In–Ga–Zn–O MESFET with transparent amorphous Ru–Si–O Schottky barrier

Rectifying transparent amorphous Ru–Si–O Schottky contacts to In–Ga–Zn–O have been fabricated by means of reactive sputtering without any annealing processes nor semiconductor surface treatments. The ideality factor, effective Schottky barrier height and rectification ratio are equal to 1.6, 0.9 eV and 105 A/A, respectively. Ru–Si–O/In–Ga–Zn–O Schottky barriers were employed as gate electrodes for In–Ga–Zn–O metal–semiconductor field-effect transistors (MESFETs). MESFET devices exhibiting on-to-off current ratio at the level of 103 A/A in a voltage range of 2 V, with subthreshold swing equal to 420 mV/dec were demonstrated. A channel mobility of 7.36 cm2/V s was achieved. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)