Characterization of GaAs/AlGaAs heterostructure quantum wells by microwave absorption

Magnetic-field-dependent microwave absorption is shown to be a useful non-destructive and contact-free technique to study transport behavior in GaAs/AlGaAs devices. It allows quick measurement of resistance, mobility and carrier concentration in the two-dimensional electron gas of heterostructure quantum wells. The two and three dimensional conductivities may be separately evaluated allowing detailed study of conduction in the active layer of high electron mobility (HEMT) devices. Applications of the approach to examination of device structural dependencies, carrier-density conduction behavior and the effects of etch processing on quantum well integrity are presented.