Low-Frequency Noise Performance of a Bilayer InZnO–InGaZnO Thin-Film Transistor for Analog Device Applications

In this letter, we present a comparative study of the low-frequency noise behavior of single-layer InGaZnO and bilayer InZnO-InGaZnO thin-film transistors (TFTs). The normalized noise for the bilayer oxide TFT is three times lower than that for the single-layer oxide TFT, mainly due to the higher mobility of the thin interfacial InZnO layer. The carrier number fluctuation is the dominant low-frequency noise mechanism in both devices. The use of a high-mobility bilayer oxide TFT with scaled gate length is still valid for reducing low-frequency noise.