Effects of Oxygen-to-Argon Flow Ratio During Sputter Deposition of Indium–Gallium–Zinc Oxide on the Stability of Fluorinated Thin-Film Transistors

Plasma-based fluorination treatment has already been shown to enhance the reliability of metal–oxide thin-film transistors (TFTs). Reported presently is the use of nitrogen trifluoride as an alternative to tetrafluoromethane as an agent of fluorination. Investigated also is how reducing the oxygen-to-argon flow-rate ratio during the sputter deposition of an indium–gallium–zinc oxide (IGZO) film enhances the effects of fluorination by retaining more fluorine in the TFT channel region while preventing the detrimental excessive incorporation of fluorine in the gate dielectric. These have led to improvements in positive-bias-temperature-stress stability, thermal stability, and the statistical yield of fluorinated TFTs.