Influence of mechanical stress on the offset voltage of Hall devices operated with spinning current method

The effect of mechanical stress on the offset voltage of a symmetrical CMOS Hall device was measured when operated by the continuous spinning current method. This method allows the expansion of the spatially periodic offset voltage into components of a Fourier series up to the fifteenth order. The influences of stress on these components are caused by piezoresistive effects changing the current distribution in the active region of the Hall sensor. Further influences are due to a stress-dependent thickness modulation of the insulating pn-junction that defines the device geometry. However, measuring the sensor response in four different directions for the bias current proved to be sufficient to eliminate ail stress-dependent contributions to the offset voltages of a CMOS Hall device