Patents by Inventor Hans Fronius

Hans Fronius 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 of preparing semiconductor substrates
    Patent number: 4732648
    Abstract: A new method for GaAs substrate preparation which significantly reduces the ormation of oval defects during MBE growth of selectively doped n-Al.sub.x Ga.sub.1-x As/GaAs heterostructures. The method simply requires treatment in H.sub.2 SO.sub.4 after mechano-chemical polishing in NaOCl solution and generation of a protective surface oxide during in soldering. Routinely a density of oval defects of less than 200 cm.sup.-2 is achieved for 2-.mu.m thick heterostructures. The efficiency of the new preparation procedure is demonstrated by 2DEG mobilities in excess of 10.sup.6 cm.sup.2 /Vs at 6K obtained with a spacer width as narrow as 18 nm.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: March 22, 1988
    Assignee: Max Planck Gesellschaft zur Foerderung der Wissenschaften e.V.
    Inventors: Hans Fronius, Albrecht Fischer, Klaus Ploog