Abstract: Porous silicon (PS) was formed on the surface of silicon wafer by electrochemical etching method under different current densities. In order to form VOx/PS/Si structure, vanadium oxide thin films were deposited on PS surface utilizing novel facing targets DC reactive sputtering technique. Field emission scanning electron microscope (FESEM) was utilized to observe the microstructure of PS and VOx/PS/Si structure, the nano-mechanical property of VOx/PS/Si structure was studied by nanoindentor instrument, and the temperature sensitive property was analyzed with resistance-power curves. The results showed that the average pore sizes of PS samples prepared under current densities of 40 and 80 mA·cm-2 were 18 and 24 nm, and the thermal conductivities tested by micro Raman spectroscopy were 3.282 and 1.278 kW·K-1, respectively. The average speeds of resistance varying with power for VOx/PS/Si structure were 60×10⁹ and 100×10⁹ Ω·W-1, and the nano-hardness were 1.917 and 0.928 GPa, respectively. The experimental results indicated that the microstructure of PS had great influence on the nano-mechanical property and temperature sensitivity of VOx/PS/Si structure; this structure formed on PS with high porosity had better temperature sensitivity than PS with low porosity, but a worse mechanical stability.

Key words: Vanadiumoxide, Porous silicon, Microstructure, Nano-mechanical, Temperature sensitivity