@inproceedings{50d78d73846842d496afcd9e0284a23e,
title = "Effects of biased irradiation on charge trapping in HfO2 dielectric thin films",
abstract = "This paper reports the low-dose-rate radiation response of Al-HfO2/SiO2-Si MOS devices, in which the gate dielectric was formed by atomic layer deposition (ALD) with 5-nm equivalent oxide thickness. The degradation of the devices was characterized by a pulse capacitance-voltage (CV) and on-site radiation response technique under continuous gamma (γ) ray exposure at a relatively low dose rate of 0.116 rad (HfO2)/s. Compared with conventional CV measurements, the proposed measurements extract significant variations of flat-band voltage shift of the hafnium based MOS devices. The large flat-band voltage shift is mainly attributed to the radiation-induced oxide trapped charges, which are not readily compensated by bias-induced charges produced over the measurement timescales (for timescales less than 5 ms). A negative flat-band voltage shift up to -1.02 V was observed under a positive biased irradiation with the total dose up to 40 krad (HfO2) and with the electric field of 0.5 MV/cm. This is attributed to net positive charge generation in the HfO2 oxide layer. The generated charges are transported towards the HfO2/SiO2 interface, and then form effective trapped holes in the HfO2. Similarly, a positive flat-band voltage shift up to 1.1 V was observed from irradiation under negative bias with an electric field of -0.5 MV/cm. The positive shift is mainly due to the accumulation of trapped electrons. Analyses of the experimental results suggest that both hole and electron trapping can dominate the radiation response performance of the HfO2-based MOS devices depending upon the applied bias. It was also found there was no distinct border traps with irradiation in all cases.",
keywords = "Charge Trapping, HfO, Thin Films",
author = "Yifei Mu and Zhao, {Ce Zhou} and Qifeng Lu and Chun Zhao and Yanfei Qi and Sang Lam and Mitrovic, {Ivona Z.} and Stephen Taylor and Chalker, {Paul R.}",
note = "Funding Information: This research was funded in part by the National Natural Science Foundation of China under the grant no. 11375146 and the platform promotion for Suzhou Municipal Key Lab “New Energy and Environmental Protection Techniques”. Publisher Copyright: {\textcopyright} 2017 Author(s).; 4th International Conference on the Advancement of Materials and Nanotechnology, ICAMN 2016 ; Conference date: 09-11-2016 Through 11-11-2016",
year = "2017",
month = sep,
day = "11",
doi = "10.1063/1.4999899",
language = "English",
series = "AIP Conference Proceedings",
publisher = "American Institute of Physics Inc.",
editor = "Roshidah Rusdi and Mastuli, {Mohd Sufri} and Nurhanna Badar and Norlida Kamarulzaman",
booktitle = "4th International Conference on the Advancement of Materials and Nanotechnology, ICAMN IV 2016",
}