Mechanical and electrical properties of GeSb2Te4 film with external voltage applied

• Published in: Applied surface science Vol. 285; pp. 532 - 537
• Main Authors: Cheng, Guang-Gui, Zhang, Zhong-Qiang, Ding, Jian-Ning, Ling, Zhiyong, Chen, Yu-Bing
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.11.2013; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electric caused phase change; Exact sciences and technology; GeSb2Te4 film; Mechanical and electrical properties; Nanoindentation; Phase change shrinking; Physics; GeSb2Te4 film; Phase change shrinking; Mechanical and electrical properties; Electric caused phase change; Nanoindentation; Te; Phase transformations; film; GeSb
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2013.08.088

•The pile-up phenomenon was observed during indenting without voltage applied.•The hardness and elastic modulus increases with the load without voltage applied.•Resistance of the film decreased in 4 orders of magnitude when given voltage applied.•A shrinking region of about 2.5μm in radius appeared at phase change region. A GeSb2Te4 (GST) film was deposited by RF magnetron sputtering with microwave electron cyclotron resonance plasma chemical vapor deposition equipment. Mechanical and electrical properties together with the morphologies of the film were studied by a nanoindenter which was equipped with nano-electrical contact resistance (nano-ECR) tool and atomic force microscope (AFM). Results show that when no voltage applied between sample and indent tip during indenting, the pile-up phenomenon was observed, the hardness and elastic modulus increases with the load mainly due to the underestimate of the contact area; when external voltages of −7V, −8V, −9V, −10V were applied, the resistance of the film decreased with applied voltages in about four orders of magnitude, while the elastic modulus increased from 159GPa to 233GPa, this changing in mechanical and electrical properties demonstrated that phase change happen during intending, a shrinking region with radius of about 2.5μm was observed around the indentation when −8V applied. Furthermore, indent load can also promote the phase change at given negative voltage.