Patents by Inventor Willi Walter

Willi Walter 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).

  • Process for the selective growth of GaAs
    Patent number: 5185289
    Abstract: The process is particularly useful in the fabrication of GaAs quantum well (QW) laser diodes. Starting point is a ridge-patterned (100)-substrate (21), the crystal orientation of the sidewalls, e.g., (411A)-oriented, being different from that of the horizontal top. The sidewall facets thus have a lower Ga incorporation rate.In a molecular beam epitaxy (MBE) system, the lower AlGaAs cladding layer (22) is first grown, followed by the high-temperature growth of the active GaAs QW (23). Due to diffusion and desorption processes, the GaAs thickness at the sidewalls is smaller than on the horizontal top of the ridge. During a short growth interrupt, the GaAs completely desorbs from the sidewall facets. With the subsequent growth of the upper cladding layer (24), the QW becomes laterally embedded in higher bandgap material providing for lateral electric confinement.
    Type: Grant
    Filed: June 25, 1991
    Date of Patent: February 9, 1993
    Assignee: International Business Machines Corporation
    Inventors: Heinz P. Meier, Edward A. Van Gieson, Willi Walter