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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.

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The idea of a raster pattern magnetoresistor made of thin films of III–V compounds and a metallic layer has been known for over fifty years. Based on this knowledge, we present the construction of a magnetoresistor made of combined graphene and metallic strip patterns. The presented device is implemented using a monolayer of graphene epitaxially grown on a semi-insulating substrate. A graphene strip pattern magnetoresistor gives a promising wide range of practical applications due to its very high sensitivity combined with the mono-atomic thickness of the sensitive layer, the simplicity of realization, and a very convenient principle of sensor operation assuming only the usage of two electrical terminals.

In this paper, we report on the double Hall sensor structure (DHSS) in which the voltage offset can be effectively reduced. The DHSS is composed of two standard Hall sensors that are activated with two currents from electrically independent current sources. The operation principle of the DHSS is explained in detail, and the concluded properties of the DHSS are confirmed in the experimental part of the paper. The measurements are performed on DHSSs based on InSb thin films. The offset is reduced by about three orders of magnitude. The minimum value of the reduced offset obtained is 10 μV. It appears that the minimum reduced offset is limited by the electric noise. The advantage of DHSS is that it can be manufactured with the standard thin film technology enabling effective miniaturization of the system. The DHSS can effectively be used for the measurements of the Hall effect in ultra-thin layers containing the two dimensional electron gas, such as the epitaxial graphene.

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.

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