This paper reports on a novel vertical Hall sensor with ultra-low offset (ULOVHS) for the measurement of an in-plane magnetic field component. The sensor consists of four parallel coupled fully symmetric vertical Hall sensors (FSVHS). Each FSVHS is formed by the connection of four identical three-contact vertical Hall elements (3CVHE). As a result, with a bias current of 0.5 mA and after current switching, a mean residual offset of 0.27 μV with a standard deviation of 0.29 μV has been achieved among 40 samples on an 8-inch wafer, which is an improvement of a factor of 16 compared to the FSVHS (4.2±14 μV). Furthermore, the measured current related sensitivity of the novel device is SI = 12.65 V/AT, allowing the detection of magnetic fields down to Bmin = 40 μT without any additional electrical compensation circuitry. This represents the best results to date achieved by a standalone VHS in standard CMOS technology.
Sander, C., Vecchi, M. C., Cornils, M., & Paul, O. (2014). Ultra-low offset vertical hall sensor in CMOS technology. In Procedia Engineering (Vol. 87, pp. 732–735). Elsevier Ltd. https://doi.org/10.1016/j.proeng.2014.11.641