Fabrication and characterization of WSi2/p-si and TaSi2/p-si devices

Thin films Silicides of Tungsten and Tantalum have become very important for IC manufacturing. W and TaSi2 films were deposited on silicon substrates by CVD and Co-sputtering techniques respectively. These films have been characterized using current-voltage technique. The analysis of the obtained experimental measurements has been performed in the light of Schottky-Mott theory. The effects of annealing were studied using Rapid Thermal Processing technique in the temperature range of 500 to 700°C, in nitrogen atmosphere at a constant pressure of 5x10-6 ton for a duration of 30 seconds.The increase in annealing temperature resulted in the formation of ohmic contact evidenced by current-voltage and sheet-resistance measurements. Typical sheet -resistances were found to be in the order of 6-12Q /square for tungsten silicide and 2-7Q /square for tantalum silicide. The RTP technique,as concluded from the results, was found to be very effective in the formation of ohmic contacts