A Ge-on-Si single photon avalanche diode operating in Geiger mode at Infrared wavelengths

Mahdi Aminian, Amir Sammak, Lin Qi, Lis K. Nanver, Edoardo Charbon

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

5 Citations (Scopus)
78 Downloads (Pure)


The Ge APD detectors are fabricated on Si by using a selective chemical-vapor deposition (CVD) epitaxial growth technique. A novel processing procedure was developed for the p+ Ge surface doping by a sequence of pure-Ga and pure-B depositions (PureGaB). Then, PVD Al is used to contact the n-type Si and the anode of p+n Ge diode. Arrays of diodes with different areas, as large as 40×40 μm2, were fabricated. The resulting p+n diodes have exceptionally good IV characteristics with ideality factor of ~1.1 and low saturation currents. The devices can be fabricated with a range of breakdown voltages from a minimum of 9 V to a maximum of 13 V. They can be operated both in proportional and in Geiger mode, and exhibit relatively low dark counts, as low as 10 kHz at 1 V excess reverse bias. The dark current at 1 V reverse bias are as low as 2 pA and 20 pA for a 2×2 μm2 and 2×20 μm2 devices, respectively. Higher IR-induced current than that induced by visible light confirms the sensitivity of Ge photodiodes at room temperature. The 25% peak in Id/Iref at an IR-wavelength of 1100 nm in Geiger mode is measured for excess bias voltages of 3 V and 4 V, where Id refers to the photocurrent of the 2×20 μm2 device at different wavelengths, and Iref is the reference photodiode current. The timing response (Jitter) for the APD when exposed to a pulsed laser at 637 nm and 1 V excess bias is measured as 900 ps at full width of half maximum (FWHM).

Original languageEnglish
Title of host publicationAdvanced Photon Counting Techniques VI
Publication statusPublished - 1 Dec 2012
Externally publishedYes
EventSPIE Defense, Security, and Sensing 2012 - Baltimore, United States
Duration: 25 Apr 201226 Apr 2012

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceSPIE Defense, Security, and Sensing 2012
Country/TerritoryUnited States


  • Ge-on-Si
  • Geiger mode
  • Infrared
  • PureGaB
  • Single-Photon Avalanche Diode
  • SPAD


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