High temperature coefficient of resistance of low-temperature-grown VO{sub 2} films on TiO{sub 2}-buffered SiO{sub 2}/Si (100) substrates

• Published in: Journal of applied physics Vol. 118; no. 5
• Main Authors: Miyazaki, Kenichi, Suzuki, Megumi, Wado, Hiroyuki, Shibuya, Keisuke, Sawa, Akihito
• Format: Journal Article
• Language: English
• Published: United States 07.08.2015
• Subjects: CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ELECTRON MICROSCOPY; GRAIN GROWTH; GRAIN SIZE; MATERIALS SCIENCE; POLYCRYSTALS; RAMAN EFFECT; SILICON; SILICON OXIDES; SUBSTRATES; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; THIN FILMS; TITANIUM OXIDES; VANADIUM OXIDES; X-RAY DIFFRACTION
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4927746

The introduction of a TiO{sub 2} buffer layer significantly improved the temperature coefficient of resistance (TCR), a measure of the sharpness of the metal–insulator transition, for films of VO{sub 2} grown on SiO{sub 2}/Si (100) substrates at growth temperatures below 670 K. X-ray diffraction and Raman scattering measurements revealed that polycrystalline VO{sub 2} films were formed on the TiO{sub 2}-buffered substrates at low temperatures below 600 K, whereas amorphous films were formed at these temperatures on SiO{sub 2}/Si (100) substrates without a TiO{sub 2} buffer layer. Electron microscopy studies confirmed that the TiO{sub 2} buffer layer enhanced the grain growth of VO{sub 2} films at low growth temperatures. The VO{sub 2} films grown at 600 K on TiO{sub 2}-buffered substrates showed a large TCR of more than 80%/K as a result of the improved crystallinity and grain size of the VO{sub 2} films. Our results provide an effective approach toward the integration of VO{sub 2}-based devices onto Si platforms at process temperatures below 670 K.