Title :
Improvement of dark current using InP/InGaAsP transition layer in large-area InGaAs MSM photodetectors
Author :
Kim, Junghwan ; Johnson, William B. ; Kanakaraju, S. ; Calhoun, L.C. ; Lee, Chi H.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Maryland, College Park, MD, USA
fDate :
3/1/2004 12:00:00 AM
Abstract :
A large-area InGaAs metal-semiconductor-metal (MSM) photodetector with 1×1 mm2 photoactive area for free-space optical communication applications has been designed, fabricated, and characterized. Interdigitated electrodes of 2-μm widths and 15-μm spacings are designed to maximize the responsivity, and enable MSM photodetectors to reach a maximum responsivity at 1.53-μm wavelength. By employing a two-step InP/InGaAsP transition layer, the dark current density of 45 fA/μm2 was achieved at 10-V bias and at room temperature. Dark current-bias voltage curves were measured as a function of temperature from 40 to 270 K to estimate the activation energy. A 3-dB bandwidth of 210 MHz was obtained at a 10-V bias, and the measured result was compared with the designed bandwidth.
Keywords :
III-V semiconductors; dark conductivity; gallium arsenide; indium compounds; metal-semiconductor-metal structures; phosphorus compounds; photodetectors; 1.53 micron; 210 MHz; 293 to 298 K; 40 to 270 K; InP-InGaAsP; Schottky barriers; activation energy; current-bias voltage curve; dark current; epitaxial layers; free-space optical communication; interdigitated electrodes; large-area MSM photodetectors; metal-semiconductor-metal photodetector; photoactive area; transition layer; Bandwidth; Dark current; Electrodes; Indium gallium arsenide; Indium phosphide; Optical design; Optical fiber communication; Photodetectors; Temperature; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2003.822276
