Analysis of Carrier Mobility in Amorphous Metal-Oxide Semiconductor Thin-Film Transistor Using Hall Effect

• Published in: IEEE electron device letters 2020-07, Vol.41 (7), p.1025-1028
• Main Authors: Imanishi, Kota, Matsuda, Tokiyoshi, Kimura, Mutsumi
• Format: Article
• Language: English
• Subjects: amorphous Ga-Sn-O (a-GTO); amorphous metal-oxide semiconductor (AOS); Carrier mobility; Electrodes; Electromagnetism; Electron mobility; Electrons; field-effect mobility (μFE); Gold; Hall effect; hall mobility (μHall); Iron; Mathematical analysis; Metal oxide semiconductors; Percolation; percolation path; Semiconductor devices; Shape; Thin film transistors; thin-film transistor (TFT); Transistors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2020.2993268

Carrier mobility in an amorphous metal-oxide semiconductor (AOS) thin-film transistor (TFT) was analyzed using the Hall effect. First, an amorphous Ga-Sn-O (a-GTO) TFT and that with four electrodes arranged in a square shape are fabricated. Next, a transistor characteristic of the a-GTO TFT is measured, and field-effect mobility ( \mu _{{\text {FE}}} ) is calculated. Moreover, the Hall effect of the a-GTO TFT with the four electrodes is measured using a van der Pauw method, and Hall mobility ( \mu _{{\text {Hall}}} ) is calculated. Finally, it is found that the dependence of \mu _{{\text {FE}}} on the gate voltage ( \text{V}_{{\text {gs}}} ) is similar to that of \mu _{{\text {Hall}}} , and the carrier mobility ( \mu ) increases as V gs increases. In conclusion, it is suggested that \mu in the AOS TFT is strongly subject to the percolation path in the channel layer.