Low-Temperature-Grown Transition Metal Oxide Based Storage Materials and Oxide Transistors for High-Density Non-volatile Memory

摘要

An effective stacked memory concept utilizing all-oxide-based device components for future high-density nonvolatile stacked structure data storage is developed. GalnZnO (GIZO) thin-film transistors, grown at room temperature, are integrated with one-diode (CuO/lnZnO)-one-resistor (NiO) (1D-1R) structure oxide storage node elements, fabricated at room temperature. The low growth temperatures and fabrication methods introduced in this paper allow the demonstration of a stackable memory array as well as integrated device characteristics. Benefits provided by tow-temperature processes are demonstrated by fabrication of working devices over glass substrates. Here, the device characteristics of each individual component as well as the characteristics of a combined select transistor with a 1 D-1 R cell are reported. X-ray photoelectron spectroscopy analysis of a NiO resistance layer deposited by sputter and atomic layer deposition confirms the importance of metallic Ni content in NiO for bi-stable resistance switching. The CIZO transistor shows a field-effect mobility of 30 cm~2 V~(-1) s~(-1) a V_(th) of +1.2V, and a drain current on/off ratio of up to TO8, while the CuO/lnZnO heterojunction oxide diode has forward current densities of 2 × 10~4 A cm~(-2). Both of these materials show the performance of state-of-the-art oxide devices.