We demonstrated the nonvolatile memory functionality of nano-crystalline silicon (nc-Si) thin film transistors (TFTs) using mobile protons that are generated by very short time hydrogen neutral beam (H-NB) treatment at room temperature (25 °C). The whole memory fabrication process kept under 50 °C (except SiO2 deposition process; 300 °C). These nc-Si devices exhibited reproducible hysteresis, reversible switching, and nonvolatile memory behaviors in comparison with those of the conventional FET devices. Our study will further provide a useful route of creating memory functionality and incorporating proton-based storage elements onto a probability of next generation flexible memorable electronics such as low power consumption flexible display panel.