Influence of oxygen vacancies in ALD HfO2-x thin films on non-volatile resistive switching phenomena with a Ti/HfO2-x/Pt structure
- Title
- Influence of oxygen vacancies in ALD HfO2-x thin films on non-volatile resistive switching phenomena with a Ti/HfO2-x/Pt structure
- Author
- 최창환
- Keywords
- Resistive switching; RRAM; Hafnium oxide; ALD; Oxygen vacancies
- Issue Date
- 2018-03
- Publisher
- ELSEVIER SCIENCE BV
- Citation
- APPLIED SURFACE SCIENCE, v. 434, page. 822-830
- Abstract
- We report a modulation of oxygen vacancies profile in atomic layer deposition (ALD) HfO2-x thin films by reducing oxidant pulse time (0.7 s-0.1 s) and study its effect on resistive switching behavior with a Ti/HfO2-x/Pt structure. Hf 4f spectra of x-ray photoelectron microscopy (XPS) and depth profile confirm varied oxygen vacancies profiles by shifts of binding energies of Hf 4f5/2 and Hf 4f7/2 main peaks and its according HfO2-x sub-oxides for each device. The ultraviolet photoelectron spectroscopy (UPS) confirms different electron affinity (chi) of HfO2 and HfO2-x thin films, implying that barrier height at Ti/oxide interface is reduced. Current transport mechanism is dictated by Ohmic conduction in fully oxidized HfO2 thin films - Device A (0.7 s) and by Trap Filled Space Charge Limited Conduction (TF-SCLC) in less oxidized HfO2-x thin films - Device B (0.3 s) and Device C (0.1 s). A switching mechanism related to the oxygen vacancies modulation in Ti/HfO2-x/Pt based resistive random access memory (RRAM) devices is used to explain carefully notified current transport mechanism variations from device-to-device. A proper endurance and long-time retention characteristics of the devices are also obtained. (c) 2017 Elsevier B.V. All rights reserved.
- URI
- https://www.sciencedirect.com/science/article/pii/S0169433217332397?via%3Dihubhttps://repository.hanyang.ac.kr/handle/20.500.11754/117912
- ISSN
- 0169-4332; 1873-5584
- DOI
- 10.1016/j.apsusc.2017.11.016
- Appears in Collections:
- COLLEGE OF ENGINEERING[S](공과대학) > MATERIALS SCIENCE AND ENGINEERING(신소재공학부) > Articles
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