Light‐Induced Thin‐Film Transfer Processes Based on Phase Transition of GeSbTe and ITO Sacrificial Layers

Abstract

Abstract In the upcoming ubiquitous era, wearable/flexible electronics are spotlighted to get various types of numerous information in real time. Several researchers have investigated flexible materials, and developed diverse thin‐film transfer methods. However, there are some limitations of the intrinsic material unstabilities, and low production yield. Here, light‐induced thin‐film transfer methods are reported by using new transfer mechanism of phase transition in sacrificial materials. Lift‐off conditions with high‐energy laser are delicately optimized by theoretical calculations and experiments to minimize mechanical/thermal damages of the upper thin‐film devices. The selected sacrificial materials of GeSbTe (GST) and indium tin oxide (ITO) with the 300 nm thickness are delaminated from a transparent and rigid glass substrate by irradiating the excimer laser to the surface of the sacrificial layer. The laser‐based exfoliation mechanism of GST and ITO films are comprehended by various material surface analyses. Eventually, flexible oxide thin‐film transistors (TFTs) are successfully demonstrated through light‐induced exfoliation process, showing the usability of the developed transfer technique to future practical applications.

Keywords

• excimer lasers
• flexible electronics
• light‐induced lift‐off
• thin‐film devices