P-type polycrystalline diamond layers by rapid thermal diffusion of boron

P-type diamond layers have been produced in polycrystalline diamond by mean s of rapid thermal diffusion (RTD) of boron. Using thin film of deposited b oron as the source and temperatures near 1600 degrees C, solid-state diffus ion of boron was achieved, forming conducting layers with average sheet res istances of about 356 Omega/square and diffused-layer thicknesses of about 0.6 mu m. Ohmic contacts to the diffused layers were formed by depositing m olybdenum films before the RTD step so that sintering of contacts occurred simultaneously with the diffusion. The advantages of this approach are that (a) low contact resistances are obtained and (b) only one high-temperature step is involved. Using this technique, molybdenum-diamond Schottky diodes were fabricated and found to have barrier potentials of 2.6 V and ideality factors of 1.6. (C) 2000 American Institute of Physics. [S0003-6951(00)028 07-2].