講演情報
[15a-P06-5]Atomic Structure of Amorphous Tantalum Oxide by Synchrotron X-ray Techniques
〇Rosantha Kumara1, Sakura Yoshikawa2, Atsushi Shimizu2, Linwei Li2, Takayoshi Katase2, Okkyun Seo1, Takeshi Watanabe1, Osami Sakata1, Atsushi Tsurumaki-Fukuchi3, Toshio Kamiya2 (1.JASRI/SPring-8, 2.Science Tokyo, 3.Hokkaido Univ.)
キーワード：
amorphous oxide semiconductor、tantalum oxide thin films、synchrotron X-rays
Amorphous tantalum oxide (a-TaOx) thin films are critical materials in electronic research, renowned for their low energy consumption, wide bandgap, excellent resistive switching behavior, and exceptional scalability. These properties position them as key candidates for commercial resistive random-access memory (ReRAM) devices. Notably, ReRAM functionality in a-TaOx films emerges only under oxygen pressures (PO2) below 10-2 Pa due to increased diffusion coefficients of tantalum and oxygen ions. This study explores the relationship between PO2 and ion diffusion, focusing on long-range ion rearrangement using atomic-scale structural analyses. Grazing incidence X-ray scattering (GIXS) reveals the amorphous structure. The extended X-ray absorption fine structure (EXAFS) provided insights into Ta coordination and bonding. Coupling GIXS and EXAFS with pair distribution function (PDF) and reverse Monte Carlo (RMC) analyses, we constructed detailed 3D atomic-scale structures, clarifying the correlation between ReRAM functionality and ion rearrangement.