Electrical characteristics of TaSi2p+Si and TiSi2p+Si contacts formed by rapid thermal annealing

Abstract

Silicidation reactions of sputtered tantalum and titanium thin films on p+Si are performed by rapid thermal annealing with a halogen lamp. Ohmic contacts of TaSi2 and TiSi2 to p+Si are electrically analysed for various contact sizes and annealing temperatures. A four-terminal Kelvin structure has been used to measure the contact resistance accurately. The sheet resistance of the silicide layers was measured with a four-point probe. All the results are discussed in comparison with TaSi2p+Si and TiSi2p+Si contacts. The TiSi2 contact resistance to p+Si is higher than that of TaSi2 to p+Si within the contact sizes studied. This result can be explained by titanium diboride (TiB2) formation at the interface during the heat treatment. However, the measured sheet resistance of the TiSi2 layer is lower than that of the TaSi2 layer. © 1992.