Plasma damage of indium-gallium-zinc-oxide (IGZO) thin film transistor (TFT) was investigated. The IGZO TFT was fabricated and the performance was measured before and after BCl3 and/or Cl2 plasma treatment to evaluate the IGZO damage. The BCl3 and/or Cl2 plasma deteriorated the IGZO TFT performance significantly even after a short exposure time in the plasma. We propose a new wet etching process to remove a source/drain metal without damaging the underlying IGZO layer. The wet etching process can be utilized for the fabrication of IGZO TFT array using a roll-to-roll process via a self-aligned imprint lithography technique.