Advanced flexible CMOS integrated circuits on plastic enabled by controlled spalling technology

We present, for the first time, mechanically-flexible advanced-node CMOS circuits, including SRAM and ring oscillators, with gate lengths <;30 nm and contacted gate pitch of 100 nm. Our novel layer transfer technique called “controlled spalling” is employed as an incredibly simple, low-cost, and manufacturable approach to separate the finished CMOS circuits from the host silicon substrate. The overall performance of the flexible devices and circuits are carefully examined, demonstrating functional SRAM cells down to VDD=0.6V and ring oscillators with record stage delay of ~16ps, the best reported to date for a flexible circuit.