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The p-i-n photo detectors for UVA and UVB regions made of GaN/AlGaN
|Lech Dobrzanski , Dariusz Lenkiewicz , Krzysztof Góra , Andrzej Kozłowski , Andrzej Jagoda , Krystyna Przyborowska , Beata Stańczyk , Urszula Bielińska , Artur Wnuk|
Institute of Electronic Materials Technology (ITME), Wólczyńska 133, Warszawa 01-919, Poland
In this contribution we report on fabrication and testing of front side and backside illuminated UV p-i-n detectors. Short description of epitaxial structure, layout construction and device processing will be introduced followed by device characterization. Detector design trade offs will be discussed focused on differences between front side and backside-illuminated devices. The former exhibit uneven spectral response due to shallow light absorption in the p-type region and subsequent diffusive transport of generated carriers towards intrinsic region of device. For these reasons this devices are sensitive to the p-doping process deviations. In contrast device illuminated from the sapphire substrate side are immune towards p-region doping problems and have better responsivities, which values are as high as 0.15-0.20A/W. Spectral response of these diodes is even and resembles characteristics of a good band pass filter. We achieved this feature using "window" layers made of AlGaN in the vicinity of sapphire interface. Sensitivity of our devices has been estimated on basis of low frequency noise measurements. It appeared that its value is higher than 2 1012 cm Hz½ W-1.
Presentation: oral at E-MRS Fall Meeting 2004, Symposium C, by Lech Dobrzanski
See On-line Journal of E-MRS Fall Meeting 2004
Submitted: 2004-05-05 14:27 Revised: 2009-06-08 12:55