Metallurgical properties and electrical characteristics of palladium silicide-silicon contacts

Abstract

The fabrication, metallurgical properties, and electrical characteristics of palladium silicide (Pd2Si) contacts to n-type Si have been investigated. Pd2Si/Si contacts are similar in electrical and metallurgical behavior to PtSi/Si contacts, but can be fabricated at much lower temperatures. Pd was found to react readily with Si at 200°C to form a silicide phase which was identified as Pd2Si from X-ray diffraction analysis. The electrical resistivity of the silicide is 40 × 10-6 Ω cm as determined from sheet resistivity measurements. The barrier height at the Pd2Si/Si interface was determined from differential capacitance measurements to be 0.745±0.015 V. Current-voltage measurements and activation energy analysis gave barrier heights within this same range. Contact resistance measurements were made on contacts to Si surfaces with phosphorus doping levels of 2×1020/cm3. Resistance values obtained are comparable to both theoretical predictions and measurements reported on PtSi and Al contacts to Si. © 1971.