Highly sensitive In/sub 0.53/Ga/sub 0.47/As/InP Hall sensors grown by MOVPE

Abstract

High performance InP/InGaAs Hall sensors appropriate for applications requiring high sensitivity at low power dissipation, good linearity, low temperature sensitivity, and high resolution are reported. The layer structures grown by MOVPE combine a high mobility In/sub 0.53/Ga/sub 0.47/As channel with isolation by semi-insulating InP. With this design bias current related sensitivities up to 760 V/AT at sheet resistances below 840 /spl Omega//square have been achieved, allowing high output signals at low power dissipation. Due to the active layer isolation by semi-insulating InP, bias currents are not limited by channel pinch-off or junction breakdown. This leads to absolute sensitivities as high as 12.5 V/T. Linearity errors are lower than /spl minus/0.8% up to magnetic fields of 0.5 T. Temperature coefficients of the sensitivity were measured for different donor concentrations of the active layer. The lowest value of /spl minus/0.07%/K was found for a doping of 10/sup 16/ cm/sup /spl minus/3/, in accordance with theoretical predictions. High signal-to-noise ratios corresponding to minimal detectable fields of 50 nT/Hz/sup l/2/ and 160 nT/Hz/sup l/2/, respectively, were measured at 1 kHz and 100 Hz.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>