Researchers find a crucial difficulty in semiconductor device scaling

Sep 06, 2007
Dopants Revealed
Distribution of dopants revealed by atom probe. Credit: © Imago Scientific Instruments

In 1959, Nobel Prize winner Richard Feynman presented a talk entitled "There's Plenty of Room at the Bottom." Feynman concluded that there was no physical reason why humans couldn't manipulate atoms. However, if atomic manipulation is achieved the question of observing the new atom positions remains. How do you know what you have done?

As reported in the Sept. 7, 2007 issue of Science, IBM and Imago have taken a seminal step along the path to achieving Dr. Feynman’s vision by observing, for the first time, distributions of individual dopant atoms in semiconductor devices.

Atom probe tomography was used to quantify the location and elemental identity of the atoms proximate to defects in silicon. The dopants were implanted into the silicon uniformly and it was always hoped that the distribution of dopant atoms would be uniform.

However, the IBM and Imago researchers found that clusters (more properly Cottrell atmospheres) of dopant atoms form around defects after ion implantation and annealing. Furthermore, these atmospheres persist in surrounding dislocation loops even after considerable thermal treatment creating dopant fluctuations that may ultimately limit the scalability of semiconductor devices.

“This is the first time that unambiguous quantitative 3D information regarding the precise location of individual dopant atoms relative to defects has been available” said study co-author and Imago CEO Tom Kelly. “The ability of the Imago LEAP 3000X Si laser assisted atom probe to make this measurement is the fruition of many years of instrumentation and applications development. We now have a powerful new way to probe the atomic positions of dopants in a semiconductor device. This is a critical tool for scientists seeking to answer Professor Feynman’s challenge to manipulate matter at the atomic level and hence enable nanotechnology.”

Previously, researchers have used secondary ion mass spectrometry (SIMS) and transmission electron microscopy (TEM) to correlate indirectly the presence of dopant atoms with the evolution of defects, and detailed models have been proposed to account for these experimental correlations. However, the atom probe study published in Science reports, for the first time, the location of individual dopant atoms. Said Imago Senior Director of Applications and co-author David Larson, “The Sept. 7 Science article is the most recent in a series of significant scientific advances reported by Imago’s customers.” Added Dr. Larson, “In addition to producing breakthrough published scientific results, the Imago atom probe is also being applied to various industrial problems. These proprietary results are advancing scientific knowledge, enabling the development of new products, and improving time to market for our customers.”

Source: Imago Scientific Instruments

Explore further: Renesas announces SRAM using leading-edge 16 nm FinFET for automotive information systems

add to favorites email to friend print save as pdf

Related Stories

Engineers chart semiconductors on the scale of atoms

Aug 01, 2005

Spanning fewer than a thousand atoms, the electronic devices on semiconductor chips have become so miniscule they defy most efforts to characterize them. Now for the first time, engineers have demonstrated a way to image ...

Recommended for you

Cyclist's helmet, Volvo car to communicate for safety

14 hours ago

Volvo calls it "a wearable life-saving wearable cycling tech concept." The car maker is referring to a connected car and helmet prototype that enables two-way communication between Volvo drivers and cyclists ...

California puzzles over safety of driverless cars

15 hours ago

California's Department of Motor Vehicles will miss a year-end deadline to adopt new rules for cars of the future because regulators first have to figure out how they'll know whether "driverless" vehicles ...

Britain's UKIP issues online rules after gaffes

15 hours ago

UK Independence Party (UKIP), the British anti-European Union party, has ordered a crackdown on the use of social media by supporters and members following a series of controversies.

Sony saga blends foreign intrigue, star wattage

15 hours ago

The hackers who hit Sony Pictures Entertainment days before Thanksgiving crippled the network, stole gigabytes of data and spilled into public view unreleased films and reams of private and sometimes embarrassing ...

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.