Low-temperature-grown transition metal oxide based storage materials and oxide transistors for high- density non-volatile memory

An effective stacked memory concept utilizing all-oxide-based device components for future high-density nonvolatile stacked structure data storage is developed. GaInZnO (GIZO) thin-film transistors, grown at room temperature, are integrated with one-diode (CuO/InZnO)-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 lowtemperature 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 1D-1R 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 GIZO transistor shows a field-effect mobility of 30 cm² V^-1 s^-1, a Vth of +1.2 V, and a drain current on/off ratio of up to 10⁸, while the CuO/InZnO heterojunction oxide diode has forward current densities of 2×104 Acm ^-2. Both of these materials show the performance of state-of-the-art oxide devices.