Patents by Inventor Michael T. Andreas

Michael T. Andreas 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: 5855811
    Abstract: A composition prepared from water, hydrofluoric acid (HF) and tetraalkylammonium hydroxide (TAAH, preferably tetramethylammonium hydroxide (TMAH)) or tetraalkylammonium fluoride and solvent with or without HF or TAAH is used to clean residue from a semiconductor wafer, where the residue is formed as a result of a planarization process, such as chemical mechanical polishing. Incorporation of TMAH into an aqueous HF composition retards the rate at which the composition dissolves borophosphosilicate (BPSG) without effecting the rate at which silica is dissolved. Thus, the aqueous HF/TMAH composition may be used to completely remove silica-containing residue from a BPSG surface, with a tolerable level of BPSG removal.
    Type: Grant
    Filed: October 3, 1996
    Date of Patent: January 5, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Eric K. Grieger, Michael T. Andreas, Michael A. Walker