Thermal modeling of a polysilicon-metal test structure used for thermally induced voltage alteration characterization

Thermal modeling and simulations were used to analyze the thermal profiles of a polysilicon-metal test structure generated by localized heating with a n infrared laser. Localized laser heating is the basis of a new failure ana lysis technique, thermally induced voltage alteration (TIVA), that can iden tify shorted interconnects in integrated circuits. The modeling results sho w that variations in thermal profiles of the test structure measured by the TIVA technique are due mainly to preferential laser absorption in various locations in the test structure. Differences in oxide thickness also affect the local heat conduction and temperature distribution. Modeling results a lso show that local variation in heat conduction is less important than the absorbed laser power in determining the local temperatures since our test structure has feature sizes that are small compared to the length over whic h the heat spreads. (C) 2000 American Vacuum Society. [S0734-211X(00)18606- 8].