Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

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

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

BBC World Service to broadcast Forum discussion on graphene July 6th, 2015

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Videos/Movies

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Freezing single atoms to absolute zero with microwaves brings quantum technology closer: Atoms frozen to absolute zero using microwaves July 2nd, 2015

Govt.-Legislation/Regulation/Funding/Policy

New technology using silver may hold key to electronics advances July 2nd, 2015

NIST Group Maps Distribution of Carbon Nanotubes in Composite Materials July 2nd, 2015

Influential Interfaces Lead to Advances in Organic Spintronics July 1st, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

Chip Technology

Nanometrics to Announce Second Quarter Financial Results on July 23, 2015 July 2nd, 2015

The quantum middle man July 2nd, 2015

New technology using silver may hold key to electronics advances July 2nd, 2015

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

Self Assembly

Groundbreaking research to help control liquids at micro and nano scales July 3rd, 2015

New conductive ink for electronic apparel June 25th, 2015

Giving atoms their marching orders: Highly homogeneous nanotube enforces single-file flow of atoms in gas diffusion. Direct comparison of single-file and Fickian diffusion possible with new system described by researchers at the University of South Carolina and University of Flor June 24th, 2015

n-tech Research Issues Report on Smart Coatings Market, Free Download Available on Firm’s Website June 24th, 2015

Nanotubes/Buckyballs/Fullerenes

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

Discovery of nanotubes offers new clues about cell-to-cell communication July 2nd, 2015

NIST Group Maps Distribution of Carbon Nanotubes in Composite Materials July 2nd, 2015

NIST ‘How-To’ Website Documents Procedures for Nano-EHS Research and Testing July 1st, 2015

Discoveries

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

New Biosensor Produced in Iran to Detect Effective Drugs in Cancer Treatment July 4th, 2015

Announcements

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

BBC World Service to broadcast Forum discussion on graphene July 6th, 2015

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Tools

A 'movie' of ultrafast rotating molecules at a hundred billion per second: A quantum wave-like nature was successfully observed in rotating nitrogen molecules July 4th, 2015

Clues to inner atomic life from subtle light-emission shifts: Hyperfine structure of light absorption by short-lived cadmium atom isotopes reveals characteristics of the nucleus that matter for high precision detection methods July 3rd, 2015

Nanometrics to Announce Second Quarter Financial Results on July 23, 2015 July 2nd, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

Industrial

Production of Zirconium Carbide Nanoparticles at Low Temperature without Thermal Operations July 5th, 2015

Iranian Scientists Find Simple, Economic Method to Synthesize Antibacterial Nanoparticles July 2nd, 2015

Green Chemistry Methods Used in Iran to Produce Zinc Oxide Nanoparticles June 27th, 2015

Stanford researchers stretch a thin crystal to get better solar cells June 25th, 2015

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