Electrical characterization of through-wafer interconnects

Through-wafer interconnects (TWI) allows 3-D chip stacking enabling integration of multiple chip functions (i.e. opto-electronic, analog or digital) with reduced power and space requirements. To date, non-destructive characterization techniques for determining interconnect integrity and reliability have not been developed. This work examines a specially modified electrical four-point probe for non-destructive characterization of TWI's. Technical challenges and measurement optimization methods are reported.