Patents by Inventor Hua Younan

Hua Younan 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).

  • Method for etching a silicided poly using fluorine-based reactive ion etching and sodium hydroxide based solution immersion
    Patent number: 6689698
    Abstract: A method for removing a silicide poly on an integrated circuit (IC) chip. Specifically, one embodiment of the present invention discloses a method for exposing a gate oxide layer with a fluorine based reactive ion etching (F-based RIE) process and immersion in a sodium hydroxide based solution. The F-based RIE damages a silicide layer that covers a polysilicon gate layer. Damage to the silicide layer allows for penetration of chemicals to a polysilicon gate layer. Immersion of the IC chip in the sodium hydroxide based solution etches away the polysilicon gate layer and lifts off the silicide layer without altering an underlying gate oxide layer. Also, another embodiment uses a solution including sodium hydroxide and sodium chloride. As such, failure analysis of the gate oxide layer can proceed without concern for damage due to the removal process.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: February 10, 2004
    Assignee: Chartered Semiconductor Manufacturing Limited
    Inventors: Song Zhigang, Guo Zhi Rong, Shailesh Redkar, Hua Younan
  • Method for etching a silicided poly using fluorine-based reactive ion etching and sodium hydroxide based solution immersion
    Publication number: 20030092276
    Abstract: A method for removing a silicide poly on an integrated circuit (IC) chip. Specifically, one embodiment of the present invention discloses a method for exposing a gate oxide layer with a fluorine based reactive ion etching (F-based RIE) process and immersion in a sodium hydroxide based solution. The F-based RIE damages a silicide layer that covers a polysilicon gate layer. Damage to the silicide layer allows for penetration of chemicals to a polysilicon gate layer. Immersion of the IC chip in the sodium hydroxide based solution etches away the polysilicon gate layer and lifts off the silicide layer without altering an underlying gate oxide layer. Also, another embodiment uses a solution including sodium hydroxide and sodium chloride. As such, failure analysis of the gate oxide layer can proceed without concern for damage due to the removal process.
    Type: Application
    Filed: November 13, 2001
    Publication date: May 15, 2003
    Applicant: CHARTERED SEMICONDUCTORS MANUFACTURED LIMITED
    Inventors: Song Zhigang, Guo Zhi Rong, Shailesh Redkar, Hua Younan