Molecular beam epitaxy and characterization of InAs/Al0.2Ga0.8Sb heterostructures for magnetic sensing applications

InAs/Al0.2Ga0.8Sb quantum well structures of high quality were grown by molecular beam epitaxy. The structural and electrical quality was characterized by x-ray diffractometry, Raman spectroscopy and Hall transport measurements. When an optimized buffer layer was used on a GaAs substrate, electron mobilities of 28 000 cm(2) V-1 s(-1) at 300 K and 400 000 cm(2) V-1 s(-1) at 20 K were routinely achieved for undoped structures. These excellent transport properties were utilized in a sensitive magnetoresistive sensor.