Patents by Inventor Ioulia P. Smorchkova

Ioulia P. Smorchkova 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).

  • Group-III nitride based high electron mobility transistor (HEMT) with barrier/spacer layer
    Patent number: 6849882
    Abstract: A Group III nitride based high electron mobility transistors (HEMT) is disclosed that provides improved high frequency performance. One embodiment of the HEMT comprises a GaN buffer layer, with an AlyGa1?yN (y=1 or y 1) layer on the GaN buffer layer. An AlxGa1?xN (0?x?0.5) barrier layer on to the AlyGa1?yN layer, opposite the GaN buffer layer, AlyGa1?yN layer having a higher Al concentration than that of the AlxGa1?xN barrier layer. A preferred AlyGa1?yN layer has y=1 or y˜1 and a preferred AlxGa1?xN barrier layer has 0?x?0.5. A 2DEG forms at the interface between the GaN buffer layer and the AlyGa1?yN layer. Respective source, drain and gate contacts are formed on the AlxGa1?xN barrier layer. The HEMT can also comprising a substrate adjacent to the buffer layer, opposite the AlyGa1?yN layer and a nucleation layer between the AlxGa1?xN buffer layer and the substrate.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: February 1, 2005
    Assignee: Cree Inc.
    Inventors: Prashant Chavarkar, Ioulia P. Smorchkova, Stacia Keller, Umesh Mishra, Wladyslaw Walukiewicz, Yifeng Wu
  • Group-III nitride based high electron mobility transistor (HEMT) with barrier/spacer layer
    Publication number: 20020167023
    Abstract: A Group III nitride based high electron mobility transistors (HEMT) is disclosed that provides improved high frequency performance. One embodiment of the HEMT comprises a GaN buffer layer, with an AlyGa1−yN (y=1 or y 1) layer on the GaN buffer layer. An AlxGa1−xN (0≦x≦0.5) barrier layer on to the AlyGa1−yN layer, opposite the GaN buffer layer, AlyGa1−yN layer having a higher Al concentration than that of the AlxGa1−xN barrier layer. A preferred AlyGa1−yN layer has y=1 or y≃1 and a preferred AlxGa1−xN barrier layer has 0≦x≦0.5. A 2DEG forms at the interface between the GaN buffer layer and the AlyGa1−yN layer. Respective source, drain and gate contacts are formed on the AlxGa1−xN barrier layer. The HEMT can also comprising a substrate adjacent to the buffer layer, opposite the AlyGa1−yN layer and a nucleation layer between the AlxGa1−xN buffer layer and the substrate.
    Type: Application
    Filed: March 19, 2002
    Publication date: November 14, 2002
    Applicant: CREE LIGHTING COMPANY and REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Prashant Chavarkar, Ioulia P. Smorchkova, Stacia Keller, Umesh Mishra, Wladyslaw Walukiewicz, Yifeng Wu