Flexible Thin-film Transistors on Strained Si/SiGe Membranes

Electronics built on flexible polymer substrates have great potential for a number of applications. The largest potential lies in active-matrix flat-panel display applications, because of the continually increasing demand for light weight and robustness from wireless technologies. For the back-plane circuitry of active-matrix organic light emitting diodes (AMOLEDs), high transconductance (g_m ) and high current drive capability are critical requirements to reduce the gate overdrive voltage and to provide higher brightness. These requirements pose great challenges to the currently widely investigated channel materials, such as amorphous Si, poly-Si, and organic semiconductors. Single-crystal Si, on the contrary, offers excellent performance in comparison with the materials mentioned above. Quite recently single-crystal Si has been transferred onto plastic substrate to create thin-film transistors (TFTs). We report here a novel membrane fabrication method that allows us to create strained-Si TFTs on plastic substrate.