Influence of fluorine doping on spin-coated indium gallium zinc oxide (IGZO) thin film properties

Amorphous Indium Gallium Zn-O (a-IGZO) is the most suitable channel material for thin-film transistors (TFTs). In this work, Fluorine (F) doped a-IGZO thin films were deposited on glass substrates using a facile spin -coating sol gel method. The effect of F doping on the structure, electrical and optical properties was investigated. X-ray diffraction (XRD) characterization shows that all deposited IGZO thin films have an amorphous structure and scanning electron microscope (SEM) showed smooth surfaces for all films. Resistivity measurement indicated that F doping systematically decreases the film sheet resistance to achieve 65 Omega/cm(2) while optical characterization show that the deposited thin films transmittance is slightly enhanced to about 85%. Energy -dispersive X-ray spectroscopy (EDS) and photoluminescence spectroscopy (PL) show that F -doping affects the Oxygen vacancy. This latter decreases with increasing F doping. These findings indicate that doping by Fluorine can be a key factor for developing low cost and high performance IGZO TFTs.