InAs/Al0.2Ga0.8Sb quantum well Hall effect sensors

Hall sensors with high sensitivity and excellent temperature stability were fabricated from quantum wells based on an InAs/Al0.2Ga0.8Sb heterostructure. The layers were grown on semi-insulating GaAs substrates by molecular beam epitaxy (MBE). Maximum Hall mobilities of 29.500 cm(2) V-1 s(-1) with sheet electron concentrations of 2 x 10(12) cm(-2) were measured at room temperature for an undoped quantum well structure. For a cross-shaped sensor, these excellent transport properties resulted in sensitivities of 0.9 T-1 (for voltage drive) and 300 V A(-1) T-1 (for current drive). Additional doping of the InAs quantum well leads to an improvement of the temperature stability of the input resistance and sensitivity in the temperature range of -100 degrees C to +150 degrees C. (C) 2000 Elsevier Science S.A. All rights reserved.