Effect of Sputtered Oxygen Flux on Electrical Properties of Nanometer-thin indium-tin Oxide Transistors

In recent years, there has been significant attention directed towards field-effect transistors based on ultra-thin oxide semiconductors. In this study, we conducted an investigation into the electrical properties of ultrathin indium tin oxide (ITO) field-effect transistors under different oxygen partial pressures. Our experimental results reveal notable influences of oxygen flow rates on crucial transistor characteristics such as mobility, on/off ratio, and sub-threshold swing. Specifically, at an oxygen flow rate of 5 sccm, we achieved a high field-effect mobility (μ
FE
) of 58.9 cm
²
/V s, a threshold voltage (V
th
) of -8.3 V, and a reasonable on/off current ratio (I
on
/I
off
) of 4.4 × 10
⁴
. Moreover, to elucidate the vital role of oxygen in ultrathin ITO transistors, we utilized nitrogen as an alternative during the sputtering process. These findings provide valuable insights into the magnetron sputtering of nanometer-thin ITO field-effect transistors.