Effect of annealing temperature on structural and electrical properties of high-κYbTi_xO_ygate dielectrics for InGaZnO thin film transistors

Abstract

This paper describes the effect of annealing temperature on the structural properties and electrical characteristics of high-κ YbTi x O y gate dielectrics for indium-gallium-zinc-oxide (IGZO) thinfilm transistors (TFTs). X-ray diffraction, x-ray photoelectron spectroscopy and atomic force microscopy were used to study the structural, chemical and morphological features, respectively, of these dielectric films annealed at 200, 300 and 400 °C. The YbTi x O y IGZO TFT that had been annealed at 400 °C exhibited better electrical characteristics, such as a small threshold voltage of 0.53 V, a large field-effect mobility of 19.1 cm 2 V −1 s −1 , a high I on /I off ratio of 2.8 × 10 7 , and a low subthreshold swing of 176 mV dec. −1 , relative to those of the systems that had been subjected to other annealing conditions. This result suggests that YbTi x O y dielectric possesses a higher dielectric constant as well as lower oxygen vacancies (or defects) in the film. In addition, the instability of YbTi x O y IGZO TFT was studied under positive gate-bias stress and negative gate-bias stress conditions.

Uniform dehydrogenation of amorphous silicon thin films using a wide thermal annealing system

“…Diverse semiconductor materials such as metal oxide and silicon-based films have been investigated as a channel layer of thin-film transistors (TFTs) for display [1][2][3]. Among these materials, silicon-based thin films have realized functional applications and industrialized in display.…”