Photoresist-Assisted Release of Movable Microstructures

A simple but efficient technique to avoid the post-release adhesion problem of movable surface-micromachined structures is reported. A grid pattern of photoresist reinforces microstructures during wet etching of the underlying sacrificial layer followed by rinsing and drying. The photoresist is eventually removed by the dry process. This technique requires minimal modification to the original fabrication process while rendering batch process capability for the release of microstructures. The technique was employed to fabricate comb-drive microactuators and demonstrated considerable improvement in yield.