Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

An easy, scalable and direct method for synthesizing graphene in silicon microelectronics

22.07.2015

Korean researchers grow 4-inch diameter, high-quality, multi-layer graphene on desired silicon substrates, an important step for harnessing graphene in commercial silicon microelectronics

In the last decade, graphene has been intensively studied for its unique optical, mechanical, electrical and structural properties. The one-atom-thick carbon sheets could revolutionize the way electronic devices are manufactured and lead to faster transistors, cheaper solar cells, new types of sensors and more efficient bioelectric sensory devices.


This is a Wafer-scale (4 inch in diameter) synthesis of multi-layer graphene using high-temperature carbon ion implantation on nickel / SiO2 /silicon.

Credit: J.Kim/Korea University, Korea

As a potential contact electrode and interconnection material, wafer-scale graphene could be an essential component in microelectronic circuits, but most graphene fabrication methods are not compatible with silicon microelectronics, thus blocking graphene's leap from potential wonder material to actual profit-maker.

Now researchers from Korea University, in Seoul, have developed an easy and microelectronics-compatible method to grow graphene and have successfully synthesized wafer-scale (four inches in diameter), high-quality, multi-layer graphene on silicon substrates. The method is based on an ion implantation technique, a process in which ions are accelerated under an electrical field and smashed into a semiconductor. The impacting ions change the physical, chemical or electrical properties of the semiconductor.

In a paper published this week in the journal Applied Physics Letters, from AIP Publishing, the researchers describe their work, which takes graphene a step closer to commercial applications in silicon microelectronics.

"For integrating graphene into advanced silicon microelectronics, large-area graphene free of wrinkles, tears and residues must be deposited on silicon wafers at low temperatures, which cannot be achieved with conventional graphene synthesis techniques as they often require high temperatures," said Jihyun Kim, the team leader and a professor in the Department of Chemical and Biological Engineering at Korea University. "Our work shows that the carbon ion implantation technique has great potential for the direct synthesis of wafer-scale graphene for integrated circuit technologies."

Discovered just over a decade ago, graphene is now considered the thinnest, lightest and strongest material in the world. Graphene is completely flexible and transparent while being inexpensive and non-toxic, and it can conduct electricity as well as copper, carrying electrons with almost no resistance even at room temperature, a property known as ballistic transport. Graphene's unique optical, mechanical and electrical properties have lead to the one-atom-thick form of carbon being heralded as the next generation material for faster, smaller, cheaper and less power-hungry electronics.

"In silicon microelectronics, graphene is a potential contact electrode and an interconnection material linking semiconductor devices to form the desired electrical circuits," said Kim. "This renders high processing temperature undesirable, as temperature-induced damage, strains, metal spiking and unintentional diffusion of dopants may occur."

Thus, although the conventional graphene fabrication method of chemical vapor deposition is widely used for the large-area synthesis of graphene on copper and nickel films, the method is not suited for silicon microelectronics, as chemical vapor deposition would require a high growth temperature above 1,000 degrees Celsius and a subsequent transfer process of the graphene from the metallic film to the silicon.

"The transferred graphene on the target substrate often contains cracks, wrinkles and contaminants," said Kim. "Thus, we are motivated to develop a transfer-free method to directly synthesize high quality, multilayer graphene in silicon microelectronics."

Kim's method relies on ion implantation, a microelectronics-compatible technique normally used to introduce impurities into semiconductors. In the process, carbon ions were accelerated under an electrical field and bombarded onto a layered surface made of nickel, silicon dioxide and silicon at the temperature of 500 degrees Celsius. The nickel layer, with high carbon solubility, is used as a catalyst for graphene synthesis. The process is then followed by high temperature activation annealing (about 600 to 900 degrees Celsius) to form a honeycomb lattice of carbon atoms, a typical microscopic structure of graphene.

Kim explained that the activation annealing temperature could be lowered by performing the ion implantation at an elevated temperature. Kim and his colleagues then systematically studied the effects of the annealing conditions on the synthesis of high-quality, multi-layer graphene by varying the ambient pressure, ambient gas, temperature and time during the treatment.

According to Kim, the ion implantation technique also offers finer control on the final structure of the product than other fabrication methods, as the graphene layer thickness can be precisely determined by controlling the dose of carbon ion implantation.

"Our synthesis method is controllable and scalable, allowing us to obtain graphene as large as the size of the silicon wafer [over 300 millimeters in diameter]," Kim said.

The researchers' next step is to further lower the temperature in the synthesis process and to control the thickness of the graphene for manufacturing production.

###

The article, "Wafer-scale synthesis of multi-layer graphene by high-temperature carbon ion implantation," is authored by Janghyuk Kim, Geonyeop Lee and Jihyun Kim. It will be published in the journal Applied Physics Letters on July 21, 2015 (DOI: 10.1063/1.4926605). After that date, it can be accessed at: http://scitation.aip.org/content/aip/journal/apl/107/3/10.1063/1.4926605

ABOUT THE JOURNAL

Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. See: http://apl.aip.org

Media Contact

Jason Socrates Bardi
jbardi@aip.org
240-535-4954

 @jasonbardi

http://www.aip.org 

Jason Socrates Bardi | EurekAlert!

More articles from Physics and Astronomy:

nachricht Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>