CHARACTERIZATION OF DOUBLE-LAYER POLYCRYSTALLINE DIAMOND FILMS

Polycrystalline chemical vapour deposition diamond double-layer films consisting of a heavily doped and an undoped diamond film on a p-Si substrate were physically characterised with the aid of Raman spectroscopy, X-ray thin film diffractometry, ellipsometer measurement and secondary ion mass spectroscopy. Electrical measurement of the undoped diamond layer showed activation energies of 0.02 eV over a temperature range from 30 to 200 °C. For sputtered Al contacts, a contact resistivity of 1.1 × 10-5 Ωcm2 was measured at room temperature. The current in the undoped diamond exhibited a space-charge limited characteristic. The I-V characteristic points towards energetic distribution of traps with an average activation energy of 0.04 eV. © 1992.