RESISTIVITY OF BORON-DOPED DIAMOND MICROCRYSTALS

We describe measurements of the electrical resistivity of micron-size crystallites of boron-doped diamond. Electron-beam lithography was emp loyed for writing sample-specific contacts on small, well-faceted diam ond crystals grown by chemical-vapor deposition on silicon substrates. After generating a three-dimensional computer model of the crystallit e, a finite-element analysis was used to calculate the internal electr ostatic potential distribution. Multiterminal resistance measurements, in conjunction with a computed geometrical factor, enabled the absolu te resistivity to be determined. We find that the resistivities obtain ed from two different crystallites agree to better than 10%. The resul ts are compared with transport measurements on a large-area homoepitax ial diamond film grown simultaneously with the crystallites. This meth od can be generalized to obtain electrical transport properties of oth er small, irregularly shaped samples. (C) 1998 American Institute of P hysics. [S0003-6951(98)02819-8].