Study of radiation hardness of HfO2-based resistive switching memory at nanoscale by conductive atomic force microscopy. Issue 11 (November 2015)

• Record Type: Journal Article
• Authors: Lin, Shih-Hung; Wu, You-Lin; Hwang, Yu-Huei; Lin, Jing-Jenn
• Is Part Of: Microelectronics and reliability. Volume 55:Issue 11(2015)
• Page Start: 2224
• Page End: 2228
• Publication Date: 2015-11
• Subjects: Resistance switching memory -- Radiation hardness -- Conductive atomic force microscopy -- Hafnium dioxide -- Gamma-ray -- Oxygen vacancy; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2015.03.009
• Languages: English
• ISSNs: 0026-2714

Abstract

Highlights: We investigated the resistive switching behaviors of RRAM cell with extremely small area before and after γ-ray irradiation. Forming voltage, set voltage, resistance of high- and low-resistance states are all radiation dose-dependent. A comprehensive model was proposed to explain the changes in post-irradiated resistive switching behaviors. Abstract: A resistive switching random access memory (RRAM) with an HfO2 /Ti structure grown on a molybdenum (MO) substrate was fabricated, and a gold (Au) conductive atomic force microscopy (CAFM) tip was used as the top electrode such that the cell area of the resulting RRAM device is as small as 3 × 10 −12 cm 2 . The pre- and post-irradiated resistive switching behaviors of the RRAM device with various HfO2 layer thicknesses were investigated after being subjected to Co 60 γ-ray irradiation with different radiation doses. It is found that the forming voltage ( V forming ), set voltage ( V set ), resistance of high resistance state (RHRS) and resistance of low resistance state (RLRS) of the RRAM device are all radiation dose-dependent. The V forming, V set, RHRS and RLRS all decrease as the radiation dose increases due to increasing radiation-induced oxygen vacancies or defects inside the HfO2 layer. Our experimental results indicate that the HfO2 -based RRAM cell with an extremely small cell area is not actually radiation hard since the operating voltage will change with V forming and V set after irradiation.