Electrical Behavior of Combinatorial Thin-Film ZrxTa1−xOy

TL;DR

This study explores how changing the composition of ZrxTa1−xOy thin films affects their electrical behavior and resistive switching mechanisms.

Contribution

The paper reveals that a combination of charge trapping and ionic motion governs the resistive switching in mixed ZrxTa1−xOy systems.

Findings

Charge trapping and emission control short-term cycling behavior in ZrxTa1−xOy devices.

Ionic motion contributes to long-term changes in conduction with increased cycling.

ToF-SIMS identified ionic motion as the source of the 'wake-up' behavior in the devices.

Abstract

Combinatorial magnetron sputtering and electrical characterization were used to systematically study the impact of compositional changes in the resistive switching of transition metal oxides, specifically the ZrxTa1−xOy system. Current-voltage behavior across a range of temperatures provided insights into the mechanisms that contribute to differences in the electrical conductivity of the pristine Ta2O5 and ZrO2, and mixed ZrxTa1−xOy devices. The underlying conductive mechanism was found to be a mixture of charge trapping and ionic motion, where charge trapping/emission dictated the short-term cycling behavior while ion motion contributed to changes in the conduction with increased cycling number. ToF-SIMS was used to identify the origin of the “wake-up” behavior of the devices, revealing an ionic motion contribution. This understanding of how cation concentration affects conduction in mixed valence systems helps provide a foundation for a new approach toward manipulating resistive switching in these active layer materials.

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