In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 44, No. 4S ( 2005-04-01), p. 2553-
Abstract:
We report the growth, fabrication and characterization of an Al x Ga 1-x N heteroepitaxial back-illuminated UV photodetector used for flip-chip mounting. This device is grown on a one-side-polished sapphire substrate with a low-temperature AlN buffer layer by 6-pocket multi-wafer metalorganic chemical vapor deposition (MOCVD) using a vertical reactor. In order to attain the UV region, we increased the Al mole fraction in the Al x Ga 1-x N epilayer and acquired an Al x Ga 1-x N epilayer that shows a crack-free surface morphology when the Al mole fraction was 30%. This device consists of a 1.2-µm-thick Al 0.3 Ga 0.7 N “window layer”, 0.16-µm-thick Al 0.08 Ga 0.92 N i-layer, 0.46-µm-thick Al 0.08 Ga 0.92 N p-layer, 0.1-µm-thick GaN p-layer and a 30-nm-thick GaN:Mg p + -contact layer. All device processes were completed by standard semiconductor processing techniques that include photolithography, metallization and etching. In this device, the zero-bias peak responsivity is measured to be about 0.1 A/W at 350 nm, which corresponds to an external quantum efficiency of 36%. The rise-and-fall time of the photoresponse is 4.1 ns. This device exhibits a low dark current density of 31.9 pA/cm 2 at zero bias. Therefore, we can successfully obtain the back-illuminated UV photodetector with good responsivity, fast photoresponse time and low dark current.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.44.2553
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2005
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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