A Pd/Pt/Au ohmic contact to AlSb/InAs0.7Sb0.3 heterostructures has been studied. The contacts provide a contact resistance of 0.07 (+/- 0.01) Omega mm when annealed at 300 degrees C for 15 min. Prior to annealing, the contact reacts non-uniformly with the heterostructure, but not down to the InAs0.7Sb0.3 channel. Following annealing at 300 degrees C for 15 min, the entire heterostructure beneath the contact is consumed down to the underlying AlSb buffer layer. This morphology differs from that reported for optimized ohmic contacts to AlGaAs/GaAs hetero structures. (c) 2006 Elsevier Ltd. All rights reserved.