Stress-Free Detachment of Flexible Substrate from Glass Carrier Using CO2 Point Laser for Large-Area Applications

A novel detachment method is presented for flexible substrates from glass carrier wafers using a CO2 point laser. In a conventional laser lift-off process, laser-induced illumination and thermal stress degrade device performance. In this approach, a point laser is applied on the edge of the flexible substrate, where electrical components do not exist, and thus, no performance degradation occurs during the laser process. In addition, the carrier surface properties are modified to control the adhesion force between the flexible substrate and the glass carrier. A spin-on-dielectric layer (SOD) is utilized, and Ar ion bombardment is performed on SOD. The point laser detachment method is demonstrated in flexible thin-film transistors, and no change is observed in the electrical characteristics before and after detachment from the carrier wafer.