Effect of process parameters on phase stability and metal-insulator transition of vanadium dioxide (VO₂) thin films by pulsed laser deposition

Owing to remarkable thermochromic, electrochromic, and photochromic properties which arise from a first-order phase transition from insulator to metal at 68 °C, vanadium dioxide (VO₂) has an enormous range of potential applications. However, due to such narrow thermodynamic stability, there is a major challenge surrounding selective phase deposition of vanadium dioxide thin films. Here, we present a report that establishes precise conditions for the deposition of three major polymorphs of VO₂ by pulsed laser deposition. By a systematic study of the synergistic effects of the deposition conditions using a robust design of experiment (Taguchi design), we are able to deposit the VO₂ (M1), VO₂ (T), and VO₂ (A) phases onto thermal oxide (Si/SiO₂) substrates with remarkable precision. By electrically probing the temperature induced phase transformation from insulator to metal of each of these polymorphs, we find not only a strong dependence on the phase, but that the nature of the deposition conditions influences the magnitude and hysteresis width of the temperature cycle.