The effect of metallization on the ohmic contact resistivity to heavily B-doped polycrystalline diamond films

Three metallization schemes, namely Al/Si, Ti-Au and TiWN-Au contacts on B-doped polycrystalline diamond films have been compared. After annealing at 450/spl deg/C in nitrogen Al/Si contacts show the lowest contact resistivity in the order of /spl sim/10/sup -7/ /spl Omega/ cm/sup 2/. TiWN-Au contacts were found to be the most stable contact system in view of interdiffusion and oxidation. Ti-Au contacts show a catastrophic interdiffusion at moderate annealing temperatures and strong oxidation at the very surface. High surface boron doping concentrations lead to low contact resistivities. At sufficient high doping levels current transport through the metal-diamond barrier is due to field emission.<
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