Characterization of room temperature metal microbolometers near the metal-insulator transition regime for scanning thermal microscopy

摘要

Metal microbolometers, used in scanning thermal microscopy, were microfabricated from <20 nm titanium thin films on SiO_2/Si_3N_4/SiO_2 cantilevers. These thin films are near the metal-insulator transition regime such that as the film thickness decreases-the resistance increases and the current-voltage characteristics cross over from sublinear to superlinear. In addition, the temperature coefficient of resistance transitions from positive to negative before it plateaus at a negative value. Thin titanium films exhibit negative temperature coefficient of resistance as high as -0.0067/K which is higher than that of bulk titanium films.