Ultra-low Power Non-Volatile Resistive Crossbar Memory Based on Pull Up Resistors

Significance Statement

The importance of resistive random access memory which functions by means of a memristor has wide attractive features compared to other memory devices. They are known to function at faster timescale and lower voltage applications coupled with their desired small-sized structures. These attractive features make them practically applicable for challenges faced in non-volatile memory devices.

Despite this, the issue of sneak peak current interference which occurs at larger crossbar arrays lowers the capacity of a resistive random access memory due to increased power consumption. This can be minimized by increasing the resistive switching ratios between the high and low resistant states, but ability of these devices to read and detect data during the switching process which relies on current measurements remains a bane to this approach. It is therefore important to develop ways of controlling these challenges faced from the sneak path current interference.

In line with this, researchers led by Professor Jinho Bae at Jeju National University and in collaboration with Dr. Sangho Shin at Rowan University and Professor Nobuhiko Kobayashi at University of California Santa Cruz proposed a flexible and ultra-low non-volatile resistive random access memory NVRRAM which consists of crossbar memristor with poly (4-vinylphenol) PVP layer and a pull-up resistor connected to each column bar. They made use of the electrohydrodynamic printing technique to fabricate a 3 ´ 3 flexible dimensional non-volatile resistive random access memory array to further ascertain its functionality. The research work is now published in Organic Electronics.

They made investigations on a single bit memory cell; fabricated on a polyethylene terephthalate substrate was investigated upon series connection between the pull-up resistor and memristor. A timing diagram of the single bit read/write cycle was also provided. A low voltage level was set as logic 0 and the high voltage level as logic 1. The write mode voltage was ±2 V while read mode voltage of 0.5 V was applied.

The team observed the current-voltage curve of the poly (4-vinylphenol) based memristor to have a high and low resistance state to be 10 Gῼ and 10 Mῼ respectively, implying a high OFF/ON resistive switching ratio of about a thousand which operated at low operating current of 10-100 nA.

They also observed long retention performance when the high and low resistance states where measured for a period of 180 days. The steadiness observed in the resistance values of both the high and low resistance states was maintained when measured at a time more than 180 days. This was achieved due to their further encapsulation with plydimethylsiloxane.

The non-volatile resistive random access memory also exhibited some level of bendability down to 10mm when tested for 1000 cycles. They also observed very low power consumption less than 8.33 nW which makes them applicable for non-volatile memory technologies.

The authors of the study were able to fabricate a flexible memory device with high resistive switching ratios, ultra-low power consumption coupled with a high level of detection margins in data for reading and writing operations which could be applicable to other non-volatile random access memory device.

Ultra-low Power Non-Volatile Resistive Crossbar Memory Based on Pull Up Resistors - Advances in Engineering

About The Author

Shawkat Ali did his B.Sc. from FUUAST University Islamabad, Pakistan. MS. from National University of Computer and Emerging Sciences, Islamabad, Pakistan, and Ph.D. from Jeju National University, South Korea in 2008, 2012, and 2016, respectively, in Electrical/Electronic Engineering.

He is currently serving as Assistant Professor at the department of Electrical Engineering, NU-FAST, Islamabad campus. His areas of interest includes Nanotechnology, wearable and implantable electronics, flexible electronics, biomedical sensors, resistive memory, energy harvesting and printed electronic devices fabrication.  He has been involved in research throughout his professional carrier and published more than 30 research articles and registered 8 patents.

About The Author

Jinho Bae received his Ph.D. degree from Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea, in 2001. During 1993 and 2002, he was a member of the technical staff at Daeyang Electric Co., Busan, Republic of Korea. During 2006 and 2007, he was a visiting scholar of electrical and computer engineering department of Texas A&M University, Collage Station, TX, USA. During 2013 and 2014, he was a visiting scholar of electrical engineering department of UCSC, Santa Cruz, CA, USA.

Since 2002, he has been a faculty member in the Department of Ocean System Engineering at Jeju National University. His current research interests include functional electronic polymeric materials, printed electronics, layer peeling problem, and optical signal processing.

About The Author

Chong Hyun Lee received his BSc in Electronics Engineering from Hanyang University, Korea, in 1985. He received an MSc in Electrical Engineering from Michigan Technological University, Houghton, MI, USA, in 1987. He received a PhD in Electrical Engineering from KAIST in Daejeon, Korea, in 2002.

He is currently a professor in the Ocean System Engineering Department at Jeju National University, Jeju, Korea. His research interests are in the areas of microwave antenna design, machine learning & pattern recognition, and radar/sonar signal processing. He is a member of the IEEE and the IEEK.

About The Author

Sangho Shin is an Assistant Professor of Electrical Engineering at the Henry M. Rowan College of EngineeringRowan University, Glassboro, New Jersey, USA. Dr. Shin received his Ph.D. degree from the Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea, in 2007, in Electrical Engineering, and prior to joining Rowan he was a faculty member of University of California, Santa Cruz, California, USA. His research interests and activities broadly include the emerging field of memristors enabled nanoelectronic circuit systems; low-power VLSI design and analog/RF integrated circuits; mixed-signal and mixed-technology integrated systems; and the small spacecraft technologies.

At Rowan, Dr. Shin is currently running a NASA sponsored CubeSat project, named MemSat, for its primary mission to evaluate performance of memristor technology in space environment. He authored two book chapters, 50+ journal and conference papers, mostly on the memristive electronics, low-power CMOS integrated systems, and small satellite systems. He is a Senior Member of IEEE. 

About The Author

Nobuhiko P. Kobayashi, a professor at the University of California Santa Cruz (UCSC), joined UCSC in 2008. Immediately after joining UCSC, Kobayashi served on the co-director of Advanced Studies Laboratories – a strategic partnership between UCSC and NASA Ames Research Center – for 3 years. Kobayashi currently oversees his laboratory, Nanostructured Energy Conversion Technology and Research (NECTAR) that focuses on basic and applied research in exploring exotic physical properties emerging from materials tailored at the length scale ranging from 10-9 m to 10-3 m. Target applications include harvesting, converting, storing, generating, and transmitting energy as well as cutting energy consumption by implementing new knowledge at material, device, and sub-system levels potentially offering resources required to drive just about every aspect of the rapidly emerging global economy.

In the past ten years at UCSC, Kobayashi managed a range of projects supported by various U. S. federal agencies including Defense Advanced Research Program Agency, Office of Naval Research, Department of Energy, Advanced Research Project Agency – Energy, NASA, and National Science Foundation. Kobayashi also have extensive collaboration with industrial partners including Hewlett-Packard Laboratories (Palo Alto, California), Structured Materials Industries, Inc. (Piscataway, New Jersey), Lumildes (San Jose, California). Prior to joining UCSC, Kobayashi was involved in developing electronic materials for ultra-high density electrical switches to build memories and logics required for future computing systems at Hewlett-Packard Laboratories. He was also involved in semiconductor nanowire photonics for optical interconnect necessary for advanced computing systems.

Prior to Hewlett-Packard Laboratories, Kobayashi worked at Lawrence Livermore National Laboratory, developing semiconductor materials for both ultra-high speed diagnosis systems required for the National Ignition Facility funded by the U.S. Department of Energy and the optical code division multiple access (optical-CDMA) funded by Defense Advanced Research Project Agency. From 1999 to 2001, Kobayashi was at Agilent Laboratories, developing light emitting diodes, vertical cavity surface emitting lasers, and hetero bipolar transistors for both ultra-wide band fiber-optics and wireless communications.

Kobayashi published over 180 journal and conference papers including more than 20 invited talks and papers and contributed to 4 book chapters, in addition, Kobayashi currently holds 23 U.S. patents. Kobayashi currently serves on program committee members/conference chairs/co-chairs at SPIE Energy Harvesting and Storage, SPIE Image Sensing Technologies, SPIE Optics and Photonics/Nanoscience and Engineering, and World Congress on Engineering and Computer Science. Kobayashi earned his M.S. and Ph.D. degrees in materials science from University of Southern California in 1994 and 1998, respectively. 

Acknowledgements
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2016R1A2B4015627).

REFERENCE

Ali, S., Bae, J., Lee, C.H., Shin, S., Kobayashi, N.P. Ultra-low Power Non-Volatile Resistive Crossbar Memory Based on Pull up Resistors, Organic Electronics 41 (2017) 73-78.

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