Optimizing the physical contribution to the sensitivity and signal to noise ratio of extraordinary magnetoresistance quantum well structures

Abstract

For applications to extraordinary magnetoresistance (EMR) quantum well sensor design, the electron areal density n2D, the mobility μ, and the products n3D1∕2μ2 and n3D1∕2μ5∕2 are key physical parameters to be optimized for enhanced device sensitivity and signal to noise ratio. We model the electron areal density and carrier mobility in a two-dimensional electron gas layer developed in a δ-doped AlInSb∕InSb heterostructure. The nonparabolic band structure due to the nature of the small energy band gap of InSb is accounted for. The detailed description of the energy dispersion and the energy dependent effective mass are obtained by the k∙P method of band structure calculation. The transport properties are calculated by including contributions of scattering from ionized impurities, the background neutral impurities, the deformation potential acoustic phonons, and the polar optical phonons. We calculate the dependencies of n2D, μ, n3D1∕2μ2, and n3D1∕2μ5∕2 on temperature, spacer layer thickness, doping density, and the quantum well thickness. This has important implications for EMR sensor design.