CHARACTERIZATION OF INGAAS INP MICROSCOPIC HALL PROBE ARRAYS WITH A 2DEG ACTIVE LAYER/

Highly-sensitive cryogenic microscopic Hall probe arrays based on an e pitaxial InGaAs/InP heterostructure with a two-dimensional electron ga s (2DEG) were prepared and characterised in high magnetic fields at 0. 3 K. A model of the heterostructure including a self-consistent descri ption of coupled Poisson and Schrodinger equations was solved to optim ise its design. Test arrays exhibit a constant 2DEG concentration at 4 .2-100 K, which gives a temperature coefficient lower than 100 ppm deg rees C-1. The magnetic sensitivity is greater than or equal to 1250 VA (-1)T(-1). Quantum oscillations in the 2DEG structure in high magnetic fields at temperatures below 4.2 K can be suppressed by increasing bi as current supplied to the arrays respecting their dimensions. Noise c haracteristics at 300 K are also presented. (C) 1998 Elsevier Science S.A. All rights reserved.