PROPERTIES OF PULSED DC SPUTTERED VANADIUM OXIDE THIN FILMS USING A V2O3 TARGET FOR UNCOOLED MICROBOLOMETERS
Open Access
- Author:
- Wells, Kerry E
- Graduate Program:
- Engineering Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Mark William Horn, Thesis Advisor/Co-Advisor
- Keywords:
- sputtering
temperature coefficient of resistance
IR imaging
vanadium oxide
microbolometer - Abstract:
- Vanadium oxide (VOx) thin films are known as feasible materials for sensing applications in uncooled microbolometers. A great deal remains unknown about the relationship between the films’ material properties and the deposition parameters. This study involved the deposition and analysis of VOx films made by pulsed DC magnetron sputtering of a V2O3 target with a 200 W power source at 225 kHz at room temperature. The depositions consisted of thin films made at total pressures varied from 2.5 to 50 mTorr and oxygen partial pressures between 0 and 10%. Electrical, optical and microstructural properties were investigated to determine the effects of varied oxygen partial pressure and total pressure during deposition. Variations of thickness and post deposition annealing and aging were also studied to determine the effects on the film properties. The results of this study showed the temperature coefficient of resistances and resistivity values of the films were in the range of -3 to -5% (K-1) and 10 - 200 kΩ-cm respectively. Both atomic force microscopy and field emission scanning electron microscopy data established the microstructure of the films followed the structure zone model with an increase in columnar size as total pressure was increased. Spectroscopic ellipsometry analysis indicated significant variations in the dielectric functions in the VOx films with similar electrical properties due to variation in the oxygen content of the films. Films deposited for various durations with the same deposition parameters showed a trend of decreasing resistivity with increased thickness. Substantial variations in the electrical properties occurred when some films were subjected to post deposition annealing. Lastly, the study showed that aging while in desiccators did not result in significant variation of the films’ properties.