Patents by Inventor Johnny C. Chen

Johnny C. Chen 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: 5263000
    Abstract: A drain power supply for generating and supplying a regulated positive potential to drain regions of selected memory cells via bit lines in an array of flash EEPROM memory cells during programming includes charge pump means (20) formed of a plurality of charge pump sections (20a-20h) driven by one of a plurality of staggered clock signals for generating a moderately high level positive voltage. Cancellation means (26, 28) are coupled to each of the plurality of charge pump sections for effectively canceling out threshold voltage drops in the charge pump circuit. A regulator circuit (22) responsive to the regulated positive potential at an output node and a reference voltage is provided for generating a control voltage so as to control the high level positive voltage on the output node.
    Type: Grant
    Filed: October 22, 1992
    Date of Patent: November 16, 1993
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Michael A. Van Buskirk, Johnny C. Chen, Chung K. Chang, Lee E. Cleveland, Antonio Montalvo
  • Patent number: 5087332
    Abstract: A process for making thin film magnetic heads includes forming a precisely defined back gap opening used for magnetic closure of the P1 and P1 pole pieces. A mushroom-like photoresist structure having a cap layer supported by a stem layer is formed over the P1 pole piece by a double resist spin and double exposure method with a critical baking step to harden previously deposited photoresist layers between the first exposure and the second photoresist spin. The cap layer defines the back gap opening. When the mushroom-like photoresist structure is removed by a single step lift-off with a solvent, the back gap opening is formed.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: February 11, 1992
    Assignee: Read-Rite Corp.
    Inventor: Johnny C. Chen