Improving Performance of All-Carbon-Nanotube Thin-Film Transistors by Low Temperature Supercritical CO2 Fluid Activation

• Published in: IEEE electron device letters Vol. 40; no. 6; pp. 921 - 924
• Main Authors: Zhang, Ziwei, Zhang, Min, Du, Chunhui, Li, Lei, Chang, Kuan-Chang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Activation; activation treatment; All-carbon-nanotube thin-film transistors; Carbon; Carbon dioxide; Carbon nanotubes; Dielectrics; Fluids; Fourier transforms; Infrared analysis; Leakage current; Low temperature; Oxidation; Performance evaluation; Photoelectrons; Semiconductor devices; Silicon; Spectrum analysis; Structural damage; supercritical CO₂ fluid; Thin film transistors; Threshold voltage; Transistors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2019.2912197

In this letter, we propose a novel activation treatment using supercritical CO 2 fluid (SCCO 2 ) to improve the comprehensive performance of all-carbon-nanotube thin-film transistors (TFTs) at low temperature. After the treatment, the subthreshold swing, the threshold voltage, and the leakage current of the devices are decreased. Meanwhile, the mobility and on/off current ratio of the device are improved significantly. We verify the passivation mechanism of the SCCO 2 treatment by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis. The result shows that the SCCO 2 treatment improves the oxidation level, passivates the defects in the dielectric layer, and removes the impurity molecules adsorbed by carbon nanotubes. The SCCO 2 treatment performs component modification for the device by its excellent penetrating and dissolving capabilities without causing the structural damage. It has a great potential to be generally applied to activate TFTs with processing temperature limitation.