Creating Thin-Film Silicon on Flexible Substrates using Adhesive Bonding and Wet Etching

A 4" silicon-on-insulator wafer was bonded to a flexible plastic substrate using indirect bonding to fabricate thin-film silicon on a flexible substrate. The bonded materials were annealed at 150oC for 48 hours. The bonding process created stress in the silicon (~20 MPa) at the interface due to thermal mismatch. Thin-film silicon was created by removing substrate material. The interfacial stress increased as the silicon was thinned. Relaxation of the stress resulted in residual defects in the silicon.