Silicon-to-thin film anodic bonding

A process for silicon-to-thin film anodic bonding with polysilicon, silicon oxide, silicon nitride or aluminium as the thin film materials has been developed. Silicon wafers covered with these thin films have been sealed together by anodic bonding using thin sputter-deposited glass layers as sealing material. The bond strengths of the samples have been tested by pull tests. Some samples were exposed to water for 300 h to test the media compatibility. IR microscopy has been shown to be a good method to uncover bonding voids. Bond strength tests of three-inch silicon-to-silicon anodic bonded wafers are shown to be in excellent agreement with the bonding yield expected from IR-microscope inspection.