Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Viewing atomic structures of dopant atoms in 3-D relating to electrical activity in a semiconductor

Soft X-rays excite the core level electrons, leading to the emission of photoelectrons from various atoms, whose waves are then scattered by the surrounding atoms. The interference pattern between the scattered and direct photoelectron waves creates the photoelectron hologram, which may then be captured with an electron analyzer.
CREDIT
Nano Letters
Soft X-rays excite the core level electrons, leading to the emission of photoelectrons from various atoms, whose waves are then scattered by the surrounding atoms. The interference pattern between the scattered and direct photoelectron waves creates the photoelectron hologram, which may then be captured with an electron analyzer. CREDIT Nano Letters

Abstract:
Scientists at Tokyo Institute of Technology (Tokyo Tech) and their research team involving researchers of JASRI, Osaka University, Nagoya Institute of Technology, and Nara Institute of Science and Technology have just developed a novel approach to determine and visualize the three-dimensional (3D) structure of individual dopant atoms using SPring-8. The technique will help improve the current understanding of the atomic structures of dopants in semiconductors correlated with their electrical activity and thus help support the development of new manufacturing processes for high-performance devices.

Viewing atomic structures of dopant atoms in 3-D relating to electrical activity in a semiconductor

Tokyo, Japan | Posted on December 28th, 2017

Using a combination of spectro-photoelectron holography, electrical property measurements, and first-principles dynamics simulations, the 3D atomic structures of dopant impurities in a semiconductor crystal were successfully revealed. The need for a better understanding of the atomic structures of dopants in semiconductors had been long felt, mainly because the current limitations on active dopant concentrations result from the deactivation of excess dopant atoms by the formation of various types of clusters and other defect structures.

The search for techniques to electrically activate the dopant impurities in semiconductors with high efficiency and/or at high concentrations have always been an essential aspect of semiconductor device technology. However, despite various successful developments, the achievable maximum concentration of active dopants remains limited. Given the impact of the dopant atomic structures in this process, these structures had been previously investigated using both theoretical and experimental approaches. However, direct observation of the 3D structures of the dopant atomic arrangements had hitherto been difficult to achieve.

In this study, Kazuo Tsutsui at Tokyo Tech and colleagues involving researchers at JASRI, Osaka University, Nagoya Institute of Technology, and Nara Institute of Science and Technology developed spectro-photoelectron holography using SPring-8, and leveraged the capabilities of photoelectron holography in determining the concentrations of dopants at different sites, based on the peak intensities of the photoelectron spectrum, and classified electrically active / inactive atomic sites. These structures directly related with the density of carriers. In this approach, soft X-ray excitation of the core level electrons leads to the emission of photoelectrons from various atoms, whose waves are then scattered by the surrounding atoms. The resulting interference pattern creates the photoelectron hologram, which may then be captured with an electron analyzer. The photoelectron spectra acquired in this manner contain information from more than one atomic site. Therefore, peak fitting is performed to obtain the photoelectron hologram of individual atomic sites. The combination of this technique with first-principles simulations allows the successful estimation of the 3D structure of the dopant atoms, and the assessment of their different chemical bonding states. The method was used to estimate the 3D structures of arsenic atoms doped onto a silicon surface. The obtained results fully demonstrated the power of the proposed method and allowed confirmation of several previous results.

This work demonstrates the potential of spectro-photoelectron holography for the analysis of impurities in semiconductors. This technique allows analyses that are difficult to perform with conventional approaches and should therefore be useful in the development of improved doping techniques and, ultimately, in supporting the manufacture of high-performance devices.

####

About Tokyo Institute of Technology
Tokyo Institute of Technology stands at the forefront of research and higher education as the leading university for science and technology in Japan. Tokyo Tech researchers excel in a variety of fields, such as material science, biology, computer science and physics. Founded in 1881, Tokyo Tech has grown to host 10,000 undergraduate and graduate students who become principled leaders of their fields and some of the most sought-after scientists and engineers at top companies. Embodying the Japanese philosophy of "monotsukuri," meaning technical ingenuity and innovation, the Tokyo Tech community strives to make significant contributions to society through high-impact research.
Website: http://www.titech.ac.jp/english/

SPring-8

The name "SPring-8" comes from "Super Photon ring-8 GeV". It is owned by RIKEN and located in Harima Science Garden City, Hyogo Prefecture, Japan. SPring-8 generates the world's highest-performance synchrotron radiation and was opened in 1997 to users from universities, research institutes, and companies. Synchrotron radiation is an electromagnetic wave that is produced when electron beams, accelerated to nearly the speed of light, are bent in a high magnetic field. High-intensity synchrotron radiation in a wide range of energy from infrared to soft and hard X-ray regions is available at SPring-8.

About Osaka University

Osaka University was founded in 1931 as one of the seven imperial universities of Japan and now has expanded to one of Japan's leading comprehensive universities.?The University has now embarked on open research revolution from a position as Japan's most innovative university and among the most innovative institutions in the world according to Reuters 2015 Top 100 Innovative Universities and the Nature Index Innovation 2017. The university's ability to innovate from the stage of fundamental research through the creation of useful technology with economic impact stems from its broad disciplinary spectrum.
Website: http://resou.osaka-u.ac.jp/en/top

About NAIST

NAIST was founded in 1991 as a Japanese national university consisting solely of graduate schools in three integrated areas: information science, biological sciences, and materials science. In the early 2018, NAIST will transform its current structure into the one graduate school system to further promote the mission of cultivating global leaders in science and technology who will actively respond to social demands. At present, about 1,000 students -22% from overseas- are supervised by roughly 200 NAIST faculty. With its cutting-edge facilities and a 5 to 1 student-to-faculty ratio, NAIST's world-leading research and education are a direct result of its rich, global environment and supportive infrastructure. NAIST has quickly established itself as a world-class research and education center where young scientists and technologists become tomorrow's global leaders. For more detail please visit: http://www.naist.jp/en/

For more information, please click here

Contacts:
Emiko Kawaguchi

81-357-342-975

Copyright © Tokyo Institute of Technology

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

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 5, 2019 January 18th, 2019

ULVAC Inc., and Oxford Instruments Plasma Technology collaborate to bring Atomic Scale Processing solutions to the Japanese Power and RF markets January 18th, 2019

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Brilliant glow of paint-on semiconductors comes from ornate quantum physics January 18th, 2019

Imaging

Chirality in 'real-time' January 14th, 2019

DNA design that anyone can do: Computer program can translate a free-form 2-D drawing into a DNA structure January 4th, 2019

Using sound to independently levitate a range of objects is achieved for the first time December 28th, 2018

Scientists use magnetic defects to achieve electromagnetic wave breakthrough December 20th, 2018

Possible Futures

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Brilliant glow of paint-on semiconductors comes from ornate quantum physics January 18th, 2019

Nanobiotix Plans to Conduct Registered Public Offering in the United States January 17th, 2019

Power stations driven by light: More efficient solar cells imitate photosynthesis January 16th, 2019

Chip Technology

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 5, 2019 January 18th, 2019

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Brilliant glow of paint-on semiconductors comes from ornate quantum physics January 18th, 2019

January 18th, 2019

Nanoelectronics

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Study on low noise, high-performance transistors may bring innovations in electronics December 28th, 2018

The feature size and functional range of molecular electronic devices: Monitoring the transition from tunneling leakage current to molecular tunneling December 16th, 2018

2-D magnetism: Atom-thick platforms for energy, information and computing research: Scientists say the tiny 'spins' of electrons show potential to one day support next-generation innovations in many fields October 31st, 2018

Discoveries

Using bacteria to create a water filter that kills bacteria: New technology can clean water twice as fast as commercially available ultrafiltration membranes January 18th, 2019

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Brilliant glow of paint-on semiconductors comes from ornate quantum physics January 18th, 2019

January 18th, 2019

Announcements

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 5, 2019 January 18th, 2019

ULVAC Inc., and Oxford Instruments Plasma Technology collaborate to bring Atomic Scale Processing solutions to the Japanese Power and RF markets January 18th, 2019

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Brilliant glow of paint-on semiconductors comes from ornate quantum physics January 18th, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Using bacteria to create a water filter that kills bacteria: New technology can clean water twice as fast as commercially available ultrafiltration membranes January 18th, 2019

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Brilliant glow of paint-on semiconductors comes from ornate quantum physics January 18th, 2019

New materials could help improve the performance of perovskite solar cells January 11th, 2019

Tools

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 5, 2019 January 18th, 2019

ULVAC Inc., and Oxford Instruments Plasma Technology collaborate to bring Atomic Scale Processing solutions to the Japanese Power and RF markets January 18th, 2019

Drilling speed increased by 20% yet another upgrade in the oil & gas sector made possible by graphene nanotubes January 15th, 2019

Chirality in 'real-time' January 14th, 2019

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project