Nonvolatile memory characteristics associated with oxygen ion exchange in thin-film transistors with indium-zinc oxide channel and HfO2-x gate oxide

Materials Today Advances

Hongsik Jeong¹  Tae-Sik Yoon¹  Jimin Han²  Joonki Suh²  Hyun-Mi Kim²  Yuri Kim³  Boyoung Jeong³ 

[1] Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea;Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea;Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea;

关键词: Nonvolatile memory;    Oxygen ion exchange;    Thin-film transistor;    Indium-zinc oxide;    Hafnium oxide;   

DOI  :  

来源: DOAJ

【 摘 要 】

Non-charge-storage-based nonvolatile memory characteristics associated with oxygen ion exchange are demonstrated in a thin-film transistor (TFT) composed of an indium-zinc oxide (IZO) channel and an oxygen-deficient HfO2–x gate oxide. A nonvolatile increase in drain current and a reduced threshold voltage are obtained upon application of positive gate voltage, with the opposite characteristics upon application of negative voltage. The device shows nonvolatile retention properties and suitable endurance properties after repeated operations. Modulation of channel conductance occurs as a results of oxygen ion exchange between the HfO2–x gate oxide and the IZO channel, which consequently alters the oxygen vacancy concentration in the IZO channel; these vacancies act as n-type dopants. For comparison, a device with a thin SiO2 layer inserted between the HfO2–x gate oxide and the IZO channel to prevent oxygen ion exchange shows only the increased threshold voltage upon application of a positive gate voltage as a result of electron charging. These results verify the conductance modulation mechanism associated with oxygen ion exchange at the interface of the HfO2–x gate oxide and the IZO channel. In addition, the nonvolatile memory characteristics of the device are indicative of its potential for non-charge-storage-based nonvolatile memory application.

【 授权许可】

Unknown