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.