| US 7,394,112 B2 | ||
| Heterostructure with rear-face donor doping | ||
| Erhard Kohn, Ulm-Lehr (Germany); Ingo Daumiller, Isny (Germany); Markus Kamp, Kamp-Lintfort (Germany); and Matthias Seyboth, Beirnerstetten (Germany) | ||
| Assigned to MicroGaN GmbH, Ulm (Germany) | ||
| Filed on Jan. 03, 2006, as Appl. No. 11/324,601. | ||
| Application 11/324601 is a continuation of application No. 10/297234, filed on Feb. 12, 2003, granted, now 7,352,008. | ||
| Prior Publication US 2006/0113564 A1, Jun. 01, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. H01L 3/0328 (2006.01) | ||
| U.S. Cl. 257—192 [257/94; 257/280; 257/E33.005; 257/E33.068] | 23 Claims |
| 1. A field effect transistor comprising:
a heterostructure including a buffer layer or substrate;
a channel arranged on the buffer layer or on the substrate;
a capping layer arranged on the channel wherein the channel consists of a piezopolar material with piezoelectric polarization
having two different type piezocharges including piezoinduced positive charges and piezoinduced negative charges; and wherein
either the region around the boundary interface between the buffer layer or substrate and channel or the region around the
boundary interface between the channel and capping layer, but not both regions, is doped in a manner such that only one type
of the piezocharges occurring at the respective boundary interface is compensated; and
two contact electrodes and a gate electrode arranged on that surface of the capping layer distant to the channel.
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