HIGHLY SENSITIVE IN0.75GA0.25AS ALINAS HALL SENSORS/

High-performance InGaAs/InAlAs/InP Hall sensors with high magnetic sen sitivity, good linearity, low temperature coefficient and high resolut ion are reported. These sensors use the properties of a two-dimensiona l electron gas and the benefit of pseudomorphic material, in which bot h the alloy composition and the built-in strain offer additional degre es of freedom for band structure tailoring. With the described growth optimization of pseudomorphic In0.75Ga0.25As/Al0.52In0.48As heterostru ctures by molecular beam epitaxy, a high electron mobility of 13 000 c m(2) V-1 s(-1) at room temperature has been obtained. A physical model of the structure including a self-consistent description of the coupl ed Schrodinger and Poisson equations has been developed to better unde rstand the influence of the design of the heterostructure on its elect ronic properties. These results have been used in order to optimize th e structure design. A magnetic sensitivity of 580 V A(-1) T-1 with a t emperature coefficient of -550 ppm degrees C-1 between -80 degrees C a nd -85 degrees C has been obtained, and high signal-to-noise ratios co rresponding to minimal magnetic field of 350 nT Hz(-1/2) at 100 Hz and 120 nT Hz(-1/2) at 1 kHz have been measured.