A Mild Surface Activation using Vacuum Ultraviolet Irradiation under Redox Gases for Semiconductor Bonding Materials

A technology of surface modification is known that uses 172 nm vacuum ultraviolet light generated from a xenon excimer lamp to modify the surface of a material (Vacuum ultraviolet light and ozone: VUV/O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> treatments). However, in the VUV/O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> modification method, the surface of the treated material becomes hydrophilic as it is covered with oxidizing functional groups due to the action of active oxygen generated by the high-energy vacuum ultraviolet light. At the same time, the original properties of the sample surface are changed. In cases where metals are to be joined, it is desirable to have little organic contamination and no oxide film. In this study, we report the experimental results of surface activation of semiconductor bonding materials using the VUV -Redox method, which irradiates vacuum ultraviolet light in redox gases.