Research dishes out flexible computer chips

Jul 18, 2006
Research dishes out flexible computer chips
UW-Madison electrical and computer engineering graduate student Hao-Chih Yuan holds a sample of a semiconductor film on plastic.

New thin-film semiconductor techniques invented by University of Wisconsin-Madison engineers promise to add sensing, computing and imaging capability to an amazing array of materials.

Historically, the semiconductor industry has relied on flat, two-dimensional chips upon which to grow and etch the thin films of material that become electronic circuits for computers and other electronic devices. But as thin as those chips might seem, they are quite beefy in comparison to the result of a new UW-Madison semiconductor fabrication process detailed in the current issue of the Journal of Applied Physics.

A team led by electrical and computer engineer Zhenqiang (Jack) Ma and materials scientist Max Lagally have developed a process to remove a single-crystal film of semiconductor from the substrate on which it is built. This thin layer (only a couple of hundred nanometers thick) can be transferred to glass, plastic or other flexible materials, opening a wide range of possibilities for flexible electronics. In addition, the semiconductor film can be flipped as it is transferred to its new substrate, making its other side available for more components. This doubles the possible number of devices that can be placed on the film.

By repeating the process, layers of double-sided, thin-film semiconductors can be stacked together, creating powerful, low-power, three-dimensional electronic devices.

"It's important to note that these are single-crystal films of strained silicon or silicon germanium," says Ma. "Strain is introduced in the way we form the membrane. Introducing strain changes the arrangement of atoms in the crystal such that we can achieve much faster device speed while consuming less power."

For non-computer applications, flexible electronics are beginning to have significant impact. Solar cells, smart cards, radio frequency identification (RFID) tags, medical applications, and active-matrix flat panel displays could all benefit from the development. The techniques could allow flexible semiconductors to be embedded in fabric to create wearable electronics or computer monitors that roll up like a window shade.

"This is potentially a paradigm shift," says Lagally. "The ability to create fast, low-power, multilayer electronics has many exciting applications. Silicon germanium membranes are particularly interesting. Germanium has a much higher adsorption for light than silicon. By including the germanium without destroying the quality of the material, we can achieve devices with two to three orders of magnitude more sensitivity."

That increased sensitivity could be applied to create superior low-light cameras, or smaller cameras with greater resolution.

Source: University of Wisconsin-Madison, by James Beal

Explore further: World's most complex crystal simulated

add to favorites email to friend print save as pdf

Related Stories

Thin-film hybrid oxide-organic microprocessor

Dec 10, 2014

Holst Centre, imec and their partner Evonik have realized a general-purpose 8-bit microprocessor, manufactured using complementary thin-film transistors (TFTs) processed at temperatures compatible with plastic ...

Extreme materials and ubiquitous electronics

Dec 03, 2014

Nearly everyone seems to carry a cell phone or tablet. But if Tomás Palacios' vision of the future of electronics comes to bear, it will be increasingly difficult to separate electronics from all the other ...

Nanotubes may restore sight to blind retinas

Dec 02, 2014

The aging process affects everything from cardiovascular function to memory to sexuality. Most worrisome for many, however, is the potential loss of eyesight due to retinal degeneration.

Recommended for you

Finding faster-than-light particles by weighing them

5 hours ago

In a new paper accepted by the journal Astroparticle Physics, Robert Ehrlich, a recently retired physicist from George Mason University, claims that the neutrino is very likely a tachyon or faster-than-light par ...

Controlling core switching in Pac-man disks

Dec 24, 2014

Magnetic vortices in thin films can encode information in the perpendicular magnetization pointing up or down relative to the vortex core. These binary states could be useful for non-volatile data storage ...

World's most complex crystal simulated

Dec 24, 2014

The most complicated crystal structure ever produced in a computer simulation has been achieved by researchers at the University of Michigan. They say the findings help demonstrate how complexity can emerge ...

Atoms queue up for quantum computer networks

Dec 24, 2014

In order to develop future quantum computer networks, it is necessary to hold a known number of atoms and read them without them disappearing. To do this, researchers from the Niels Bohr Institute have developed ...

New video supports radiation dosimetry audits

Dec 23, 2014

The National Physical Laboratory (NPL), working with the National Radiotherapy Trials Quality Assurance Group, has produced a video guide to support physicists participating in radiation dosimetry audits.

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.