Multiscale mechanics modeling of direct silicon wafer bonding

Dhirendra V. Kubair,¹ Daniel J. Cole,² Lucio Colombi Ciacchi,^3,4 S. Mark Spearing⁵

¹Computational Dynamic Fracture Mechanics Laboratory, Department of Mechanical and Aerospace Engineering, Utah State University, Logan, UT 84322-4130, USA
²Theory of Condensed Matter Group, Cavendish Laboratory, Cambridge CB3 0HE, UK
³Hybrid Materials Interfaces Group, Faculty of Production Engineering and Bremen Centre for Computational Materials Science, University of Bremen, D-28359 Bremen, Germany
⁴Fraunhofer Institute for Production Technology and Applied Material Research IFAM, D-28359 Bremen, Germany
⁵Engineering Materials Group, School of Engineering Sciences, University of Southampton, Hampshire SO17 1BJ, UK

The direct bonding of macroscopically patterned silicon wafers is studied with a cohesive zone model (CZM), the form and key parameters of which are obtained from molecular dynamics simulations. The CZM is implemented in a spectral scheme. For the case of ideally flat wafer surfaces investigated here, the results are consistent with previous work in which the CZM was derived from an assumption of a continuum water film. This multiscale approach has the potential to model directly the effects of surface roughness, nanotopography and small-scale patterning on the efficacy of direct wafer bonding.

Scripta Materialia 60, 1125 (2009)