Compact modeling of vertical hall-effect devices: electrical behavior

Compact modeling of offset sources in vertical hall-effect devices

“…Up to now, the model does not take any offset source into account. As suggested previously [5], the random offset comes from fabrication process deviations, misalignment of contacts, doping gradient, on chip mechanical stress after packaging, and they can be reduced to contact misalignments. These effective contact misalignments can be modeled through four parameters (ΔL 1 , ΔL 2 , ΔL 3 and ΔL 4 ) that alter the nominal distance between contacts D XY , according to Fig.…”

“…Taking into account all these effects, the I-V characteristics of the non-linear resistors are given by [5]:…”

“…Where K is a technology related parameter [5] and V D is the built-in potential of the N-well/P-sub junction and m is equal to 3/2 for an ideal P-N junction and becomes a fitting parameter between 0 to 3/2 depending of the junction doping profile. R XY is the resistance across contacts #X and #Y, depending of the geometry and the process parameters, and whose computation method is described in [5].…”

“…R XY is the resistance across contacts #X and #Y, depending of the geometry and the process parameters, and whose computation method is described in [5]. Up to now, the model does not take any offset source into account.…”

“…In this context, we recently developed a compact model of the electrical behavior of the VHD [5]. This model differs from other modeling approaches [6][7][8] (finite element modeling, lumped circuit ...) by its relative simplicity: it consists in 10 non-linear resistors and it is tuned through 14 parameters (7 of them being related to the geometry, 5 to the technology, and 2 are fitting parameters) [5]. Among all physical effects that alter the response of the sensor, the zero-tesla offset is one of the most critical [9].…”