on the input port to ground. When the electrostatic charges are applied on the input port, a punch-through effect is created between a first P-type diffusion region and a second N-type diffusion region to turn on a parasitic NPN bipolar junction transistor. At the same time, a voltage is applied on a gate of the MOS transistor via a small-signal equivalent capacitor to turn on itself, thereby discharging the electrostatic charges. Accordingly, the trigger voltage of the silicon controller rectifier can be efficiently lowered to improve the electrostatic discharge protective capability of the silicon control rectifier.
    Type: Grant
    Filed: November 3, 1998
    Date of Patent: June 6, 2000
    Assignee: United Microelectronics Corp.
    Inventors: Mainn-Gwo Chen, Ming-Jer Chen, Chuan H. Liu