Design and fabrication of high accuracy GaAs Hall effect sensor grown by molecular beam epitaxy

A thin GaAs Hall effect sensor with good thermal stability has been grown by molecular beam epitaxy (MBE). This sensor transduces magnetic flux to a voltage signal. The Hall effect involves passing a current through a layer of semiconductor when a magnetic field is applied perpendicularly to the surface of the layer; a voltage is developed across the sides of the semiconductor which is directly proportional to the applied magnetic field. In order to meet the entire requirement of correct measurement and minimize errors, the GaAs layer was cut into a clover-leaf shape by means of a fine-nozzle sandblaster. The ohmic contacts were then formed by sintering indium into the GaAs layer in the presence of HCl gas.