Bendability of single-crystal Si MOSFETs investigated on flexible substrate
ABSTRACT This letter reports on a device layer transfer (based on thermal bonding and grinding backside Si) process and device characteristics of Si MOSFETs on a flexible substrate, focusing mainly on the mechanical bendability of the device and resistance to fatigue. The results demonstrated a well-optimized bonding process, as indicated by the nearly indiscernible performance difference (e.g., subthreshold slope, Vth, and Idsat) before and after the bonding of Si with the flexible substrate. The device characteristics indicate excellent bendability of Si MOSFETs on flexible substrate (e.g., for radius tested down to ±72 mm) and good immunity to fatigue (e.g., negligible performance drift tested up to ∼103 bending cycles with a radius of ±126 mm). Results suggest the feasibility of this approach in achieving high-performance MOSFETs for applications in performance-sensitive and flexible electronics.