Steady-state measurement of wafer bonding cracking resistance

A steady-state wedge-opening test has been developed in order to measure the fracture toughness of bonded silicon wafers. Comparison between non-steady-state and steady-state tests is performed. The importance of allowing the rotation of the testing stage is discussed and appears to be essential in order to have the wedge perfectly aligned with the sample. Significant influence of (1) surface treatment; (2) thermal annealing, and (3) crack velocity on the toughness is observed for Si/Si wafer bonding and related to the interface chemistry. (C) 2003 Published by Elsevier B.V