Process-structure-property correlations in pulsed dc reactive magnetron sputtered vanadium oxide thin films

Abstract

Articles you may be interested inPotential for reactive pulsed-dc magnetron sputtering of nanocomposite VOx microbolometer thin films J. Vac. Sci. Technol. A 32, 061501 (2014); 10.1116/1.4894268 Microstructural evolution of thin film vanadium oxide prepared by pulsed-direct current magnetron sputtering J. Appl. Phys. 112, 093504 (2012); 10.1063/1.4759255Enhanced electrical and noise properties of nanocomposite vanadium oxide thin films by reactive pulsed-dc magnetron sputtering Electrical and optical properties of sputtered amorphous vanadium oxide thin filmsCathode hysteresis in the reactive pulsed dc sputtering of a vanadium metal target was investigated to correlate the structural and electrical properties of the resultant vanadium oxide thin films within the framework of Berg's model [Berg et al., J. Vac. Sci. Technol. A 5, 202 (1987)]. The process hysteresis during reactive pulsed dc sputtering of a vanadium metal target was monitored by measuring the cathode (target) current under different total gas flow rates and oxygen-to-argon ratios for a power density of $6.6.W/cm 2 . Approximately 20%-25% hysteretic change in the cathode current was noticed between the metallic and oxidized states of the V-metal target. The extent of the hysteresis varied with changes in the mass flow of oxygen as predicted by Berg's model. The corresponding microstructure of the films changed from columnar to equiaxed grain structure with increased oxygen flow rates. Micro-Raman spectroscopy indicates subtle changes in the film structure as a function of processing conditions. The resistivity, temperature coefficient of resistance, and charge transport mechanism, obeying the Meyer-Neldel relation [Meyer and Neldel, Z. Tech. Phys. (Leipzig) 12, 588 (1937)], were correlated with the cathode current hysteric behavior.

Thermochromic undoped and Mg-doped VO2 thin films and nanoparticles: Optical properties and performance limits for energy efficient windows

“…[42][43][44][45][46] (ii) The film thickness was important, and a large value of d promoted the formation of surface nanostructures, as also seen elsewhere. 47,48 More generally, the surface of a VO 2 film may be different from its main part 49 and the same may be true for the substrate/film interface.…”

Fabrication of VO2-based multilayer structure with variable emittance

“…It has been reported that the V-O system contains multiple compounds and suboxide phases, and sputtering deposition of stoichiometric VO 2 phase by using mass flow controller to regulate oxygen flow rate is experimentally challenging because target "poison" and "hysteresis" effect [17][18][19]. In our experiment, the relative emission intensity of vanadium at 440 nm was used to monitor and feedback control the admission of oxygen.…”

Evaluation of 1/f noise in prospective IR imaging thin films

“…[20] Of the different material systems, thin films of VO x have been extensively investigated, largely due to their low 1/f noise and an existing infrastructure used in the deposition of these thin films. Previous work has extensively looked at the microstructure-property dependence in VO x thin films [5][6] [7][8] [9][10] [11]. These experiments led to an understanding of the microstructure responsible for thin films with improved value of TCR and 1/f noise while still maintaining low values of resistivity.…”