2015 Volume 8 Issue 1 Pages 74-80
We propose a novel fabrication methodology for a hermetic sealing device using an O2 plasma-assisted low temperature Intrinsic-Silicon (I-Si) and glass bonding technique. Glass substrates were used as the cap and base wafers, while I-Si was applied selectively to the contact surface of the cap wafer as an interlayer. A 180-μm-deep cavity was formed in the cap glass by wet etching using a double-layer (photoresist/I-Si) etching mask. I-Si/glass bonding was conducted at 200°C using an I-Si layer-covered glass wafer and a bare glass wafer. Water contact angle measurements and tensile test results showed that the bonding strength increased with promoting surface hydrophilicity through O2 plasma pretreatment. Moreover, scanning acoustic microscope observations revealed that I-Si/glass bonding was achieved successfully without significant voids. Our results indicate that the proposed method could become an indispensable technique for future functional hermetic sealing devices.