Temperature coefficients of Hall sensors made of InSb/GaAs epitaxial layers

We discuss the impact of the temperature coefficients (TCs) of the Hall voltage χ, the resistance α, and the electron mobility λ on the output voltage TC of Hall sensors made of heavily donor doped epitaxial InSb/GaAs thin films. We point bout that in those n+-InSb epitaxial films, each of the TCs spans some range of magnitudes that include both negative and positive values. The concrete value of each of the TCs depends on the preparation technology and temperature range, however, the relationship γ = χ−α must hold. Thus, various combinations of the TCs can be realized, and some of them can minimize the output voltage TC in one of the feed regime: the constant driving current or the constant voltage regime. For example, λ is the TC that determines the output voltage TC in the driving voltage regime. We show that n+-InSb epitaxial films that have small λ in a broad temperature range can be obtained in special preparation conditions.