Derivation of Dielectric Constant and Debye Length of Amorphous Si–In–Zn–O by Analyzing Optical Coefficients

Abstract

Highly transparent amorphous Si-doped InZnO (SIZO) thin film was deposited on glass substrate by RF magnetron sputtering at room temperature. The optical constants of SIZO thin film were measured by the ellipsometry. Various parameters were calculated that result from using refractive index and extinction coefficient. In SIZO material system, dielectric constant of real part (εr) value are larger than dielectric constant of imaginary part (εi) value due to the low extinction coefficient (k) value. In addition, the optical bandgap also showed 3.45 eV calculated using the (αhv)2 vs hv plot. From this result, the transparency of the SIZO thin film in the visible light region was confirmed, the Debye length of the SIZO thin film transistor was calculated, and the change in the effective carrier concentration was confirmed. © 2021, The Korean Institute of Electrical and Electronic Material Engineers.