Fabrication And Performance Investigation Of Flexible Single-crystalline Silicon Nanomembrane Thin Film Devices With Nb₂O₅-Bi₂O₃-MgO Ceramics As Gate Dielectrics On Plastic Substrates

Due to their light,portable,excellent mechanical and electrical properties,flexible electronics have attracted a lot of attention recent years.For these flexible devices and circuits which are integrated onto a flexible substrate,thin film transistors are the most important components.On the other hand,crystalline silicon has been widely applied in the fabrication of the flexible thin film transistors because of its high carrier mobilities,compatible fabrication technology with traditional Si based CMOS circuits and low cost.These thin film transistors have been used in large area flexible circuits to realize various functions such as wearable applications,radio frequency identity and flexible displays.However,up to now,there is still limited research on a novel fabrication process about a bottom gate structure transistor.In addition,traditional SiO₂,which must be deposited at a relatively high temperature with a low dielectric constant,is not suitable for most flexible electronics.The consequence is that searching a more suitable alternative for gate dielectric is a challenging work in the world.In this article,authors improve the transfer efficiency and achieve a large scale silicon membrane transfer by enhancing the fabrication process.On basis of the improved technology,a novel bottom gate transistor has been designed,which has a compatible fabrication process with Si based circuits.Moreover,High-k BMN ceramics are utilized as gate dielectrics to recognize high performance transistors with low temperature deposition.The current on/off ratio is over 10⁴,while the threshold voltage is¹.3 V.Most importantly,the carrier mobility is over 200 cm²/vs.Finally,this paper measures and analyzes the performance of transistors by changing the dimension and bending state.With the experimental data,a device model is built to give a theorical guidance for the design of the flexible transistors.