The effect of forming gas annealing on Al/Ti/n-Si contacts

Al/Ti/n-Si contacts without and with post-metallization annealing in forming gas atmosphere are fabricated and characterized. X-ray diffraction measurements are performed in order to identify possible types of silicides that appear after annealing. The results show different phases of Ti silicide, such as TiSi
2
and Al
5
Ti
7
Si
12
. The metal/semiconductor contacts are electrically characterized at different temperatures, over a wide range (60 - 500K). For the as-deposited sample, an ohmic-like behavior is observed over almost the whole temperature domain. Instead, the annealed Al/Ti/n-Si contact exhibits Schottky-like behavior with very good performances, as assessed with our p-diode model. It is evinced that, for the 140 - 420K temperature range and 1μA -100mA current interval, a single dominant contact region is responsible for forward current flow. Under lilA and below 140K, it is necessary to consider two additional contact regions in the p-diode model.