Electrical characteristics of TiB/sub 2/ for ULSI applications

The work function of TiB/sub 2/ was measured using Fowler-Nordheim tunneling in MOS capacitors, Schottky diode current measurements, capacitance-voltage techniques, and contact resistance. The resulting data place the Fermi level of TiB/sub 2/ about 0.9 eV below the silicon conduction band. Given this barrier height, Schottky diodes of TiB/sub 2//p-Si exhibit ohmic characteristics, but the contact resistance of TiB/sub 2/ to n/sup +/ junctions is an order of magnitude higher than the generally desired value. Boron outdiffusion from TiB/sub 2/ into underlying silicon was observed at temperatures of 1000 degrees C and greater. Boron diffusion from TiB/sub 2/ into silicon above 1000 degrees C is enhanced compared to the conventionally accepted value of the boron diffusivity.<
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