Recently, much attention has been focused on the development of devices with ultra-thin sample thickness for imperceptible and patchable applications, but the use of inorganic active films in flexible electronics has seen a great obstacle due to brittle mechanical properties during bending, despite better electrical performance and high stability. We report a procedure for fabricating organic electronic devices on ultra-thin polymer substrates using a floating process. This process uses water soluble polyvinyl alcohol (PVA) as a sacrificial layer and the maximum process temperature is increased until around 200 °C, which is a valuable condition for high-quality InGaZnO channels and Al₂O₃ gate dielectrics. The 400 nm PVA coating produced with low molecular weight characteristics had relatively smooth surface roughness and quick floating process. The ultra-thin InGaZnO TFT showed good transfer and reproducible performance under extreme bending conditions due to the use of ultra-thin compliant substrates.