Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nanomembranes promise new materials for advanced electronics

Abstract:
The camera in your phone collects light on silicon and translate that information into digital bits. One of the reasons those cameras and phones continue to improve is that researchers are developing new materials that absorb more light, use less power, and are less expensive to produce.

Nanomembranes promise new materials for advanced electronics

Madison, WI | Posted on July 21st, 2011

Now, University of Wisconsin-Madison materials science and engineering researchers have introduced innovations that could make possible a wide range of new crystalline materials. Writing in the June 8 web issue of the American Chemical Society journal ACS Nano, Research Assistants Deborah Paskiewicz and Boy Tanto along with Scientist Donald Savage and Erwin W. Mueller Professor and Bascom Professor of Surface Science Max Lagally, describe a new approach for using thin sheets of semiconductor known as nanomembranes.

Controlled stretching of these membranes via epitaxy allows the team to fabricate fully elastically relaxed silicon germanium nanomembranes for use as growth substrates for new materials. The team grew defect-free silicon germanium layers with any desired germanium concentration on silicon substrates and then released the silicon germanium layers from the rigid silicon, allowing them to relax completely as free-standing nanomaterials. The silicon germanium film is then transferred to a new host and bonded there. From this stage, a defect-free bulk silicon germanium crystal can be grown (something not possible with current technology), or the silicon germanium membrane can be used as a unique substrate to grow other materials.

Epitaxy, growth that controls the arrangement of atoms in thin layers on a substrate, is the fundamental technology underlying the semiconductor industry's use of these new materials. By combining elements, researchers can grow materials with unique properties that make possible new kinds of sensors or high speed, low-power, efficient advanced electronics. It is the ability to grow them without detrimental defects that makes these alloys useful to the semiconductor industry. However, making high-quality crystals that combine two or more elements faces significant limitations that have vexed researchers for decades.

"Many materials consisting of more than one element simply cannot be used. The distances between atoms are not the same," says Lagally. "When one begins to grow such a layer, the atoms start to interfere with each other and very soon the material no longer can grow as just one crystal because it starts to have defects in it. Eventually, it breaks up into small crystals and becomes polycrystalline, or even cracks."

In addition to its use in the semiconductor industry, silicon germanium is important to the nascent field of quantum computing. A quantum computer makes direct use of quantum mechanical phenomena such as superposition and entanglement to perform calculations. Current computers are limited to two states; on and off, or zero and one. With superposition, quantum computers encode information as quantum bits. These bits represent the varying states and inner workings of atoms and electrons. By manipulating these multiple states simultaneously, a large-scale quantum computer, if it can be built, could be millions of times more powerful than today's most powerful classical supercomputer.

"UW-Madison Physics Professor Mark Eriksson uses silicon germanium to make two-dimensional electron gases. A ‘two-dimensional electron gas' is a layer of a semiconductor in which charges are able to move freely over large distances, in analogy with atoms in a real gas, except confined to a thin layer and hence two-dimensional. For quantum computing, this 2-D electron gas is formed in a strained-silicon layer grown on a silicon germanium substrate. Electrodes put on top of a structure containing the 2-D electron gas in the strained-silicon layer allow one to move and control single electrons, turning regions of the quantum well into ‘electron buckets,' if you will, that are defined by the electric fields from the top electrodes,' says Lagally.

A major obstacle to developing a quantum computer is creating multiple quantum buckets as similar as possible. To make rapid progress, researchers need low-defect and consistent materials.

"With the silicon germanium substrates we have been using, the electrostatic fields can be quite uncertain because of the defects in the substrate," says Lagally. "We believe our new process can fix that. Because the substrate material is uniform, without defects, it should bring more predictability and control to Mark's efforts."

Beyond silicon germanium, Lagally says the process should work for a wide range of exotic materials that cannot be grown in bulk but have interesting properties. Materials Science and Engineering Associate Professor Paul Evans develops new ways to probe and apply these materials.

"The thin defect-free substrates that can be produced by transferring and relaxing these layers present exciting opportunities in the growth of materials beyond silicon and other traditional semiconductors," Evans says. "With this approach, it will be possible to produce defect-free substrates of materials for which no high-crystalline quality bulk materials exist. In complex oxides, this can lead to thin substrates that stabilize specific ferroelectric or dielectric phases. That could lead to better oscillators, sensors and optical devices, that are important to the cell phones, cameras and computers we use everyday."

This research is funded by the U.S. Department of Energy with facilities support by the National Science Foundation and the UW-Madison Materials Research Science and Engineering Center as well as the NSF Graduate Research Fellowship Program.

####

For more information, please click here

Contacts:
Jim Beal

College of Engineering
1415 Engineering Drive
Madison, WI 53706

Copyright © University of Wisconsin-Madison

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Deep Space Industries and SFL selected to provide satellites for HawkEye 360’s Pathfinder mission: The privately-funded space-based global wireless signal monitoring system will be developed by Deep Space Industries and UTIAS Space Flight Laboratory May 26th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Harnessing solar and wind energy in one device could power the 'Internet of Things' May 26th, 2016

Thermal modification of wood and a complex study of its properties by magnetic resonance May 26th, 2016

Chip Technology

Gigantic ultrafast spin currents: Scientists from TU Wien (Vienna) are proposing a new method for creating extremely strong spin currents. They are essential for spintronics, a technology that could replace today's electronics May 25th, 2016

Diamonds closer to becoming ideal semiconductors: Researchers find new method for doping single crystals of diamond May 25th, 2016

Dartmouth team creates new method to control quantum systems May 24th, 2016

Attosecond physics: A switch for light-wave electronics May 24th, 2016

Nanoelectronics

Researchers demonstrate size quantization of Dirac fermions in graphene: Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices May 20th, 2016

Graphene: A quantum of current - When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene May 20th, 2016

New type of graphene-based transistor will increase the clock speed of processors: Scientists have developed a new type of graphene-based transistor and using modeling they have demonstrated that it has ultralow power consumption compared with other similar transistor devices May 19th, 2016

Self-healing, flexible electronic material restores functions after many breaks May 17th, 2016

Discoveries

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Finding a new formula for concrete: Researchers look to bones and shells as blueprints for stronger, more durable concrete May 26th, 2016

Announcements

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Deep Space Industries and SFL selected to provide satellites for HawkEye 360’s Pathfinder mission: The privately-funded space-based global wireless signal monitoring system will be developed by Deep Space Industries and UTIAS Space Flight Laboratory May 26th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic