HERMETIC PACKAGING OF MEMS WITH THICK ELECTRODES BY SILICON-GLASS ANODIC BONDING

摘要

Thick electrodes, which are widely used in micro-electro-mechanical system (MEMS) devices, create serious surface imperfection and would result in a low-quality bond or even debonding. In this work, the influence of electrode thickness on hermetic sealing was investigated. Two approaches to realise hermetic sealing via anodic bonding of silicon to glass with thick electrodes are presented Embedded electrode is one method in which metal was deposited on shallow trench etched on the surface of wafers and planarisation of bonding surface was performed with a Chemical Mechanical Polishing (CMP) process. Another approach, called vertical via electrode method, is to form vertical electrodes through vias by deposition and patterning of metal film.