Effect of Surface Cleaning Process on Wafer Bonding of silicon and Pyrex Glass

Abstract Anodic bonding is a reliable packaging method for MEMS devices and the surface properties of wafer directly affects the bonding efficiency.Therefore, the surface treatment of the wafer to be bonded is a very necessary step.Herein,the effects of three different surface cleaning processes on the wafer surface were investigated by atomic force microscopy, scanning electron microscopy, infrared experiments and anodic bonding experiments.By analysis,in the anodic bonding of the RCA solution cleaned wafer and Pyrex glass,the bonding interface can be more closely attached,the properties of this surface are the best.The anodic bonding experiments of wafer and Pyrex glasses show that the bonding current increases with the applied voltage and the bonding time decreases accordingly.This is most evident in the case of RCA cleaning.From the SEM images, as the bonding voltage increases,the bonding interface becomes more and more uniform and there are no obvious voids and voids.With the influence of strong electric field and temperature field,an irreversible chemical reaction occurs at the bonding interface and a bonding layer is formed, which is the key to the successful bonding.