Photoelectroscopic Study of Mn Barrier Layer on SiO 2 for Si Wafer Bonding Process

The chemical bonding state of Mn film on SiO 2 , which is expected to be applied as a bonding material for Si wafer, was investigated by x-ray photoelectron spectroscopy (XPS). The as deposited Mn film had unintentionally oxidized surface and interface layer, caused by an air exposure and a redox reaction with SiO x at the SiO 2 surface, respectively. Post deposition anneal (PDA) enhanced the redox reaction between MnO x and SiO 2 . The N 2 plasma treatment eliminates the redox reaction, and enhances the Si-Mn-O bonding formation, which should improve the tensile strength of wafer bonding.