Finite element analysis of a SWEAT structure with a 3-D, nonlinear, coupled thermal-electric model

The standard wafer electromigration accelerated test (SWEAT) structure for metal integrity or highly accelerated electromigration (EM) testing has complexities that make determination of thermal characteristics difficult. Steady-state SWEAT structure thermal-electric characteristics as might exist for the first several seconds of a test, i.e., without changes due to EM, are discussed. A 3-D, nonlinear, coupled thermal-electric finite element model was developed and solved with the ANSYS software tool to investigate heat flow in several regions of the structure. The finite element model is presented. Correlation with nonlinear thermal material parameters is demonstrated, and the importance of modeling lateral heat flow in underlying oxides is shown. Extraction of thermal parameters for use in the EXTRA thermal model is discussed.<
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