Resistive Switching Behavior of Titanium Oxynitride Fabricated Using a Thermal Nitridation Process

Abstract

A titanium oxynitride (TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> ) resistive random-access memory (RRAM) with write-once-read-many-times (WORM) characteristics is proposed. The TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> resistive switching (RS) layer with a thickness of 62 nm was fabricated using a thermal nitridation process of an evaporated Ti metal film. The residual Ti layer with a thickness of 8 nm is used as the bottom contact. The Al/TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> /Ti/n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -Si RRAM shows a large memory window of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> at a low read voltage of 0.2 V. Stable high-resistance state (HRS) and low-resistance state (LRS) are observed in the endurance test for 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> read cycles. High read-disturb immunity can be found for over 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> s. The energy band diagram, carrier conduction and the RS mechanisms of the RRAM are investigated.