April R Brown

US Patent:

7868354, Jan 11, 2011

Filed:

Nov 8, 2007

Appl. No.:

11/937375

Inventors:

Michael A. Garcia - Durham NC, US
Scott D. Wolter - Durham NC, US
April S. Brown - Durham NC, US
Joseph Bonaventura - Durham NC, US
Thomas F. Kuech - Madison WI, US

Assignee:

Duke University - Durham NC

International Classification:

H01L 31/119

US Classification:

257192, 257253, 257414, 257258, 257E31089

Abstract:

GaN-based heterojunction field effect transistor (HFET) sensors are provided with engineered, functional surfaces that act as pseudo-gates, modifying the drain current upon analyte capture. In some embodiments, devices for sensing nitric oxide (NO) species in a NO-containing fluid are provided which comprise a semiconductor structure that includes a pair of separated GaN layers and an AlGaN layer interposed between and in contact with the GaN layers. Source and drain contact regions are formed on one of the GaN layers, and an exposed GaN gate region is formed between the source and drain contact regions for contact with the NO-containing fluid. The semiconductor structure most preferably is formed on a suitable substrate (e. g. , SiC). An insulating layer may be provided so as to cover the semiconductor structure. The insulating layer will have a window formed therein so as to maintain exposure of the GaN gate region and thereby allow the gate region to contact the NO-containing fluid.

US Patent:

8471294, Jun 25, 2013

Filed:

Nov 18, 2010

Appl. No.:

12/948946

Inventors:

Michael A. Garcia - Durham NC, US
Scott D. Wolter - Durham NC, US
April S. Brown - Durham NC, US
Joseph Bonaventura - Durham NC, US
Thomas F. Kuech - Madison WI, US

Assignee:

Duke University - Durham NC

International Classification:

H01L 29/66

US Classification:

257192, 257253, 257E29216, 438116

Abstract:

GaN-based heterojunction field effect transistor (HFET) sensors are provided with engineered, functional surfaces that act as pseudo-gates, modifying the drain current upon analyte capture. In some embodiments, devices for sensing nitric oxide (NO) species in a NO-containing fluid are provided which comprise a semiconductor structure that includes a pair of separated GaN layers and an AlGaN layer interposed between and in contact with the GaN layers. Source and drain contact regions are formed on one of the GaN layers, and an exposed GaN gate region is formed between the source and drain contact regions for contact with the NO-containing fluid. The semiconductor structure most preferably is formed on a suitable substrate (e. g. , SiC). An insulating layer may be provided so as to cover the semiconductor structure. The insulating layer will have a window formed therein so as to maintain exposure of the GaN gate region and thereby allow the gate region to contact the NO-containing fluid.

US Patent:

20110199102, Aug 18, 2011

Filed:

Jun 16, 2009

Appl. No.:

12/999262

Inventors:

Michael A. Garcia - Durham NC, US
Scott D. Wolter - Durham NC, US
April S. Brown - Durham NC, US
William V. Lampert - Durham NC, US

International Classification:

G01R 27/26
B01L 99/00
G01R 27/08
G01R 19/00

US Classification:

324658, 422 69, 324691, 324 7611

Abstract:

A van der Pauw (VDP) sensor comprising an electronic circuit electrically coupled to a surface, the surface comprising a type III-V material, and the electronic circuit measuring a sheet resistivity of the surface using a VDP technique. The VDP sensor may further comprise a macromolecule, such as a porphyrin, an oligonucleotide, a protein, a polymer or a combination thereof in contact with the surface. The VDP sensors may be arranged in an array of similar or different sensors. An electronic circuit electrically coupled to a type III-V material having a two-dimensional electron gas, such as InAs or InN, the electronic circuit measuring an electrical property of the type III-V material having a two-dimensional electron gas.