Temperature and electric field induced metal-insulator transition in atomic layer deposited VO2 thin films. (October 2017)

• Record Type: Journal Article
• Authors: Tadjer, Marko J.; Wheeler, Virginia D.; Downey, Brian P.; Robinson, Zachary R.; Meyer, David J.; Eddy, Charles R.; Kub, Fritz J.
• Is Part Of: Solid-state electronics. Volume 136(2017)
• Page Start: 30
• Page End: 35
• Publication Date: 2017-10
• Subjects: Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2017.06.018
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: Amorphous ALD vanadium oxide was crystallized with an ex situ anneal under a low oxygen pressure. The crystalline VO2 phase was maintained, while formation of other phases was suppressed. Metal insulator transition was observed as a function of temperature with a high ROFF /RON ratio. Electric field induced reversible phase change correlated with VO2 crystalline quality. Abstract: Amorphous vanadium oxide (VO2 ) films deposited by atomic layer deposition (ALD) were crystallized with an ex situ anneal at 660–670 °C for 1–2 h under a low oxygen pressure (10 −4 to 10 −5 Torr). Under these conditions the crystalline VO2 phase was maintained, while formation of the V2 O5 phase was suppressed. Electrical transition from the insulator to the metallic phase was observed in the 37–60 °C range, with an ROFF /RON ratio of up to about 750 and ΔTC ≅ 7–10 °C. Lateral electric field applied across two-terminal device structures induced a reversible phase change, with a room temperature transition field of about 25 kV/cm in the VO2 sample processed with the 2 h long O2 anneal. Both the width and slope of the field induced MIT I-V hysteresis were dependent upon the VO2 crystalline quality.