Low temperature bonding techniques for MEMS applications

Direct bonding of two mirror-polished wafers, without any external applied energy and at low temperature, is an attractive technique for the new generation of ICs, due to the flexibility that the technique offers. This technique can be used for advanced CMOS applications and for MEMS ones, that are MOS compatible. The bonded structure can be obtained using wet or dry activation techniques. The aim of the paper is to provide a method that assures pairs of bonded wafers in case of using a normal thick wafer (/spl sim/300 /spl mu/m) and a thin one (less than 100 /spl mu/m).