Properties of hydrogenated indium oxide prepared by reactive sputtering with hydrogen gas

We investigate the possibility of fabricating high-mobility hydrogen-doped indium oxide (IO:H) using gaseous hydrogen instead of water vapor during sputtering. A sputtering tool equipped with a residual gas analyzer allows us to monitor the partial pressure of H2, O2 and H2O in the system, and to link the gas composition to the properties of the deposited films. Films with mobilities as high as 90 cm2/Vs and carrier densities of 2.1020 cm-3 (after annealing) were obtained when low hydrogen content was introduced (partial pressure of 4.10-6 mbar) together with argon and oxygen. Increasing the content of hydrogen prove detrimental to the transparency of the film as well as to the electrical properties, as well as the absence of hydrogen.