CONTACT RESISTANCE RESPONSE SURFACE OF SINTERED AL FILMS ON (100) SILICON

Al-Si contact resistance for (100) p-type Si was studied as a function of sintering gas ambient, temperature, and time. Variables were N//2 vs forming gas (10%H//2, 90%N//2); 540 degree C, 500 degree C, 450 degree C; 10, 20, 30, and 40 minutes. Results showed that forming gas yields higher contact resistance values than does N//2. Away from the Al-Si eutectic point, time and temperature did not appear to be significant variables. The quantum mechanical electron tunneling model for metal-semiconductor contact resistance developed by Yu in 1970 is briefly described. This model predicts very well the range of contact resistance values measured in this experiment. The effects of forming gas can be understood by the addition of a space charge due to H//2 diffusion into the Al film.