Laser transmission bonding of silicon to silicon with metallic interlayers for wafer-level packaging

For packaging of silicon components with low thermal load and high spatial selectivity laser transmission bonding (LTB) of silicon–silicon compounds with intermediate layers using a cw-thulium fiber laser (wavelength 1,940 nm) is investigated. The intermediate layer combination titanium and gold is examined with respect to the bond characteristics and the achievable mechanical properties of the bonded specimens. The tensile strength is measured by using tensile test. Similar specimens bonded with corresponding standard bond process using the same bond geometry are also analyzed in order to compare the measurements.