Abstract
The formation condition, microstructure, and growth kinetics of the WO x layer for WO x resistive random access memory are investigated. To understand the optimal condition for the rapid thermal O x idation process which forms the WO x layer, various annealing temperature and annealing time are systemically studied through transmission electron microscopy, X-ray diffraction, Raman spectra analyses and electrical characterizations. The growth kinetics for WO x under rapid thermal O x idation is found similar to the one for thermal O x idation on silicon. The electrical forming voltages of the WO x cells are also found independent from the O x ide thickness, which further suggests the switching behavior of WO x resistive random access memory takes place at the interface but not the bulk. © 2012 The Japan Society of Applied Physics.