Low resistance ohmic contacts to amorphous IGZO thin films by hydrogen plasma treatment

► The contact resistivity was decreased to 9.94 × 10− 5 Ω cm2 by H2 plasma treatment. ► The process was carried out at room temp. without any step of thermal treatment. ► The mechanism of enhancing the contact resistance was clarified with XPS results. ► HCl treatment eliminated In clusters formed on surface, improving transmittance.