Characteristics of Thin-Film Transistors Fabricated on Fluorinated Zinc Oxide

Thin-film transistors fabricated on fluorinated zinc oxide have been found to exhibit improved electrical characteristics. The dependence of the extent of the improvement on the amount of fluorine, precisely controlled using ion implantation, is investigated. At a fluorine concentration of 10²⁰/cm³, transistors with a relatively high field-effect mobility of ~60 cm²/V·s have been realized. The enhancement is attributed to the passivation of carrier traps by fluorine. Fluorine concentration in excess of 10²⁰/cm³ is found to result in degraded transistor characteristics.