Fundamental Research of Nonvolatile Memory utilizing Resistive Switching Property of Nickel Oxide

ニッケル　サンカ　ブツ　ノ　テイコウ　ヘンカ　ヲ　モチイタ　フ　キハツ　セイ　メモリ　ノ　キソ　ケンキュウ

Nishi, Yusuke

岩田, 達哉

Iwata, Tatsuya

木本, 恒暢

Kimoto, Tsunenobu

デンキ　ザイリョウ　ギジュツ　コンダンカイ

ReRAM

アニール

欠陥準位

anneal

defect level

Nickel Oxide (NiO) showing a resistive switching property has recently attracted extensive interest as one of the materials for ReRAM. At first rapid thermal annealing in 02 and Ar gas atmospheres was performed for as-deposited NiO/Pt structures at temperature of 400°C to I00 0℃ During annealing the crystallization ofNiO occurs and the resistance of the films increases. The samples annealed at high temperature especially in Ar gas atmosphere exhibit a few ranges of resistance in the high-resistance state, which indicates that annealing process ofNiO thin films has potential of realization of multiple resistive switching. Moreover, an energy level above a valence band edge and density of defects in NiO thin films deposited on n-Si substrates were characterized by admittance spectroscopy. A Ni0107 thin film turned out to include a localized single defect level. The emission time constant at room temperature of the defect level and the energy level above the valence band edge were 2.3μs and about 170 meV, respectively. This value was equivalent to the activation energy of the resistances in both initial state and high-resistance state at a Pt/Ni01 07/Pt stacking structure. Band conduction with holes thermally excited from the defect level may be dominant.

岩田, 達哉

木本, 恒暢