A study on the interface between an amorphous chalcogenide and the electrode: Effect of the electrode on the characteristics of the Ovonic Threshold Switch (OTS)

• Published in: Journal of alloys and compounds 2017-01, Vol.691, p.880-883
• Main Authors: Seo, Juhee, Cho, Seong Won, Ahn, Hyung-Woo, Cheong, Byung-ki, Lee, Suyoun
• Format: Article
• Language: English
• Subjects: Chalcogenides; Interface trap states; Ovonic Threshold Switch (OTS)
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.08.237

We have studied the effect of the electrode material on the switching behavior of the Ovonic Threshold Switch (OTS) composed of metal/amorphous Ge60Se40/metal. The switching voltage is found to depend strongly on the electrode material, showing a much lower value (∼1.74 V) for Mo compared to that (∼5.85 V) of TiN. As the origin, the Schottky barrier and the interface trap states are examined, leading to a conclusion that the latter plays a crucial role. These results are interpreted by a picture of carrier transport at a metal/amorphous chalcogenide interface, providing an effective method to modulate the switching characteristics of the OTS device for various applications. It is shown that the characteristics of an Ovonic Threshold Switch (OTS) device strongly depend on the electrode material and the interface trap states are associated with the dependence on the electrode. [Display omitted] •Strong dependence of the OTS characteristics on the electrode is disclosed.•The origin of the effect of electrode on the OTS characteristics is investigated.•Interface trap states in an OTS are characterized by various methods.•A model is suggested to interpret such an effect of the electrode on OTS characteristics.