Patterned eutectic bonding with Al/Ge thin films for microelectromechanical systems

Abstract

In this article, we report our results using the aluminum/germanium eutectic to create high quality patterned bonds between two silicon dice. The bonds are formed using thin metal layers and with essentially no pressure applied. We have measured bond strength by fabricating and bonding patterned dice. Pull tests were conducted and the force required to separate the bonds was measured and found to be about 1.6×107 Pa. When bonds break, portions of the substrate are removed. Testing of the hermiticity of the bond demonstrated that leak rates below the detection limit of the leak tester (10−9 sccs) are possible.