Relation Between Crystallinity And Constituent Distribution Of An Igzo Thin Film

This study examines the crystallinities of indium-gallium-zinc oxide (IGZO) films deposited by sputtering at room temperature under varying conditions and a difference in composition among the films, then we assess the effect of these differences on the FET characteristics. Each sample is found to be nanocrystalline IGZO. The crystallinity and the degree of the c-axis alignment are improved with the increase of the O-2 gas flow ratio in the IGZO deposition. The composition analysis results demonstrate that the ratio of In to Ga and Zn is uneven, and the elements exist separately in all the samples with different conditions. Moreover, every sample is in a composite-like (composite-compound-like) state. An FET, including IGZO deposited with an O-2 gas flow ratio of 50%, which is the condition that improves crystallinity, exhibits a favorable reliability. (C) 2019 The Japan Society of Applied Physics