Title :
Responsivity and impact ionization coefficients of Si1-xGex photodiodes
Author :
Lee, Jinju ; Gutierrez-Aitken, Augusto L. ; Li, S.H. ; Bhattacharya, Pallab K.
Author_Institution :
Solid State Electron. Lab., Michigan Univ., Ann Arbor, MI, USA
fDate :
6/1/1996 12:00:00 AM
Abstract :
The spectral response and impact ionization coefficient ratio of Si1-xGex have been determined. Measurements were made on p+-i-n+ diodes grown by solid/gas source molecular beam epitaxy. The diodes are characterized by reverse breakdown voltages of 4-12 V and dark currents of 20-170 pA/μm2 . The long wavelength cut-off of the diodes increases from 1.2 μm to 1.6 μm as x increases from 0.08 to 1.0 with a maximum responsivity of 0.5 A/W in all the diodes tested. The ratio α/β varies from 3.3 to 0.3 in the same composition range, with α/β=1 at x≅0.45. These results have important implications in the use of this material system in various photodetection applications
Keywords :
Ge-Si alloys; avalanche breakdown; chemical beam epitaxial growth; impact ionisation; infrared detectors; molecular beam epitaxial growth; p-i-n photodiodes; photodetectors; semiconductor materials; 1.6 micron; 4 to 12 V; GSMBE; IR detectors; Si1-xGex photodiodes; SiGe; dark currents; impact ionization coefficients; long wavelength cutoff; molecular beam epitaxy; p+-i-n+ diodes; photodetection applications; responsivity; reverse breakdown voltages; solid/gas source MBE; spectral response; Dark current; Epitaxial growth; Impact ionization; Optical fiber communication; Optical noise; Photodetectors; Photodiodes; Photonic band gap; Semiconductor diodes; Silicon alloys;
Journal_Title :
Electron Devices, IEEE Transactions on
