Mechanical and piezoresistive properties of InAs/AlGaSb cantilevers

We fabricated piezoresistive micromechanical cantilevers using InAs/AlGaSb heterostructures grown by molecular beam epitaxy on GaAs (1 1 1) A and (0 0 1) substrates. The piezoresistance allows the cantilever displacement and mechanical resonance to be electrically detected. The cantilever fabricated on (0 0 1) substrate showed much smaller quality factors, indicating it has much larger energy dissipation than the one on (1 1 1) A. The measurement of the temperature dependence of the elastic constant suggests increased unharmonic lattice vibration for the (0 0 1) sample. These differences between (1 1 1) A and (0 0 1) samples could be induced by the high density of misfit dislocations formed in the (0 0 1) heterostructures.