We report on the preparation of the first complete extreme temperature Hall sensor. This means that the extreme-temperature magnetic sensitive semiconductor structure is built-in an extreme-temperature package especially designed for that purpose. The working temperature range of the sensor extends from −270 °C to +300 °C. The extreme-temperature Hall-sensor active element is a heavily n-doped InSb layer epitaxially grown on GaAs. The magnetic sensitivity of the sensor is ca. 100 mV/T and its temperature coefficient is less than 0.04 %/K. This sensor may find applications in the car, aircraft, spacecraft, military and oil and gas industries.

Two-dimensional (2D) planar version of the construction of an extraordinary magnetoresistance (EMR) based magnetic field sensor is proposed and verified in practice. The proposed 2D planar construction differs from the standard three-dimensional (3D) constructions by the position of the metallic shunt. In the new construction the metallic thin film of the shunt is coplanar with the sensitive semiconductor thin film. One of the advantages of that physically 2D planar construction is that it can be easily realized with the standard thin-film technology. Another advantage is that it is applicable to the preparation of EMR sensors based on the high mobility electron/hole gas confined in the new electronic materials like graphene and the topological insulator thin films both being physically 2D by nature. The validity of the planar construction is experimentally confirmed for model EMR sensors based on InSb/Ag thin films. Some interesting physical properties of those sensors are also described.