FORMATION OF OHMIC CONTACTS ON SEMICONDUCTING DIAMOND GROWN BY CHEMICAL-VAPOR-DEPOSITION

The current-voltage (I-V) characteristics and the contact resistance R (e) of Au/, Al/ and Mg/chemically vapour deposited semiconducting diam ond contacts were measured. The I-V characteristics of Al/ and Mg/p-di amond contacts changed their properties from an ohmic to a rectifying nature as the resistivity of the semiconducting diamonds increased, wh ile the Au/p-diamond contact was ohmic. An R(c) of less than 10(3) Ome ga cm(2) is found to be necessary to obtain the ohmic contacts on semi conducting diamonds regardless of the metal. The rough estimate of the barrier height phi(B), was also discussed using the results of the R( c) measurement.