Reliable peripheral anchor-assisted transfer printing of ultrathin SiO2 for a transparent and flexible IGZO-based inverter

Abstract

This study demonstrates the utility of a printable ultrathin silicon dioxide (SiO2) substrate for developing highly transparent and flexible electronic devices. SiO2 provides a wider thermal process window than that of plastics, which is necessary for producing various electronics. To manipulate this fragile material, we employed a supportive handling substrate and transfer printing process using a sacrificial layer and protruding SU-8 anchors. In particular, we characterized the interfacial stress level and mechanics between the SiO2 substrate and the anchors during the retrieval process. We also manipulated the configuration of the corner of the SiO2 substrate to develop a reliable transfer printing process, which resulted in a high transfer yield with no distortion or fracture of the SiO2 patterns. As an example to demonstrate the utility of this method, we successfully developed a transparent and flexible thin-film inverter based on amorphous indium gallium zinc oxide (IGZO) with an 84.7% average optical transmittance on a polyethylene terephthalate (PET) film with an adhesive layer.