화학공학소재연구정보센터
Current Applied Physics, Vol.17, No.2, 262-266, 2017
Control of positive and negative threshold voltage shifts using ultraviolet and ultraviolet-ozone irradiation
The precise control of the threshold voltage (Vth) required to turn a metal-oxide semiconductor field-effect transistor on/off at the designed voltage was important to ensure that the Val was constant for all the transistors in the circuit. In this study, Vth was adjusted in both the negative and positive directions by manipulating the number of O vacancies on the surface of an oxide nanowire channel using ultraviolet (UV) and UV-ozone (UVO) irradiation. UV irradiation shifted the Vth in the negative direction by an amount that increased with increasing exposure time (-0.96 V at 1 min, 1.42 V at 2 min, and 1.70 V at 3 min), whereas UVO irradiation shifted the Vth in the positive direction by an amount that increased with increasing exposure time (+0.37 Vat 3 min, +0.69 Vat 5 min, and +1.07 V at 10 min). The shifted values of Vth were maintained by passivating the channel region of the oxide nanowire with an octadecylphosphonic acid self-assembled monolayer. (C) 2016 Elsevier B.V. All rights reserved.