Characterization of TiSi2 Ohmic and Schottky Contacts Formed by Rapid Thermal Annealing Technology

Abstract

The new trend for formation is rapid thermal annealing of sputtered titanium on silicon. Ohmic contacts of to n+ and p+ silicon and Schottky diodes to n‐type silicon were physically and electrically analyzed in order to characterize the RTA process. A four‐terminal Kelvin resistor structure has been used to accurately measure the contact resistance. The redistribution of arsenic and boron‐implanted atoms was monitored during silicidation. Sheet resistance measurements, secondary ion mass spectroscopy, and Rutherford backscattering were all performed to characterize the silicide‐silicon interface. All the results were discussed in comparison with to n+ to p+ contact characteristics. contact resistivity to n+ silicon is found to be equal to contact resistivity to n+ silicon. This result, in contradiction with the theory, can be explained by the difference in As redistribution for each silicide. to p+ contact resistivity is higher than that of to p+ silicon, but this result can be improved by increasing the p+ surface concentration. The measured barrier height of the Schottky diodes is 0.52V, and the diodes show good ideality and low dispersion.