Batch micropackaging by compression-bonded wafer-wafer transfer

Wafer-wafer transfer of microstructures is demonstrated by gold bump compression bonding. The process is performed at room temperature; 300/spl deg/C-plus is tolerated subsequently. 4-/spl mu/m bump bonds, transferred polysilicon resonators, vacuum-sealed micropackages, and getter structures have been fabricated, as well as multi-level structures built up by successive aligned transfers. Pull strengths of approximately 7/spl times/10/sup 7/ Pa have been measured. 95% yield has been observed in chip-scale transfers, across multiple designs. Sealed micro-packages tolerate external pressures of at least 7.2/spl times/10/sup 6/ Pa without leakage or observable damage.