A low-temperature-grown TiO₂-based device for the flexible stacked RRAM application

Abstract

Flexible TiO(2) crossbar memory device arrays were fabricated on plastic substrates using amorphous titanium oxide thin films grown by the low-temperature plasma-enhanced atomic layer deposition method. Al/ TiO(2)/Al memory cells on polyethersulfone (PES) showed an enhanced endurance property (up to 10(4) cycles) and low switching voltages compared to the cells on rigid substrates. The multi-stacked memory arrays were constructed by forming the additional Al/ TiO(2)/Al layer on the first memory device layer. Memory cells on each layer exhibited stable switching characteristics and mechanical robustness without interlayer cell-to-cell interference.

Plasma-Assisted Atomic Layer Deposition: Basics, Opportunities, and Challenges

“…Furthermore, plasma-assisted ALD allows for a wider choice of substrate materials to be used, particularly those which are temperature-sensitive. 35,38,39,54,65,163,187,251,252,256,258,286,320,321 D. Good control of stoichiometry and film composition Non-thermally-driven reactions can be induced at the deposition surface due to the nonequilibrium conditions in the plasma, which enables better control of the ALD surface chemistry and of the species incorporated into the film. Therefore, the use of a plasma provides additional variables with which to tune the stoichiometry and composition of the films.…”

Non-volatile organic memory with sub-millimetre bending radius

“…In particular, high-performance flexible non-volatile memories based on various data storage principles such as resistive type [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] , flash 4,[25][26][27][28][29] and ferroelectric [30][31][32][33][34][35][36][37][38][39][40] hold great promise in a variety of emerging applications ranging from mobile computing to information management and communication. While the recent advances in this area are impressive, novel organic materials and electronic device structures that can be tightly rolled, crumpled, stretched, sharply folded and unfolded repeatedly without any performance degradation still need to be developed.…”

Direct observation of microscopic change induced by oxygen vacancy drift in amorphous TiO2 thin films

“…A titanium oxide film on an Al/ SiO 2 / Si substrate at a deposition rate of 0.45 Å/cycle was deposited by means of plasma-enhanced atomic layer deposition ͑PEALD͒ ͑ASM Genitech MP-1000͒. [7][8][9] Various deposition temperatures, ranging from 150 to 250°C, were selected in order to compare the switching characteristics. The 60-nm-thick aluminum electrodes were deposited at the top and bottom by the thermal evaporation method, and cross-bar array structures were formed using metal shadow masks with line widths of 50 and 500 m. The sample with the line width of 500 m was fabricated for the TEM characterizations of the real on/ off states.…”

“…In contrast, devices fabricated at TiO 2 deposition temperatures of 150 and 180°C clearly showed the reversible behavior, as reported by our previous works. [7][8][9] The easy breakdown of the devices fabricated at 200 and 250°C may imply that the state of TiO 2 films is an important factor in determining the reversible BRS properties in our Al/ a-TiO 2 / Al system. Generally, TiO 2 thin films deposited by the ALD method at temperatures below 200°C show an amorphous phase, whereas those fabricated at temperatures above 250°C show a crystalline phase, such as anatase or rutile.…”