Characterisation and simulation of low temperature Si-Si direct bonding through velcro-like surfaces based on porous silicon

Velcro-like (needle like) surfaces based on porous silicon can result in strong permanent bonding at room temperature with capability of multiple bonding and un-bonding similar to Velcro® principle. However, understanding of the interaction mechanisms between such surfaces is crucial for employing this type of bonding for wafer or chip bonding and IC packing applications. In this paper, a simple Si technology to create Velcro-like surfaces is described and characterized, and the interaction mechanisms between such surfaces are modelled based on Van der Waals force approach.