Improvement in pH sensitivity of low-temperature polycrystalline-silicon thin-film transistor sensors using H₂ sintering

In this article, we report an improvement in the pH sensitivity of low-temperature polycrystalline-silicon (poly-Si) thin-film transistor (TFT) sensors using an H₂ sintering process. The low-temperature polycrystalline-silicon (LTPS) TFT sensor with H₂ sintering exhibited a high sensitivity than that without H₂ sintering. This result may be due to the resulting increase in the number of Si-OH₂⁺ and Si-O^- bonds due to the incorporation of H in the gate oxide to reduce the dangling silicon bonds and hence create the surface active sites and the resulting increase in the number of chemical reactions at these surface active sites. Moreover, the LTPS TFT sensor device not only offers low cost and a simple fabrication processes, but the technique also can be extended to integrate the sensor into other systems.