Dielectric hafnium oxide improved by supercritical carbon dioxide fluid treatment for pentacene thin-film transistors

This paper explores the application of supercritical carbon dioxide (SCC O2) fluids on enhancing the quality of electron-gun-deposited hafnium oxide (Hf Ox) to fabricate the gate insulator of pentacene-based thin-film transistors (TFTs). The leakage current of Hf Ox film was suppressed effectively after the process of SCC O2 fluids mixed with propyl alcohol and H2 O at 150°C, due to the passivation of Hf dangling bonds. The unfavorable hysteresis in capacitance-voltage curves was not observed, and a higher effective dielectric constant was achieved. Therefore, the pentacene-based TFT with SCC O2 -treated Hf Ox gate dielectric can still exhibit low threshold voltage, superior subthreshold swing, and high transmitting current, even in a low-temperature manufacturing process.