GAAS HALL SENSORS MADE BY THE MOCVD TECHNIQUE

The ability of Hall sensors to measure a magnetic field and their properties as multipliers have led to many industrial applications. In particular, GaAs sensors offer a wide operating temperature range, a very small Hall voltage temperature coefficient and an excellent linearity with magnetic field. An improved GaAs Hall sensor can be achieved by growing the GaAs layers by the MOCVD (metal organic chemical vapour deposition) technique. MOCVD permits good control and high quality of the material parameters involved in Hall sensor behaviour. A first characterization of the epitaxial material has been accomplished and the GaAs parameters have been measured in the temperature range - 190- + 100-degrees-C, to optimize the sensor performances. The fabrication process is described and the figures of merit of the device (e.g., sensitivity, linearity, temperature coefficients) have been analysed as a function of the material parameters.