Atomic-scale characterization of germanium isotopic multilayers by atom probe tomography

Journal Article · Mon Jan 14 04:00:00 EST 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4773675· OSTI ID:22102215

Shimizu, Y.; Takamizawa, H.; Toyama, T.; Inoue, K.; Nagai, Y. ^[1]; Kawamura, Y.; Uematsu, M.; Itoh, K. M. ^[2]; Haller, E. E. ^[3]

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1. Oarai Center, Institute for Materials Research, Tohoku University, 2145-2 Narita, Oarai, Ibaraki 311-1313 (Japan)
2. School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)
3. University of California at Berkeley and Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

We report comparison of the interfacial sharpness characterization of germanium (Ge) isotopic multilayers between laser-assisted atom probe tomography (APT) and secondary ion mass spectrometry (SIMS). An alternating stack of 8-nm-thick naturally available Ge layers and 8-nm-thick isotopically enriched {sup 70}Ge layers was prepared on a Ge(100) substrate by molecular beam epitaxy. The APT mass spectra consist of clearly resolved peaks of five stable Ge isotopes ({sup 70}Ge, {sup 72}Ge, {sup 73}Ge, {sup 74}Ge, and {sup 76}Ge). The degree of intermixing at the interfaces between adjacent layers was determined by APT to be around 0.8 {+-} 0.1 nm which was much sharper than that obtained by SIMS.

• OSTI ID: 22102215
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 113; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
GERMANIUM
GERMANIUM 70
GERMANIUM 72
GERMANIUM 73
GERMANIUM 74
GERMANIUM 76
INTERFACES
ION MICROPROBE ANALYSIS
IONS
LASER RADIATION
LAYERS
MASS SPECTRA
MASS SPECTROSCOPY
MOLECULAR BEAM EPITAXY
SEMICONDUCTOR MATERIALS
SUBSTRATES
TOMOGRAPHY