Low loss multi-wafer vertical interconnects for three dimensional integrated circuits

A low loss multi-wafer vertical interconnect appropriate for a microstrip-based circuit architecture is proposed. This transition has been designed, fabricated and measured on 100 μm thick GaAs substrates. The measurements demonstrate insertion loss of better than 0.2dB and reflection of better than 13.6dB up to 20GHz. Using such a high performance transition allows for a more power efficient interconnect, while it enables denser packaging by stacking the substrates on top of each other, as today´s technologies demand.