RF 스퍼터링 시 산소 분압과 RF 파워에 따라 증착 된 a-IGZO/SiO2 선택소자의 전기적 특성 변화

Abstract

This study investigated the effect of oxygen partial pressure and RF power on electrical characteristics a-IGZO/SiO2 selector during a-IGZO deposition. Based on atomic force microscopy (AFM) and photoluminescence (PL) analysis, as oxygen partial pressure increases, the cause of the increase in switching slope (SS) is scattering of oxygen atoms and deposition atoms, increase of electron trap site due to aggregation of minority O2+ during deposition, and trap site of Oi in excess oxygen situation. The decrease in on-voltage (Von) as Ar:O2 ratio increases to 5:5 is the effect of carrier concentration in the a-IGZO thin film through the x-ray photoelectron spectroscopy (XPS). The increase in Von as Ar:O2 ratio increase from 5:5 is not due to the carrier concentration, may be due to the effect of the interface dipole on the difference of oxygen density in the material. The increase in SS as RF power increases during a-IGZO deposition is caused by localized growth of supersaturated deposition atoms that acts as trap site. The increase in Von as RF power increases results in oxygen removal due to the high kinetic energy of deposition atoms.