HIGH-TEMPERATURE SILICON HALL SENSOR

A high temperature bulk-silicon Hall sensor is presented in which the minority carrier exclusion effect is exploited to obtain an upper operating temperature limit well exceeding 300-degrees-C whereas regular planar silicon Hall plates suffer from a serious sensitivity decrease at these temperatures due to large leakage currents from the sensor to the substrate. The exclusion effect is discussed and numerical solutions of the transport equations are given which show that exclusion can maintain a significant extrinsic region in a semiconductor slab at temperatures at which the bulk of the semiconductor is intrinsic. The sensitivity of the presented sensor is 10 V/AT which is relatively low but simple means to greatly increase the sensitivity are discussed.