Deposition Of VO₂ And Test

VO2 is a special function material, which undergoes a semiconductor-metal phase transition approximately at 68 degrees Celsius which is near room-temperature. The transition is accompanied with abrupt changes in its electrical and optical properties.VO2 can be used in many fields. VO2 thin film is adopted for the bolometer material of uncooled infrared (IR) Focal Plane Array (FPA), and the product has already been developed in developed countries and equipped in their army. Utilizing the sharp and reversible optical switching in the IR region of the spectrum, phase transition optical switch can be developed using VO2 as the function material, which has switch time of ns grade and can be used in high-speed optical communication promisingly. VO2 thin film is also used in anti-laser protection technology to safeguard the satellites from laser attack, and the significance is obvious and great to modern warfare. The domestic study of VO2 remains lower level, because the fabrication and test of high quality VO2 is difficult.In this thesis, the fabrication and test of VO2 thin film is investigated. Reactive sputter deposition and anneal are the main processes of the fabrication. The main process parameters are enumerated, and the effect of process parameters on VO2 quality is also discussed. It is pointed out that the pressure of O2 and Ar in sputter chamber and the anneal temperature are key factors. The quality of VO2 is affirmed by test of phase transition. The ratio of resistance change is tested using Four Probes Method. The average change reaches 103, and is near to 104 of the theory estimation. To test optical property, a test environment is established using fiber, laser emitter and detector. Using contacted heating method, ratio of optic permeation change is tested as 4~5dB, while 11dB is reported. Micro-heating structure is invented to improve the heating method, and 10dB is got. This shows that the VO2 thin films can be put into practice use.The attempt of two applications is briefly given at last.