Sulphur passivation of InAs(Sb)

• Published in: Applied surface science Vol. 113; pp. 388 - 392
• Main Authors: Gong, X.Y., Yamaguchi, T., Kan, H., Makino, T., Ohshimo, K., Aoyama, M., Kumagawa, M., Rowell, N.L., Rinfret, R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1997
• Subjects: Dangling bonds; Dark current; InAsSb; Photoluminescence; Spectroellipsometry; Sulphur passivation; Dangling bonds; 68.35-P; 07.60.Fs; Sulphur passivation; Photoluminescence; Spectroellipsometry; Dark current; InAsSb; 81.40.Tv; 85.60.Gz
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(96)00936-1

The sulphur passivation for the InAs surface was studied by photoluminescence (PL) and spectroscopic ellipsometry (SE). Effects of the treatment are compared with
I-
V characteristics and photoresponse (PR) of MESA structure devices fabricated with LPE multilayer of InAs
1−
y
(Sb
y
). It is expected that the dangling bonds at the surface are terminated in the forms of SIn, SSb bonds by the passivation, which results in a remarkable decrease of surface recombination center density. This phenomenon was confirmed by observing increases of PL intensity and of the PR of photodiodes. Four order reductions of dark current and remarkable increase of PR have been observed on sulphur passivated photodetectors. Stability of the effect of the sulphur passivation was also examined by SE as well as PR measurements. SE measurements showed that dielectric function of the surface layer for the InAs wafer has no absorption in the measured spectral range between 1.5 and 5.5 eV. After sulphur passivation, optical absorption appeared due to submonolayer sulphur atoms in good agreement with the results obtained from the InAs(Sb) photodetectors.