Room temperature bonding of nanostructured silicon wafers and mechanical characterization

Abstract

A new method for bonding of two silicon wafers at room temperature is presented. The technique is based on the interlocking of needle-like structured surfaces. The required nano structure (black silicon) is fabricated using a reactive ion etch process with gas chopping. The needles on the surface have a length of 15-25 µm and a diameter of 300-500 nm with a pitch in the range of their diameters. An external pressure is applied to bond the two aligned wafers at room temperature. The retention force can reach up to 3.8 MPa. Interfacial energy values larger than 2 J/m2 were measured