High thermosensitivity of silicon nanowires induced by amorphization

•Silicon films were amorphized by FIB and recrystallized using thermal annealing.•A large negative temperature coefficient of resistance of SiNWs was achieved.•The thermosensitivity is explained using boundary theories for polycrystalline Si.

In this work, we demonstrate highly thermosensitive silicon nanowires (SiNWs) for thermal-sensing applications. Crystalline Si was amorphized by Focused Ion Beam in the fabrication process of the SiNWs, and subsequently recrystallized by a thermal annealing process to improve their electrical conductivity. A temperature coefficient of resistance (TCR) from −8000 ppm/K to −12,000 ppm/K was measured for the SiNWs. This large negative TCR is attributed to the boundary potential barrier of 110 meV between silicon crystallites in the poly crystalline SiNWs.