Test structures for characterization of thermal-mechanical stress in 3D stacked IC for analog design

In this paper we present test structures and measurement techniques that enable extraction of significance of effects expected in 3D TSV technologies. The DAC test structure is optimized to detect Ion changes down to 0.5% due to TSV proximity, TSV orientation, thermal hotspots and wafer thinning/stacking process. The results obtained from the stand-alone MOS devices and the DAC structure clearly indicate the impact of TSV proximity and TSV orientation on the carrier mobility of nearby transistors.