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

P -type diamond layers have been produced in polycrystalline diamond by means of rapid thermal diffusion (RTD) of boron. Using thin film of deposited boron as the source and temperatures near 1600 °C, solid-state diffusion of boron was achieved, forming conducting layers with average sheet resistances of about 356 Ω/square and diffused-layer thicknesses of about 0.6 μm. Ohmic contacts to the diffused layers were formed by depositing molybdenum 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.