Effect of vanadium thickness and deposition temperature on VO2 synthesis using atmospheric pressure thermal oxidation

THIN SOLID FILMS

卷:724

Article

Ashok, P.¹  Chauhan, Yogesh Singh¹  Verma, Amit¹ 

[1] Indian Inst Technol Kanpur, Dept Elect Engn, Kanpur 208016, Uttar Pradesh, India

关键词: Thin films;    Physical vapor deposition;    Vanadium dioxide;    RF sputtering;    Thermal;    Oxidation;    Phase transition;    Electrical characterization;    Resistance switching;   

DOI  :  10.1016/j.tsf.2021.138630

来源: Elsevier

【 摘 要 】

Vanadium dioxide (VO2) is a phase transition material that undergoes a reversible insulator-metal phase transition at - 68 ?C. Atmospheric pressure thermal oxidation (APTO) of vanadium (V) is a simple VO2 synthesis method in which V thin film is oxidized in open air. For an optimum oxidation duration, VO2 films are obtained with good phase transition properties. We recently reported a modified APTO process using a step temperature profile for oxidation (Thin Solid Films 706, 138003 (2020)). We demonstrated an ultra-low thermal budget synthesis of VO2 thin films with good electrical and optical phase transition properties. For a 130 nm roomtemperature RF sputtered V thin film, an optimum oxidation duration of - 30 s was obtained. In this work, we study how the starting V film thickness and deposition temperature affects the optimum oxidation duration. V thin films of varying thickness (15-212 nm) and 120 nm thick V films with varying deposition temperature (-27450 ?C) are prepared using RF magnetron sputtering. These films are oxidized for different oxidation durations and characterized using Raman and four-probe measurements to find the optimum oxidation duration for each deposition condition. We find that the optimum oxidation duration increases with the increase in V film thickness and V deposition temperature. We model the effect of V film thickness and deposition temperature on the optimal oxidation time using a parabolic law which can be used to obtain the optimal oxidation times for intermediate V thicknesses/deposition temperatures.

【 授权许可】

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