Ambient Stability Enhancement of Thin-Film Transistor With InGaZnO Capped With InGaZnO:N Bilayer Stack Channel Layers

• Published in: IEEE electron device letters Vol. 32; no. 10; pp. 1397 - 1399
• Main Authors: Po-Tsun Liu, Yi-Teh Chou, Li-Feng Teng, Fu-Hai Li, Chur-Shyang Fuh, Shieh, H. D.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Atmosphere; Channels; Devices; Electronics; Exact sciences and technology; in situ back-channel passivation (BCP); InGaZnO (IGZO); Logic gates; Nitrogen; nitrogenated InGaZnO (IGZO:N); Passivation; Retarding; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Stability; Stacks; Stress; Thin film transistors; Transistors; Amorphous material; Oxygen; Ultraviolet radiation; in situ back-channel passivation (BCP); Stacking; nitrogenated InGaZnO (IGZO:N); In situ; n channel; Thin film transistor; Bilayers; Passivation; InGaZnO (IGZO)
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2011.2163181

A thin-film transistor (TFT) with bilayer stack structure of amorphous nitrogenated InGaZnO (IGZO) (a-IGZO:N) on an IGZO channel is proposed to enhance device stability. The a-IGZO:N acting as a back-channel passivation (BCP) is formed sequentially just after the sputter-deposited amorphous IGZO (a-IGZO) film with in situ nitrogen incorporation process. The a-IGZO:N can effectively prevent the a-IGZO channel from exposing to the atmosphere and retarding interactions with ambient oxygen species. Also, the optical energy bandgap of the a-IGZO:N film is decreased due to the addition of nitrogen. This causes the a-IGZO TFT with a-IGZO:N BCP to exhibit high immunity to the ultraviolet-radiation impact.