Dry etching and low-temperature direct bonding process of lithium niobate wafer for fabricating micro/nano channel device

We have developed dry etching process of lithium niobate (LN) wafer using neutral loop discharge reactive ion etching (NLD-RIE) to fabricate both micro- and nano-channels for investigating proton diffusion enhancement in ferroelectric nanochannels. We have also developed low-temperature direct bonding process between LN wafers. Two-hundred parallel nanochannel array of 200-nm deep and wide and 400-μm long connected to two microchannels (width: 500 μm, depth: 5.9 μm) at the both ends were fabricated. We have succeeded in measuring the proton diffusion coefficient as high as 1.2×10⁻⁸ m²/s.