We report on the performance of GaSb pn junction photodiodes fabricated using electron cyclotron resonance plasma etching using Cl-2 /Ar recipe, a mixed gas recipe consisting of Cl-2 /BCl3 /CH4 /Ar/H-2 and wet chemical etching. Diodes fabricated using Cl-2 /BCl3 /CH4 /Ar/H-2 recipe show an order of magnitude lower leakage current density and lower ideality factor. The highest value of the zero bias dynamic resistance-area product was obtained for Cl-2/BCl3/CH4 /Ar/H-2 etched diodes and was equal to 830 Omega cm(2) as compared to 300 Omegacm(2) for Cl-2 /Ar and 330 Omega cm(2) for wet etching. Spectral responsivity of Cl-2/BCl3/CH4/Ar/H-2 etched diodes was observed to be three times that of Cl-2/Ar and wet etched diodes. Overall, the diodes etched using the recently reported Cl-2/BCl3/CH4/Ar/H-2 recipe provided the best optical and electrical characteristics. (C) 2004 The Electrochemical Society.