Reliability study of AlTi/TiW on polysilicon contacts for high temperature sensors

摘要

This paper deals with the reliability of metal on polysilicon gauges for sensors operating in harsh environments. Particular test structures and characterization equipment have been developed in order to study AlTi/ TiW on highly doped polysilicon contact resistance behaviour and long-term stability. Finite element modeling of current density distribution over the test structures allowed accurate contact resistance extraction. Contact resistance was found to be temperature dependent, having relative good long term stability at 150℃ with a slight (lower than 10%) trend of increase.