Researchers reveal insights on silicon semiconductors

Jun 23, 2006
7x7 Si (111) reconstruction
7x7 Si (111) reconstruction

"Smaller. Faster. Wildly complex." This could easily be the motto for semiconductors-the materials that, among lots of other advances in electronics, allow cell phones to continuously shrink in size while increasing the number of their mind-boggling functions.

While exceptionally tiny, semiconductors possess the ability to enable a multitude of complex functions, making them an invaluable ingredient in electronics technology. But, while the computer age is in full bloom, knowledge of semiconductor nanostructures is still relatively young; and research seeking to answer essential and sometimes-basic materials questions is occurring at breakneck speed.

As part of this race to understand semiconductors better, a team of researchers from the University of Wisconsin-Madison has revealed valuable information about silicon and it's surface structure. In particular, the researchers, who did much of their work at the Synchrotron Radiation Center, examined the inimitable 7 x 7 surface structure of Si(111), the most stable surface of silicon.

"Surfaces and interfaces dominate in today's silicon devices, since the surface to volume ratio goes up in small structures. These two-dimensional structures are difficult to study, and the SRC work explores an aspect that has remained unexplored on semiconductors so far," says physicist Ingo Barke, who, along with UW-Madison collaborators, published results in a June 2006 issue of Physical Review Letters.

"Our results reveal a very unusual surface band structure, which can be best explained by a mechanism called 'electron-phonon interaction,'" Barke continues. "Phonons are vibrations of the atoms, which are surrounded by electrons. By shaking the surface atoms the orbiting electrons 'feel' these vibrations and change their movement in a characteristic way. Our work connects two intensively studied fields: electron-phonon interaction which causes conventional superconductivity, and semiconductor surfaces which are of great importance for electronic devices and semiconductor technology."

While similar research has been done on metal surfaces, the current study is the first example of such examination on a semiconductor surface. History has shown that these interesting jumps in basic knowledge about materials such as semiconductors can have significant practical impacts down the road-and this is particularly true in the case of silicon, which itself has become so inextricably important in modern society that it is credited with its own "silicon age."

"Electron-phonon interaction itself is of great scientific and practical interest because it is the key mechanism for conventional superconductivity," Barke notes, adding that the ultimate goal lies in the possibility of tailoring materials for a new generation of "designer superconductors."

Source: University of Wisconsin

Explore further: New research predicts when, how materials will act

add to favorites email to friend print save as pdf

Related Stories

Researchers build atomically thin gas and chemical sensors

Feb 19, 2015

The relatively recent discovery of graphene, a two-dimensional layered material with unusual and attractive electronic, optical and thermal properties, led scientists to search for other atomically thin materials ...

Skin device uses motion to power electronics

Jan 29, 2015

Can a skin patch power wearables? Skin-based generators have become an area of focus among researchers working on how to scavenge muscle motion whereby skin becomes a charge-collector. A detailed report in ...

The future of electronics—now in 2-D

Feb 14, 2015

The future of electronics could lie in a material from its past, as researchers from The Ohio State University work to turn germanium—the material of 1940s transistors—into a potential replacement for silicon.

Recommended for you

New filter could advance terahertz data transmission

11 hours ago

University of Utah engineers have discovered a new approach for designing filters capable of separating different frequencies in the terahertz spectrum, the next generation of communications bandwidth that ...

The super-resolution revolution

11 hours ago

Cambridge scientists are part of a resolution revolution. Building powerful instruments that shatter the physical limits of optical microscopy, they are beginning to watch molecular processes as they happen, ...

Precision gas sensor could fit on a chip

13 hours ago

Using their expertise in silicon optics, Cornell engineers have miniaturized a light source in the elusive mid-infrared (mid-IR) spectrum, effectively squeezing the capabilities of a large, tabletop laser onto a 1-millimeter ...

A new X-ray microscope for nanoscale imaging

14 hours ago

Delivering the capability to image nanostructures and chemical reactions down to nanometer resolution requires a new class of x-ray microscope that can perform precision microscopy experiments using ultra-bright ...

New research signals big future for quantum radar

Feb 26, 2015

A prototype quantum radar that has the potential to detect objects which are invisible to conventional systems has been developed by an international research team led by a quantum information scientist at the University ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.