Scalable cross-point resistive switching memory and mechanism through an understanding of H2O2/glucose sensing using an IrOx/Al2O3/W structure. Issue 38 (21st September 2017)

• Record Type: Journal Article
• Authors: Chakrabarti, Somsubhra; Maikap, Siddheswar; Samanta, Subhranu; Jana, Surajit; Roy, Anisha; Qiu, Jian-Tai
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 38(2017)
• Page Start: 25938
• Page End: 25948
• Publication Date: 2017-09-21
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c7cp05089e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The resistive switching characteristics of a scalable IrO x /Al2 O3 /W cross-point structure and its mechanism for pH/H2 O2 sensing along with glucose detection have been investigated for the first time. Abstract : The resistive switching characteristics of a scalable IrO x /Al2 O3 /W cross-point structure and its mechanism for pH/H2 O2 sensing along with glucose detection have been investigated for the first time. Porous IrO x and Ir 3+ /Ir 4+ oxidation states are observed via high-resolution transmission electron microscope, field-emission scanning electron spectroscopy, and X-ray photo-electron spectroscopy. The 20 nm-thick IrO x devices in sidewall contact show consecutive long dc cycles at a low current compliance (CC) of 10 μA, multi-level operation with CC varying from 10 μA to 100 μA, and long program/erase endurance of >10 9 cycles with 100 ns pulse width. IrO x with a thickness of 2 nm in the IrO x /Al2 O3 /SiO2 /p-Si structure has shown super-Nernstian pH sensitivity of 115 mV per pH, and detection of H2 O2 over the range of 1–100 nM is also achieved owing to the porous and reduction–oxidation (redox) characteristics of the IrO x membrane, whereas a pure Al2 O3 /SiO2 membrane does not show H2 O2 sensing. A simulation based on Schottky, hopping, and Fowler–Nordheim tunneling conduction, and a redox reaction, is proposed. The experimental I – V curve matches very well with simulation. The resistive switching mechanism is owing to O 2− ion migration, and the redox reaction of Ir 3+ /Ir 4+ at the IrO x /Al2 O3 interface through H2 O2 sensing as well as Schottky barrier height modulation is responsible. Glucose at a low concentration of 10 pM is detected using a completely new process in the IrO x /Al2 O3 /W cross-point structure. Therefore, this cross-point memory shows a method for low cost, scalable, memory with low current, multi-level operation, which will be useful for future highly dense three-dimensional (3D) memory and as a bio-sensor for the future diagnosis of human diseases.