Vanadium dioxide (VO2), which exhibits a metal–insulator phase transition at 70 °C, is known to alter its physical properties according to its surface morphology and fabrication process. The systematic investigation of a new fabrication method could not only clarify the origin of its phase transition but also advance progress in applications employing VO2 nanostructures. Here, we demonstrate the drastic enhancement of both the surface morphology and hysteresis of VO2 nanostructures composed of nanoparticles, by applying a sputtering deposition fabrication process, followed by lamp annealing. We investigated different growth conditions for VO2, especially using metallic precursor oxidation under a controlled pressure and temperature, and found that each growth condition led to different morphologies, nanoparticle sizes, and phase transition properties (hysteresis width). Despite a slight increase in particle diameter with annealing time and O2 pressure, the particle aggregation was found to substantially decrease. The temperature width of the hysteresis loop obtained by infrared light reflection measurements increased as the aggregation of VO2 nanoparticles decreased. During the cooling procedure, the transition of slightly aggregated VO2 nanoparticles was revealed to be a two-step process, with the lower transition temperature decreasing with an increase in particle isolation. Our results have the potential to elucidate the hysteresis-inducing mechanisms in VO2 and to aid the materialization of novel devices such as passive thermal control and thermal memory devices.