Effect of inter-layer dielectric on thermal reliability in poly-silicon thin film transistors

Highly reliable polycrystalline silicon (poly-Si) thin film transistors (TFTs) were fabricated by silicon nitride as an inter-layer dielectric (ILD), where the thermal conductivity of silicon nitride is considerably higher than that of silicon oxide. The experimental results showed that the threshold voltage of the n-type poly-Si TFT with the proposed silicon nitride ILD was not degraded after high-power stress because the silicon nitride ILD may disperses the heat in the poly-Si TFT channels, which possibly improved the reliability of poly-Si TFTs without sacrificing the electrical characteristics.