Effects of deposition and annealing conditions on the crystallisation of NiTi thin films by e-beam evaporation

Micro & nano letters

article

Hao Sun¹  Jianjun Luo¹  Zhongjing Ren¹  Ming Lu³  Yong Shi² 

[1] School of Astronautics, Northwestern Polytechnical University;Department of Mechanical Engineering, Stevens Institute of Technology;Center for Functional Nanomaterials, Brookhaven National Laboratory

关键词: titanium alloys;    crystallisation;    shape memory effects;    metallic thin films;    etching;    vacuum deposition;    crystal microstructure;    scanning electron microscopy;    nickel alloys;    annealing;    X-ray diffraction;    electron beam deposition;    differential scanning calorimetry;    annealing;    crystallisation;    nickel-titanium thin films;    e-beam evaporation;    low e-beam deposition rate;    NiTi crystalline structure;    high-precision patterned NiTi thin film microstructures;    low e-beam deposition rate;    P-type (110) silicon substrates;    X-ray diffraction;    differential scanning calorimetry;    SEM image;    microstructures;    shape memory alloy medical devices;    microrobotics;    size 0.5 mum;    NiTi;    Si;   

DOI  :  10.1049/mnl.2020.0004

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

This Letter demonstrates the effects of deposition and annealing conditions on the crystallisation of nickel–titanium (NiTi) thin films deposited by the e-beam evaporation. NiTi thin films of 0.5 μm thick are fabricated on P-type (110) silicon substrates using the e-beam evaporation technique. With the characterisations using the X-ray diffraction method, the results indicate that low e-beam deposition rate and argon employed annealing procedures can be beneficial to the formation of NiTi crystalline structure. Additionally, the as-deposited NiTi thin films without annealing procedures are amorphous, when deposited on the substrates at low temperatures. The differential scanning calorimetry studies show NiTi thin films formed by the e-beam evaporation are Ni-rich. Furthermore, SEM images illustrate that high-precision patterned NiTi thin film microstructures can be fabricated by combining with the e-beam evaporation and lift-off resist methods, without any wet or dry etching procedures. The proposed fabrication process for NiTi thin film microstructures shows great potential for application in shape memory alloy medical devices, as well as the micro-robotics.

【 授权许可】

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