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Ek M, Lehmann S, Wallenberg R. Electron channelling: challenges and opportunities for compositional analysis of nanowires by TEM. NANOTECHNOLOGY 2020; 31:364005. [PMID: 32454471 DOI: 10.1088/1361-6528/ab9679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Energy dispersive x-ray spectroscopy in a transmission electron microscope is often the first method employed to characterize the composition of nanowires. Ideally, it should be accurate and sensitive down to fractions of an atomic percent, and quantification results are often reported as such. However, one can often get substantial errors in accuracy even though the precision is high: for nanowires it is common for the quantified V/III atomic ratios to differ noticeably from 1. Here we analyse the origin of this systematic error in accuracy for quantification of the composition of III-V nanowires. By varying the electron illumination direction, we find electron channelling to be the primary cause, being responsible for errors in quantified V/III atomic ratio of 50%. Knowing the source of the systematic errors is required for applying appropriate corrections. Lastly, we show how channelling effects can provide information on the crystallographic position of dopants.
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Affiliation(s)
- M Ek
- Centre for Analysis and Synthesis, Lund University, Box 124, Lund 22100, Sweden. NanoLund, Lund University, Box 118, Lund 22100, Sweden
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Cooper D, Bernier N, Rouvière JL, Wang YY, Weng W, Madan A, Mochizuki S, Jagannathan H. High-precision deformation mapping in finFET transistors with two nanometre spatial resolution by precession electron diffraction. APPLIED PHYSICS LETTERS 2017; 110:223109. [PMID: 28652641 PMCID: PMC5453792 DOI: 10.1063/1.4983124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 04/25/2017] [Indexed: 06/07/2023]
Abstract
Precession electron diffraction has been used to systematically measure the deformation in Si/SiGe blanket films and patterned finFET test structures grown on silicon-on-insulator type wafers. Deformation maps have been obtained with a spatial resolution of 2.0 nm and a precision of ±0.025%. The measured deformation by precession diffraction for the blanket films has been validated by comparison to energy dispersive x-ray spectrometry, X-Ray diffraction, and finite element simulations. We show that although the blanket films remain biaxially strained, the patterned fin structures are fully relaxed in the crystallographic planes that have been investigated. We demonstrate that precession diffraction is a viable deformation mapping technique that can be used to provide useful studies of state-of-the-art electronic devices.
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Affiliation(s)
- David Cooper
- University Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble, France
| | - Nicolas Bernier
- University Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble, France
| | - Jean-Luc Rouvière
- University Grenoble Alpes, F-38000 Grenoble, France and CEA, INAC, MINATEC Campus, F-38054 Grenoble, France
| | - Yun-Yu Wang
- IBM Microelectronics, 2070 Route 52, Hopewell Junction, New York 12533, USA
| | - Weihao Weng
- IBM Microelectronics, 2070 Route 52, Hopewell Junction, New York 12533, USA
| | - Anita Madan
- IBM Microelectronics, 2070 Route 52, Hopewell Junction, New York 12533, USA
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High-resolution scanning precession electron diffraction: Alignment and spatial resolution. Ultramicroscopy 2017; 174:79-88. [DOI: 10.1016/j.ultramic.2016.12.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/23/2016] [Accepted: 12/24/2016] [Indexed: 11/24/2022]
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Lugg N, Kothleitner G, Shibata N, Ikuhara Y. On the quantitativeness of EDS STEM. Ultramicroscopy 2015; 151:150-159. [DOI: 10.1016/j.ultramic.2014.11.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/22/2014] [Accepted: 11/24/2014] [Indexed: 10/24/2022]
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