PECVD Silicon Oxynitride as Insulator for MDMO-PPV Thin-Film Transistors

• Published in: Journal of Integrated Circuits and Systems Vol. 5; no. 2; pp. 116 - 124
• Main Authors: Cavallari, Marco R., Albertin, Katia F., Dos Santos, Gerson, Ramos, Carlos A. S., Pereyra, Inés, Fonseca, Fernando J., De Andrade, Adnei M.
• Format: Journal Article
• Language: English
• Published: 21.11.2020
• ISSN: 1807-1953; 1872-0234
• DOI: 10.29292/jics.v5i2.317

We demonstrate that PECVD SiOxNy with good dielectric properties can replace thermally grown SiO2 in Organic Thin-Film Transistors (OTFT) applications. It can be used on ITO-covered glass or even flexible substrates. Poly [2-methoxy-5-(3’,7’-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) is used as the active layer, due to its wide range of applications such as bulk heterojunction solar cells, light-emitting diodes and light-emitting transistors.We show that charge carrier mobility can be at least two times higher for MDMO-PPV on silicon oxynitride than silicon dioxide, μh 1.1x10-4 cm2/Vs. MDMO-PPV spun from solvents such as chloroform and toluene provide comparable TFT performance on SiOxNy. Preliminary studies of devices with hexamethyldisilazane-treated SiO2 demonstrate that performance can be further improved by the choice of a proper surface treatment.