Non-Orthogonality and Amplitude Mismatch of Vertical Hall Based Angular Sensors Due to In-Plane Shear Stress

We report on the influence of in-plane shear stress on the output of CMOS vertical Hall devices (VHD) and co-integrated stress sensors implemented in standard 180 nm CMOS technology. Experimental investigations on a torsional bridge setup for an angular sensor frontend with VHD orientations along (110) crystal directions resulted in values of 16.6 degrees of non-orthogonality error per 100 MPa of shear stress. Similarly, with VHD orientations along (100) a relative amplitude change of 16.5% was observed. The results are in agreement with values obtained from FEM numerical simulations.