Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIST Team Reports Method to Characterize New Insulating Materials for Microelectronics

27.08.2002


Advance Should Speed Semiconductor Industry Search



Researchers from the Commerce Department’s National Institute of Standards and Technology (NIST) reported today they have developed methods for characterizing key structural features of porous films being eyed as insulators for the ultrathin metal wires that will connect millions of devices on future microprocessors and increase processor speed. The advance, reported today at the American Chemical Society’s national meeting in Boston, will help semiconductor manufacturers and their materials suppliers home in on the most promising "nanoporous film" candidates for shielding miles of interconnecting wire on next-generation microprocessors.

Microprocessors, or central processing units, are both the "brains" and "engines" of computers and other microelectronic devices.


To increase processor speed, semiconductor manufacturers seek to reduce chip sizes. However, size reduction introduces problems with electrical interference between circuit elements ("cross-talk"), motivating development of better insulating materials. Current insulating materials such as silicon dioxide and fluorinated silicate glass (FSG) are approaching their limits as devices are squeezed ever closer on a chip.

To prepare better insulating films, many materials suppliers are developing films interspersed with very small holes that measure about 5 nanometers (billionths of a meter) in diameter or less. Introducing nanometer-sized air bubbles lowers a material’s dielectric constant, or "k" value-a measure of insulating performance. Air, the ideal insulator, has a dielectric constant of 1. Silicon dioxide and FSG, in contrast, have values of about 4.2 and 3.7, respectively.

For several years, the NIST team has been performing a variety of measurements to help the semiconductor industry characterize potential nanoporous insulators. Working with the NIST Center for Neutron Research, materials scientists Ronald Hedden, Barry Bauer, and Hae-Jeong Lee of the NIST Polymers Division developed a neutron scattering technique for surveying minuscule holes in film samples supplied by International SEMATECH, the consortium of chipmakers. Combined with information gathered with other methods, neutron scattering measurements reveal the size and volume fraction of pores, the connectivity among pores and the density of the underlying matrix.

The "Swiss cheese" approach to developing new insulators presents some formidable challenges. To be sure, riddling a material with tiny holes (or bubbles) lowers its "k" value, but changes other important properties as well. Also to be taken into account, for example, are a candidate material’s strength and hardness, how well it adheres to different substrates, and whether it can withstand high temperatures and etch chemicals during processing.

"An ideal replacement for silicon dioxide would provide the desired level of insulation without compromising barrier properties," explains Bauer. "The more fully we can characterize the pore structure and properties of these nanoporous materials, the more straightforward the search becomes."

Bauer, Hedden and Lee led an effort to extend contrast matching-a neutron-based technique for studying bulk materials-to nanoporous thin films. They succeeded by pumping solvent vapor mixtures into a special flow-through chamber containing the films. The vapor condenses into the pores, permitting neutron scattering measurements that probe the film density while yielding valuable information about pore connectivity. The new neutron technique also can detect nanometer-sized inhomogeneities in the composition of the matrix.

Though the results are promising, the contrast-matching procedure is time-consuming, taking three to four days per sample. One goal of the team is to develop a simpler alternative that industry could use to character films faster and more cheaply. Hedden says neutron scattering measurements could be used as a benchmark to evaluate data gathered with other approaches.

As a non-regulatory agency of the U.S. Department of Commerce’s Technology Administration, NIST develops and promotes measurements, standards and technology to enhance productivity, facilitate trade and improve the quality of life. For more information on NIST, visit www.nist.gov.

Mark Bello | EurekAlert!

More articles from Power and Electrical Engineering:

nachricht Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Solar-to-fuel system recycles CO2 to make ethanol and ethylene
19.09.2017 | DOE/Lawrence Berkeley National Laboratory

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>