Effect of the Passivation Layer on the Noise Characteristics of Mid-Wave-Infrared InAs/GaSb Superlattice Photodiodes

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Tansel T., Kutluer K., Salihoglu O., AYDINLI A., ASLAN B., Arikan B., ...More

IEEE PHOTONICS TECHNOLOGY LETTERS, vol.24, no.9, pp.790-792, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 9
  • Publication Date: 2012
  • Doi Number: 10.1109/lpt.2012.2188504
  • Journal Name: IEEE PHOTONICS TECHNOLOGY LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.790-792
  • Keywords: InAs/GaSb, mid-wave-infrared photodiode, noise characterization, passivation
  • Middle East Technical University Affiliated: Yes

Abstract

The authors describe the noise characterization of a mid-wavelength-infrared (MWIR) photodiode based on indium arsenide and gallium antimonide (InAs/GaSb) superlattice (SL), addressing the influence of different passivation layers applied to the surface of the device. The MWIR InAs/GaSb SL design structure is based on p-i-n configuration grown by the molecular beam epitaxy on a (001) n-GaSb substrate. The SiO2-passivated SL photodiodes demonstrated a Schottky-limited noise up to a bias voltage of -0.1 V where the measured peak responsivity is 1.37 A/W with a cut-off wavelength of 4.9 mu m and the specific detectivity as high as 1.23 x 10(12) cm. Hz(1/2)/W, demonstrating the high quality of the fabricated MWIR SL photodiodes. The noise measurements exhibited a frequency-dependent plateau (i.e., 1/f noise) for unpassivated and Si3N4-passivated samples, whereas 1/f-type noise suppression (i.e., frequency-independent plateau) with a noise current reduction at about 30 Hz of more than one order of magnitude was observed for the SiO2-passivated ones.