Measurement of electron affinity in boron-doped diamond from capacitance spectroscopy

Boron-doped diamond film sample has been grown on (100) silicon substrate using the microwave enhanced chemical vapor deposition method. It is found that the sample has very good material qualities and an excellent (100) surface morphology. Au/diamond Schottky was fabricated on the (100) surface to study electron affinity of the diamond sample. By measuring frequency dependence capacitance-voltage spectroscopy of the Schottky sample in high vacuum and at room temperature, a very small electron affinity of about 0.025 eV and a work function of about 5.165 eV have been obtained for the (100) surface of the diamond sample supposing the diamond band gap energy is 5.5 eV.