Enhanced resistive switching phenomena using low-positive-voltage format and self-compliance IrO x /GdO x /W cross-point memories

Debanjan Jana,Hsien-Chin Chiu,Yi-Yan Chen,Amit Prakash,Jer-Ren Yang,Siddheswar Maikap

doi:10.1186/1556-276x-9-12

Debanjan Jana, Hsien-Chin Chiu + Show 4 more

Open Access

https://doi.org/10.1186/1556-276x-9-12

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Abstract

Enhanced resistive switching phenomena of IrOx/GdOx/W cross-point memory devices have been observed as compared to the via-hole devices. The as-deposited Gd2O3 films with a thickness of approximately 15 nm show polycrystalline that is observed using high-resolution transmission electron microscope. Via-hole memory device shows bipolar resistive switching phenomena with a large formation voltage of -6.4 V and high operation current of >1 mA, while the cross-point memory device shows also bipolar resistive switching with low-voltage format of +2 V and self-compliance operation current of <300 μA. Switching mechanism is based on the formation and rupture of conducting filament at the IrOx/GdOx interface, owing to oxygen ion migration. The oxygen-rich GdOx layer formation at the IrOx/GdOx interface will also help control the resistive switching characteristics. This cross-point memory device has also Repeatable 100 DC switching cycles, narrow distribution of LRS/HRS, excellent pulse endurance of >10,000 in every cycle, and good data retention of >104 s. This memory device has great potential for future nanoscale high-density non-volatile memory applications.

Highlights

There is an increasing demand for next-generation highdensity non-volatile memory devices because flash memories are approaching their scaling limits
The W bars with different widths of 4 to 50 μm were patterned by optical lithography and wet etching process, which serve as bottom electrode (BE)
Film, the calculated d spacings are found to be 2.78 Å (101), 2.91 Å (002), and 3.06 Å (100), which are similar (2.69 Å (200), 3.09 Å (111), and 1.89 Å (220)) to those reported in the literature [43]

Summary

Introduction

There is an increasing demand for next-generation highdensity non-volatile memory devices because flash memories are approaching their scaling limits. Among many candidates to replace the flash memory devices, resistive random access memory (RRAM) is one of the promising candidates, owing to its simple metal-insulator-metal structure, fast switching speed, low-power operation, excellent scalability potential, and high density in crossbar structure [1,2,3,4]. It is reported [41] that the cross-point structure has a great potential for high-density memory application in the near future

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