Flexible Integrated Circuits Developed by Transferring FDSOI CMOS FETs on Plastic Substrate for CMOS Image Sensors

We report the fabrication process of flexible complementary metal-oxide-semiconductor (CMOS) image sensors by transferring fully depleted silicon-on-insulator CMOS field-effect transistors (FETs) onto a plastic substrate. Our device equips both the high performance of single crystalline silicon CMOS FETs and the flexibility of plastic. The CMOS device layer, thinned down to 6 μm, was successfully transferred to a polyethylene terephthalate substrate without damage or peeling. The developed flexible integrated circuits including CMOS FETs and 101-stage ring oscillators were successfully operated in curved form with a 15 mm radius without performance degradation due to bending. This fabrication process offers potential advancements in creating flexible CMOS image sensors and other flexible CMOS devices, including various sensors, logic circuits, displays, and memories.