Degradation and failure analysis of Polysilicon Resistor connecting with Tungsten contact and Copper line

Abstract

The failure mechanism was studied on Polysilicon Resistor - Tungsten contact - Copper line structures. Silicide resistor could fail at high resistive interface of poly/silicide/barrier/metal because thermal mismatching for varied materials. In the case of Silicide_Block resistor, damage nearby the contact proximity (especially at Cu region) was observed, which originated from local Joule heating at the interface. Finite element analysis (FEA) was demonstrated that failure was dependent on current density and Joule heat generation.