Screen printed thick-film nickel-silicon interaction

This paper reports the interaction of scrren printed thick film nickel with N-Si (100), 3-6 ohmcm resistivity both unoxidised and oxidised with windows defifined into it, The nickel film after printing was air dried at 150 C for 10 min and finally air fired at 550 C, 750 C and 850 C in a conveyor furnace with 60 min cycle. The high temperature firing yielded the minimum sheet resistance of 55 mohm/square. The barrier heights and the ideality factors were 0.74, 1.5 ; 0.70, 1.0; 0.69, 1.0; and 0.73, 2.8 at the above temperatures. The contact resistance was found to be lowest, i. e90 ohm squarecm at the firing temperature of 850 C respectively. The SEm combined with EDS of the topo surface and the cross sections of the interface revealed (1) the lead from the printed line flows by 40 micrometers and 100 micrometers at firing temperatures of 750 C and 850 C respectively, (2) the interface reaction zone consisting of Ni2Si is uniform and is 1 micrometer thick. However at 850 C a few V-groves 5 micrometer X 5 micrometer filled with lead and nickel are generated. The possible applications of interactions are suggested.