Improvement of CO Sensitivity in GaN-Based Gas Sensors

Eunjung CHO  Dimitris PAVLIDIS  Guangyuan ZHAO  Seth M. HUBBARD  Johannes SCHWANK  

IEICE TRANSACTIONS on Electronics   Vol.E89-C   No.7   pp.1047-1051
Publication Date: 2006/07/01
Online ISSN: 1745-1353
DOI: 10.1093/ietele/e89-c.7.1047
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Heterostructure Microelectronics with TWHM2005)
Category: GaN-Based Devices
GaN,  gas sensor,  Pt Schottky diode,  CO,  

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Pt Schottky diode gas sensors for carbon monoxide (CO) were fabricated using slightly Si doped bulk GaN grown on sapphire substrate. The influence of diode size, Pt thickness, operating temperature on gas sensitivity was investigated. CO sensitivity was improved six times by optimizing the size and thickness of the Pt contact. Surface restructuring and morphology changes of Pt film were observed after thermal annealing. These changes are enhanced as the film thickness is reduced further and contribute to improve CO sensitivity.