Backside Thinning Process Development for High-Density TSV in a 3-Layer Integration

This paper describes recent developments in the field of high density Through Silicon Vias (TSV) with a focus on the backside thinning flow (grinding, CMP, metrology) for TSV depths of 6μm or lower. Stringent process control was implemented from grinding to CMP finishing steps to obtain remarkably low silicon Total Thickness Variations below 1μm.