Surface passivation of GaInAsSb photodiode with thioacetamide

Alain Salesse (1) , André Joullié (1) , P. Calas (1) , J. Niéto (2) , F. Chevrier (1) , Yvan Cuminal (1) , Gerald Ferblantier (1) , Philippe Christol (1, 3)

1 IES - Institut d’Electronique et des Systèmes
2 Instituto de Investigacion en Comunicacion Optica (IICO)
3 NANOMIR - Composants à Nanostructure pour le moyen infrarouge

AlGaAsSb/GaInAsSb heterojunction mesa photodiodes having 2.2µm cutoff wavelength, grown by MBE on (p) GaSb substrates, have been passivated using thioacetamide CH4CSNH2 and ammonium sulphide (NH4)2S. Superior characteristics were obtained from devices processed with thioacetamide in acid me-dium (pH = 2.4). At room temperature the surface leakage currents were suppressed, and the photodiodes showed R0A product as high as 15 Wcm2 and detectivity D*(2µm, 0V) ~ 1010 cm Hz1/2 W-1. A model ex-plaining improvement with thioacetamide is proposed.

Domaines: Optique / photonique

Alain Salesse, André Joullié, P. Calas, J. Niéto, F. Chevrier, et al.. Surface passivation of GaInAsSb photodiode with thioacetamide. WILEY-VCH Verlag GmbH & Co. KGaA, Jan 2007, Wenheim, France. 4 p. ⟨hal-00103719⟩