Patents by Inventor Wilfried Ammon

Wilfried Ammon 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).

  • Publication number: 20060292890
    Abstract: A method for the production of a silicon single crystal by pulling the single crystal, according to the Czochralski method, from a melt which is held in a rotating crucible, the single crystal growing at a growth front, heat being deliberately supplied to the center of the growth front by a heat flux directed at the growth front. The method produces a silicon single crystal with an oxygen content of from 4*1017 cm?3 to 7.2*1017 cm?3 and a radial concentration change for boron or phosphorus of less than 5%, which has no agglomerated self-point defects. Semiconductor wafers are separated from the single crystal. These semiconductor wafers have may have agglomerated vacancy defects (COPs) as the only self-point defect type or may have certain other defect distributions.
    Type: Application
    Filed: August 31, 2006
    Publication date: December 28, 2006
    Applicant: Siltronic AG
    Inventors: Wilfried Ammon, Janis Virbulis, Martin Weber, Thomas Wetzel, Herbert Schmidt
  • Publication number: 20060283374
    Abstract: In a process for producing silicon semiconductor wafers, a silicon single crystal is pulled using the Czochralski method and is processed to form semiconductor wafers, a ratio V/G of pulling rate V and axial temperature gradient G at a growth front during the pulling of the single crystal being controlled in such a manner that agglomerated vacancy defects above a critical size are formed in the single crystal, the agglomerated vacancy defects, in a region of the semiconductor wafer that is of relevance to electronic components, shrinking during production of the components such that the size in this region no longer exceeds the critical size. Silicon semiconductor wafers with agglomerated vacancy defects in the relevant device region preferably contain agglomerated vacancy defects having an inner surface which is at least partially free of an oxide layer and a size of less than 50 nm.
    Type: Application
    Filed: June 14, 2006
    Publication date: December 21, 2006
    Applicant: Siltronic AG
    Inventors: Wilfried Ammon, Walter Haeckl, Andreas Huber, Ulrich Lambert
  • Publication number: 20050139961
    Abstract: Hetero-semiconductor structures possessing an SOI structure containing a silicon-germanium mixed crystal are produced at a low cost and high productivity. The semiconductor substrates comprise a first layer formed of silicon having germanium added thereto, a second layer formed of an oxide and adjoined to the first layer, and a third layer derived from the same source as the first layer, but having an enriched content of germanium as a result of thermal oxidation and thinning of the third layer.
    Type: Application
    Filed: December 15, 2004
    Publication date: June 30, 2005
    Applicant: Siltronic AG
    Inventors: Josef Brunner, Hiroyuki Deai, Atsushi Ikari, Martin Grassl, Atsuki Matsumura, Wilfried Ammon
  • Publication number: 20050032376
    Abstract: A process for producing a single-crystal silicon wafer, comprises the following steps: producing a layer on the front surface of the silicon wafer by epitaxial deposition or production of a layer whose electrical resistance differs from the electrical resistance of the remainder of the silicon wafer on the front surface of the silicon wafer, or production of an external getter layer on the back surface of the silicon wafer, and heat treating the silicon wafer at a temperature which is selected to be such that an inequality (1) [ O ? ? ? i ] < [ O ? ? ? i ] eq ? ( T ) ? exp ? ? ? 2 ? ? SiO ? 2 ? ? r ? ? ? k ? ? ? T is satisfied, where [Oi] is an oxygen concentration in the silicon wafer, [Oi]eq(T) is a limit solubility of oxygen in silicon at a temperature T, ?SiO2 is the surface energy of silicon dioxide, ? is a volume of a precipitated oxygen atom, r is a mean COP radius and k the Boltzmann constant, with the silicon wafer, during the heat treatment, at least part
    Type: Application
    Filed: July 16, 2004
    Publication date: February 10, 2005
    Inventors: Christoph Seuring, Robert Holzl, Reinhold Wahlich, Wilfried Ammon