Performance Improvement of GeTex-Based Ovonic Threshold Switching Selector by C Doping

Abstract

In this letter, we fabricated a C-doped GeTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Ovonic threshold switching (OTS) selector in a via-hole structure. The material composition is simple without toxic element doping. Performance of the GeTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> -based selector is improved to be comparable to commercial GeSe-based selectors through C doping. A selector with advantages of low off-current (2 nA), low threshold voltage (1.26 V) accompanying with a big voltage window (0.55 V), high selectivity ( > 4.2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> ), satisfactory endurance (> 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> cycles with 2 mA on-current), low cycle-to-cycle V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> variation and fast operating speed (8.5 ns) was fabricated. Besides, selector with self-limited on-current character was found. Next, reasons behind off-current reduction and consistency improvement by using C doping were studied by First-principles calculations.