Tantalum nitride-p-silicon high-voltage Schottky diodes

Rectifying contacts between TaN and p-silicon with very high reverse breakdown voltage (V/sub BR/ >700 V) without using any guard ring have been realized. Barrier heights of TaN to both p-type silicon and n-type silicon have been measured at 0.68 and 0.48 eV, respectively. The breakdown voltage V/sub BR/ of TaN to p-silicon diodes, as deposited, is approximately 400 V and decreases to less than 200 V after annealing in hydrogen at 450 degrees C for 30 min. On the other hand, annealing in a nitrogen ambient at 450 degrees C for 30 min. increases the V/sub BR/ of these diodes to more than 700 V. An explanation for the difference in V/sub BR/ is sought in terms of the structural/chemical changes introduced at the interface by the annealing process. The high forward drop of TaN to p-silicon diodes (>1 V at 10 mA) results from the high substrate resistance and the probe contact resistance, and it is being optimized.<
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