Electroresistance effect in MoS2-Hf0.5Zr0.5O2 heterojunctions

Abstract

Pairing two-dimensional semiconductors with ferroelectric films may allow for the development of hybrid electronic devices that would not only exhibit a combination of the functional properties of both material groups but would also reveal unusual characteristics emerging from coupling between these properties. Here, we report the observation of a considerable (up to 103 at 0.8 V read bias) polarization-mediated tunneling electroresistance (TER) effect in Hf0.5Zr0.5O2 (HZO) ferroelectric tunnel junctions (FTJs) employing MoS2 as one of the electrodes. It was found that for this type of hybrid FTJs, a change in resistance upon polarization reversal could be described by Fowler–Nordheim tunneling. The underlying mechanism for the enhanced TER effect is a polarization-mediated accumulation or depletion of the majority carriers at the MoS2/HZO interface, which results in a change in the effective barrier shape seen by the tunneling electrons. Given the compatibility of HfO2-family ferroelectrics with CMOS technology and a possibility of large scale growth and transfer of MoS2 films, our results provide a pathway for fabrication of high-density nonvolatile memory and data storage systems based on hybrid FTJs.

Effect of Film Microstructure on Domain Nucleation and Intrinsic Switching in Ferroelectric Y:HfO2 Thin Film Capacitors

“…[2] Already, a few technological developments using HfO 2based films have been demonstrated: ferroelectric field effect in transistors with the 28-nm gate length, [3] fast and hysteresis-free negative capacitance, [4][5][6][7][8] as well as tunneling electroresistance effect. [9][10][11][12][13][14] Since functionality of the FE-based devices in most cases depends on the electrical switching of the spontaneous polarization, increasing application of the HfO 2 -based FE films calls for a better understanding of the mechanism of polarization reversal in these materials, which is far from being understood. [15][16][17][18] For example, hysteresisfree negative capacitance can only occur if the polarization switches intrinsically, i.e., without domain nucleation and growth.…”

Wake-Up Free Ultrathin Ferroelectric Hf0.5Zr0.5O2 Films

“…The proposed approach could be useful not only for the design of conventional highdensity FRAM and FTJ memory but also for the development of novel devices based on tunnel-transparent ferroelectrics, which require functional materials that suppress ferroelectricity in hafnium oxide (e.g., graphene and other two-dimensional materials [25][26][27]).…”

Modulated optical and ferroelectric properties in a lateral structured ferroelectric/semiconductor van der Waals heterojunction

“…Semiconductors are also crucial for forming a Schottky barrier to obtain a higher TER, which is essential for the FTJ. [19][20][21][22][23][24] For vertical structured FTJ devices, an enhanced TER (∼ 10 3 -10 4 ) can be obtained using the ferroelectric/semiconductor heterojunction. [22][23][24] To the best of our knowledge, no lateral structured ferroelectric/semiconductor FTJ with a higher TER (> 10 4 ) has been reported.…”