Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > New method monitors semiconductor etching as it happens – with light

Photo by Chris Edwards, Amir Arbabi, Gabriel Popescu, and Lynford Goddard

A three-dimensional image of an etched gallium-arsenide semiconductor, taken during etching with a new microscopy technique that monitors the etching process on the nanometer scale. The height difference between the orange and purple regions is approximately 250 nanometers.
Photo by Chris Edwards, Amir Arbabi, Gabriel Popescu, and Lynford Goddard

A three-dimensional image of an etched gallium-arsenide semiconductor, taken during etching with a new microscopy technique that monitors the etching process on the nanometer scale. The height difference between the orange and purple regions is approximately 250 nanometers.

Abstract:
University of Illinois researchers have a new low-cost method to carve delicate features onto semiconductor wafers using light - and watch as it happens.

New method monitors semiconductor etching as it happens – with light

Champaign, IL | Posted on September 29th, 2012

"You can use light to image the topography and you can use light to sculpture the topography," said electrical and computer engineering professor Gabriel Popescu. "It could change the future of semiconductor etching."

Chip makers and semiconductor researchers need to very precisely control the dimensions of their devices. The dimensions of the components affect performance, speed, error rate and time to failure.

Semiconductors are commonly shaped by etching with chemicals. Etching errors, such as residual layers, can affect the ability to further process and etch as well as hamper device performance. Thus, researchers use time-consuming and costly processes to ensure precise etching - for some applications, to within a scant few nanometers.

The Illinois researchers' new technique can monitor a semiconductor's surface as it is etched, in real time, with nanometer resolution. It uses a special type of microscope that uses two beams of light to very precisely measure topography.

"The idea is that the height of the structure can be determined as the light reflects off the different surfaces," said electrical and computer engineering professor Lynford Goddard, who co-led the group with Popescu. "Looking at the change in height, you figure out the etch rate. What this allows us to do is monitor it while it's etching. It allows us to figure out the etch rate both across time and across space, because we can determine the rate at every location within the semiconductor wafer that's in our field of view."

The new method is faster, lower in cost, and less noisy than the widely used methods of atomic force microscopy or scanning tunneling microscopy, which cannot monitor etching in progress but only compare before and after measurements. In addition, the new method is purely optical, so there's no contact with the semiconductor surface and the researchers can monitor the whole wafer at once instead of point-by-point.

"I would say the main advantage of our optical technique is that it requires no contact," Popescu said. "We're just sending light, reflected off the sample, as opposed to an AFM where you need to come with a probe close to the sample."

In addition to monitoring the etching process, the light catalyzes the etching process itself, called photochemical etching. Traditional chemical etching creates features in steps or plateaus. For curved surfaces or other shapes, semiconductor researchers use photochemical etching. Usually, light shines though very expensive glass plates called masks that have distinct patterns of gray to let light through by degrees. A researcher must purchase or make a mask for each tweak of a pattern until the correct pattern of features is achieved.

By contrast, the new method uses a projector to shine a grayscale image onto the sample being etched. This allows the researchers to create complex patterns quickly and easily, and adjust them as needed.

"To create each mask is very expensive. That's impractical for research," Goddard said. "Because our technique is controlled by the computer, it can be dynamic. So you can start off etching one particular shape, midway through realize that you want to make some change, and then change the projector pattern to get the desired outcome."

The researchers envision this technology applied beyond etching, to real-time monitoring of other processes in materials science and life science - for example, watching carbon nanotubes self-assemble, or error monitoring during large-scale computer chip manufacturing. It could help chip manufacturers reduce costs and processing time by ensuring that equipment stays calibrated.

The National Science Foundation supported this work, published Sept. 28 in the journal Light: Science and Applications. Goddard and Popescu are also affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I.

Graduate students Chris Edwards and Amir Arbabi were also co-authors of the paper.

####

For more information, please click here

Contacts:
Liz Ahlberg
Physical Sciences Editor
217-244-1073


Lynford Goddard
217-244-0799


To reach
Gabriel Popescu
217-333-4840

Copyright © University of Illinois at Urbana-Champaign

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 Links

The paper, “Optically Monitoring and Controlling Nanoscale Topography During Semiconductor Etching,” is available online:

Beckman Institute for Advanced Science and Technology at the U. of I.:

Related News Press

News and information

CubeSat Structures Competition Opens Space Design to Students of the World December 16th, 2017

Record high photoconductivity for new metal-organic framework material December 15th, 2017

Error-free into the quantum computer age December 15th, 2017

Leti Will Demonstrate First 3D Anti-Crash Solution for Embedding in Drones: Fitted on a Mass-Market Microcontroller, 360Fusion Software Technology Detects any Dynamic Obstacle and Helps Guide Drones Away from Collisions December 15th, 2017

Videos/Movies

Quantum memory with record-breaking capacity based on laser-cooled atoms December 15th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Synthetic protein packages its own genetic material and evolves computationally designed protein assemblies are advancing research in synthetic life and in targeted drug delivery December 15th, 2017

Sandia researchers make solid ground toward better lithium-ion battery interfaces: Reducing the traffic jam in batteries December 13th, 2017

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

Chip Technology

Error-free into the quantum computer age December 15th, 2017

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

UCLA chemists synthesize narrow ribbons of graphene using only light and heat: Tiny structures could be next-generation solution for smaller electronic devices December 8th, 2017

Device makes power conversion more efficient: New design could dramatically cut energy waste in electric vehicles, data centers, and the power grid December 8th, 2017

Self Assembly

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

Nanotubes that build themselves April 14th, 2017

Nanocages for gold particles: what is happening inside? March 16th, 2017

Nanotubes/Buckyballs/Fullerenes/Nanorods

Scientists make transparent materials absorb light December 1st, 2017

Researchers advance technique to detect ovarian cancer: Rice, MD Anderson use fluorescent carbon nanotube probes to achieve first in vivo success November 30th, 2017

NanoSummit in Luxembourg: single wall carbon nanotubes have entered our lives as we approach a nanoaugmented future November 23rd, 2017

Fine felted nanotubes : Research team of Kiel University develops new composite material made of carbon nanotubes November 22nd, 2017

Discoveries

Quantum memory with record-breaking capacity based on laser-cooled atoms December 15th, 2017

Record high photoconductivity for new metal-organic framework material December 15th, 2017

Error-free into the quantum computer age December 15th, 2017

Synthetic protein packages its own genetic material and evolves computationally designed protein assemblies are advancing research in synthetic life and in targeted drug delivery December 15th, 2017

Announcements

CubeSat Structures Competition Opens Space Design to Students of the World December 16th, 2017

Record high photoconductivity for new metal-organic framework material December 15th, 2017

Error-free into the quantum computer age December 15th, 2017

Leti Will Demonstrate First 3D Anti-Crash Solution for Embedding in Drones: Fitted on a Mass-Market Microcontroller, 360Fusion Software Technology Detects any Dynamic Obstacle and Helps Guide Drones Away from Collisions December 15th, 2017

Tools

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

Untangling DNA: Researchers filter the entropy out of nanopore measurements December 8th, 2017

JPK Instruments announce partnership with Swiss company, Cytosurge AG. The partnership makes Cytosurge’s FluidFM® technology available on the JPK NanoWizard® AFM platform December 8th, 2017

Researchers advance technique to detect ovarian cancer: Rice, MD Anderson use fluorescent carbon nanotube probes to achieve first in vivo success November 30th, 2017

Industrial

A new product to help combat mouldy walls, thanks to technology developed at the ICN2 December 14th, 2017

Silicon Sense first to achieve EPA approval to import detonation nanodiamonds to US: Nanodiamond additives can significantly improve the performance of metal finishing, polymer thermal and mechanical compounds, polymer coatings, CMP polishing and a range of other applications November 29th, 2017

A new way to mix oil and water: Condensation-based method developed at MIT could create stable nanoscale emulsions November 8th, 2017

Researchers greenlight gas detection at room temperature October 26th, 2017

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