Through-silicon via technologies for interconnects in RF MEMS

In this paper, we describe the application of through-silicon via (TSV) interconnects in Radio Frequency Micro-electro-mechanical systems (RF MEMS). Using TSV technologies as grounding connections, a Ku band miniature bandpass filter is designed and fabricated. Measured results show an insertion loss of 1.9 dB and a bandwidth of 20%. The chip size is 9.6 × 4 × 0.4 mm3. Using TSV as interconnections for 3 dimensional millimeter-wave integrated circuits, a silicon micromachined vertical transition with three layers is presented. TSV, alignment, bonding and wafer thinning technologies are used to fabricate the sample. This transition has an insertion loss of less than 6.7 dB from 26 to 34 GHz and its amplitude variation is less than 2 dB. The total size of the chip is 6.3 × 3.2 mm2.