The study influence of parameter of P-type diamond hall sensor synthesized by HFCVD

— This paper is the study of the influence of parameter of p-type diamond Hall sensors, which were synthesized by HFCVD. In this study concentrate on influence of thickness and impurity concentration of response sensitivity to magnetic field. Boron was added in ethyl alcohol as the reactant to obtain p-type diamond film at B/C ratio of 10,000 ppm. The synthesis durations of 6, 12 and 36 hours at the substrate temperature of 750°C were selected to achieve the required diamond film thicknesses of 50, 100 and 150 µm, respectively. The synthetic diamond films were confirmed to be diamond using Raman spectroscopy and the cross sections were analyzed using SEM (Scanning Electron Microscopy). Then, simple p-type diamond Hall sensors were fabricated using four silver electrodes adhered on the diamond film. The ohmic of the electrodes were confirmed by the measurement of electrical properties of electrodes and magnetic field response at three different diamond thicknesses. The response sensitivity to magnetic field were 12, 9 and 6 µV/Gauss, respectively. When the thickness of the p-type diamond Hall sensor increased, the response sensitivity to magnetic field decreased. The thickness 50 µm were selected, Boron was added in ethyl alcohol as the reactant to obtain p-type diamond film at B/C ratio of 15,000, 20,000 and 25,000 ppm. The response sensitivity to magnetic field were 9, 7 and 5 µV/Gauss, respectively.