GaAs hall element fabricated by ion implantation

A planar-structure Hall element has been fabricated using submicrometer active layers formed by selenium ion implantation in semi-insulating GaAs. Selenium ion implantation was performed at 300°C and the annealing was carried out at a temperature between 750 and 900°C for about 30 rain in H2atmosphere with RF-sputtered silicon oxide on silicon nitride encapsulation. The Hall element generates a very high output voltage, say 5 V for 15 kG at 20 mA, with a small temperature coefficient less than 0.02 percent/°C in a temperature range from -50 to 200°C. The linearity coefficient of magnetic field dependence of the output voltage is smaller than 0.1 percent/kG.