Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Data storage: Carbon–ferroelectric memory

Nonvolatile memory based on ferroelectric–graphene field-effect transistors is now a step closer to reality

A fundamental component of a field-effect transistor (FET) is the gate dielectric, which determines the number of charge carriers—electrons or electron vacancies—that can be injected into the active channel of the device.

Graphene has recently become the focus of attention as a viable, high-performance replacement for silicon in FETs, and in recent studies on graphene-based FETs, scientists have investigated the use of thin films of a ferroelectric material for the gate dielectric.

Such films offer several interesting advantages for use in graphene-based FETs: their strong electrical polarization makes it possible to introduce a much higher density of carriers than can be achieved using standard dielectrics, and they have remnant electric polarization—a property that could allow graphene–ferroelectric FETs to be used for nonvolatile memory by storing a certain level of carrier density in the absence of an electrical field.

Two collaborating teams from the A*STAR Institute of Materials Research and Engineering and the National University of Singapore, led by Kui Yao and Barbaros Özylmaz, respectively, previously demonstrated a basic graphene–ferroelectric memory device in which the polarization in the ferroelectric film was controlled by the electrical bias applied to the gate terminal. In that structure, a thin ferroelectric film was deposited on top of a graphene layer, where it injects charge carriers and thus modulates the resistance of the graphene. Unfortunately, however, the two distinct resistance states that could be read as an information bit could only be realized by polarizing and depolarizing the ferroelectric film, which presented problems due to the instability of the depolarization state.

Now, the two teams have collaborated to fabricate an improved device[1] that includes an additional silicon dioxide (SiO2) dielectric gate below the graphene layer (see image). The SiO2 gate, a long-standing component in traditional FETs, effectively provides a reference point from which to measure the effect of ferroelectric gating. By monitoring the resistance of the device as a function of the voltages applied to the top and bottom gates, the researchers developed a quantitative understanding of the performance and switching behavior of graphene–ferroelectric FETs. For use as a nonvolatile memory device, the SiO2 dielectric gate also simplifies bit writing by providing an additional background source of charge carriers, allowing the ferroelectric polarization to be switched between two stable states corresponding to two opposite polarization orientations.

The new device developed by the research team achieved impressive practical results, capable of symmetrical bit writing with a resistance ratio between the two resistance states of over 500% and reproducible nonvolatile switching over 100,000 cycles.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering

Journal information

[1] Zheng, Y. et al. Graphene field effect transistors with ferroelectric gating. Physical Review Letters 105, 166602 (2010).

Lee Swee Heng | Research asia research news
Further information:

More articles from Physics and Astronomy:

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Innovative technique for shaping light could solve bandwidth crunch
20.10.2016 | The Optical Society

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Novel mechanisms of action discovered for the skin cancer medication Imiquimod

21.10.2016 | Life Sciences

Second research flight into zero gravity

21.10.2016 | Life Sciences

How Does Friendly Fire Happen in the Pancreas?

21.10.2016 | Life Sciences

More VideoLinks >>>