Patents by Inventor Dietrich Ristow

Dietrich Ristow 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: 5960269
    Abstract: In a method for manufacturing a field effect transistor, a semiconductor layer sequence is grown that has a channel layer (2), a barrier layer (3) and a highly doped InGaAs layer (6) suitable for low-impedance contacting to a metal contact. A passivation layer (8) of dielectric is applied and is structured for the region lying between source, gate and drain. An auxiliary layer (10) is applied by vapor-deposition in a very flat incident angle such that the gate region remains free. The semiconductor layers are etched out in the region of the gate down onto the barrier in a plurality of RIE etching processes. The auxiliary layer is removed, spacers are produced at the sidewalls of the passivation layer, a refractory metallization is deposited surface-wide and etched back in planarizing fashion, so that separate contacts for source, gate and drain derive. Finally, the terminal metallization is applied.
    Type: Grant
    Filed: August 6, 1997
    Date of Patent: September 28, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventors: Dietrich Ristow, Antonio Mesquida Kuesters
  • Patent number: 5298444
    Abstract: A method for manufacturing a field effect transistor which includes one more spacer provided in the gate recess adjacent the drain sidewall than adjacent the source sidewall in the contact such that a gate metallization is displaced asymmetrically toward a source side sidewall of the recess; and method for manufacturing same wherein oblique vapor deposition of an auxiliary layer into a recess for the gate region makes it possible for a spacer therein at the source side to be removed whereas a spacer of the drain side remains in place, such that the subsequent gate metallization is positioned closer to the source than to the drain.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: March 29, 1994
    Assignee: Siemens Aktiengesellschaft
    Inventor: Dietrich Ristow
  • Patent number: 4425573
    Abstract: A MESFET is disclosed wherein a gallium arsenide semiconductor material is doped. The doping magnitude differs in the source area, drain area, and in the gate area. An increase of the dielectric strength without an increase of parasitic resistances is provided. In the manufacture of the MESFET, shadowing techniques are employed to vary the doping magnitudes.
    Type: Grant
    Filed: November 25, 1981
    Date of Patent: January 10, 1984
    Assignee: Siemens Aktiengesellschaft
    Inventor: Dietrich Ristow
  • Patent number: 4389280
    Abstract: Very thin semiconductor chips are produced from a relatively large semiconductor substrate (such as gallium arsenide substrate) by generating a select pattern of crystallographic stress areas in a front surface of the substrate, as by mechanical scoring or application of a layer of material having a coefficient of thermal expansion significantly different from that of the semiconductor material in a pattern corresponding to the desired chip; applying an etch-resistant carrier member to such stressed front surface and etching the entire back surface of the substrate into a thickness less than 50 .mu.m, whereby the etching reaction penetrates into the region of the crystallographic stress and a division of the resultant eroded body into individual chips corresponding to the selected patterns occurs, with the chips being carried by said carrier member.
    Type: Grant
    Filed: November 27, 1981
    Date of Patent: June 21, 1983
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jan-Erik Mueller, Dietrich Ristow, Hermann Kniepkamp
  • Patent number: 4325747
    Abstract: A MESFET is disclosed wherein a gallium arsenide semiconductor material is doped. The doping magnitude differs in the source area, drain area, and in the gate area. An increase of the dielectric strength without an increase of parasitic resistances is provided. In the manufacture of the MESFET, shadowing techniques are employed to vary the doping magnitudes.
    Type: Grant
    Filed: May 14, 1979
    Date of Patent: April 20, 1982
    Assignee: Siemens Aktiengesellschaft
    Inventor: Dietrich Ristow
  • Patent number: 4292643
    Abstract: A planar Schottky diode is disclosed which is inserted into a transmission line without disruption of characteristic impedance. The diode comprises a plurality of parallel finger-like projections forming Schottky contacts distributed over a width of the transmission line and also of ohmic contacts surrounding these projections but with a longer contact edge.
    Type: Grant
    Filed: August 1, 1979
    Date of Patent: September 29, 1981
    Assignee: Siemens Aktiengesellschaft
    Inventors: Walter Kellner, Hermann Kniepkamp, Dietrich Ristow