Methodology to estimate TSV film thickness using a novel inline “adaptive pattern registration” method

A novel “adaptive pattern registration” method is developed which gives a reliable estimate of various film thickness in a wafer level TSV. The film thickness are measured using picosecond ultrasonic metrology technique. The adaptive pattern registration method provides higher measurement accuracy at reduced cycle time in comparison to Scanning White-Light Interferometry based technique. It will be shown that TaN/Ta (barrier), Cu Seed and Cu plating film thickness measured at wafer level correlates well to the film thickness at the infield TSV level. The effect of these film thickness on electrical performance of the TSV´s will also be discussed.