Evolution of resistive switching mechanism through H 2 O 2 sensing by using TaO x -based material in W/Al 2 O 3 /TaO x /TiN structure

Somsubhra Chakrabarti, Rajeswar Panja, Sourav Roy, Anisha Roy, Subhranu Samanta, Mrinmoy Dutta, Sreekanth Ginnaram, Siddheswar Maikap, Hsin Ming Cheng, Ling Na Tsai, Ya Ling Chang, Rajat Mahapatra, Debanjan Jana, Jian Tai Qiu, Jer Ren Yang

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Understanding of resistive switching mechanism through H 2 O 2 sensing and improvement of switching characteristics by using TaO x -based material in W/Al 2 O 3 /TaO x /TiN structure have been reported for the first time. Existence of amorphous Al 2 O 3 /TaO x layer in the RRAM devices has been confirmed by transmission electron microscopy. By analyzing the oxidation states of Ta 2+ /Ta 5+ for TaO x switching material and W 0 /W 6+ for WO x layer at the W/TaO x interface through X-ray photoelectron spectroscopy and H 2 O 2 sensing, the reduction-oxidation mechanism under Set/Reset occurs only in the TaO x layer for the W/Al 2 O 3 /TaO x /TiN structures. This leads to higher Schottky barrier height at the W/Al 2 O 3 interface (0.54 eV vs. 0.46 eV), higher resistance ratio, and long program/erase endurance of >10 8 cycles with 100 ns pulse width at a low operation current of 30 μA. Stable retention of more than 10 4 s at 85 °C is also obtained. Using conduction mechanism and reduction-oxidation reaction, current-voltage characteristic has been simulated. Both TaO x and WO x membranes have high pH sensitivity values of 47.65 mV/pH and 49.25 mV/pH, respectively. Those membranes can also sense H 2 O 2 with a low concentration of 1 nM in an electrolyte-insulator-semiconductor structure because of catalytic activity, while the Al 2 O 3 membrane does not show sensing. The TaO x material in W/Al 2 O 3 /TaO x /TiN structure does not show only a path towards high dense, small size memory application with understanding of switching mechanism but also can be used for H 2 O 2 sensors.

Original languageEnglish
Pages (from-to)51-59
Number of pages9
JournalApplied Surface Science
Publication statusPublished - Mar 1 2018
Externally publishedYes


  • Al O layer
  • H O sensing
  • Simulation
  • Switching mechanism
  • TaO switching material
  • WO membrane

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


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