Application of Flash Lamp Annealing on Nitrogen-Doped Amorphous Indium-Gallium-Zinc-Oxide Thin Film Transistors

Abstract

Amorphous nitrogenated indium-gallium-zinc oxide (a-IGZO:N) thin films were deposited on highly doped silicon (n+Si) wafer substrates and heat-treated by millisecond flash lamp annealing (FLA) at different preheating temperatures to enhance the electrical characteristics of oxynitride thin film transistors (TFTs). A one-dimensional conduction/radiation heat transfer simulation was conducted to predict the temperature fields in the Si substrate, which indicated that the film temperatures during FLA instantaneously rose above 700 degrees C. The electrical characteristics of the a-IGZO:N TFTs were compared with those produced by conventional furnace annealing of one hour. As a result of the FLA process, a remarkable improvement in the TFT device performance was observed in terms of the electrical output characteristics and transfer curves of the a-IGZO:N TFTs. Morphological analyses were conducted using X-ray diffraction, atomic force microscopy, and field emission scanning electron microscopy, indicating the possibility of partial crystallization of the a-IGZO:N channel layers under high-temperature annealing conditions, but the best TFT performance was found for the amorphous phase of IGZO:N. (c) 2017 The Electrochemical Society. All rights reserved.