ISBN 978-3-8439-4363-5

978-3-8439-4363-5, Reihe Nanotechnologie

Karsten Fleck
The Influence of Local Heating on the Switching Kinetics of Resistive Switching Oxides

182 Seiten, Dissertation Rheinisch-Westfälische Technische Hochschule Aachen (2019), Softcover, A5

Zusammenfassung / Abstract

Due to the increasing importance of information technology the amount of data in the world is growing at an ever rising pace. This development drives the search for new nonvolatile memory technologies of which redox-based resistive memory devices (ReRAM) are among the most promising concepts currently under discussion. Compared to conventional NAND flash they are superior in key aspects like endurance, energy consumption, scalability and write/read times.

In ReRAM information is stored in form of the resistance of the device, which can be switched repeatedly between a low resistive state (LRS) and a high resistive state (HRS) by applying appropriate voltage signals. This resistance change occurs due to ionic movement of defects in a conductive filament. The operation requires different polarities for the SET (switching into the LRS) and the RESET (switching into the HRS) process.

Identifying the limiting factors is crucial for the design of fast switching, energy efficient, and long-term stable ReRAM devices. By analyzing the current response to the applied voltage pulses, important insights into the dynamics of the switching process can be gained.

Therefore, this work presents detailed studies of the switching kinetics of valence change resistive switches covering up to 14 orders of magnitude in time on different model materials. In order to achieve this task, pulse measurement schemes were developed that allowed dedicated analysis of the SET and RESET processes.

It is demonstrated that local Joule heating and the resulting increase in oxygen vacancy mobility are the dominant factor. To separate the influences of the applied electrical field and temperature the SET switching kinetics are investigated at different temperatures. In order to increase the temperature range and to reduce the influence of different temperatures on the prepared HRS, a new experiment is introduced that allows cell temperature to be increased by several 100 °C within 100 ns.