Strained Quantum Well InAs Micro-Hall Sensors: Dependence of Device Performance on Channel Thickness

Magnetic sensitivity and low-frequency noise in micro-Hall sensors based on pseudomorphic InAs quantum well channels are investigated as functions of InAs thickness. The strained InAs quantum wells with thickness between 0 and 20 Aring are added into lattice-matched doped channel In_0.53Ga_0.47As/In_0.47Al_0.48As/InP heterostructures and enhance the absolute magnetic sensitivity by increasing the electron mobility. We show that the increase of the InAs channel thickness also leads to a significant reduction of the low-frequency noise. The result is an improved magnetic field detection over a broad frequency range. A minimum magnetic field detection limit of nT is resolved by a 40-m wide doped channel micro-Hall device at frequencies around kHz.