TY - GEN

T1 - Optical metrology for nanowires grown with molecular beam epitaxy

AU - Møller Madsen, Jonas Skovlund

AU - Jensen, Søren Alkærsig

AU - Kanne, Thomas

AU - Nygard, Jesper

AU - Hansen, Poul Erik

N1 - Publisher Copyright: © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

PY - 2020

Y1 - 2020

N2 - Semiconductor nanowires are important materials for quantum transport experiments and are used in research on qubits. Extended arrays of nanowires can be grown bottom-up by Molecular Beam Epitaxy (MBE). The full process involves several steps. When fabricating nanowires, a common practice is to follow a well-established recipe and only characterize the finalized materials. If the final wires are found to be flawed, the process must be repeated with new parameters. It is therefore desirable to have a characterization method to monitor the process before and after each fabrication step. Conventional characterization techniques such as SEM are time-consuming and, in some cases, damage the samples, e.g. before and after an electron beam lithography process. Scatterometry is fast, accurate, non-destructive and is already used in the semiconductor industry. In this work, it is demonstrated that the imaging scatterometry technique is capable of monitoring the MBE fabrication process of InAs-nanowire arrays during the different process steps. Relevant parameters such as thin film thickness, hole depth, and diameter, etc., are found with nm precision for a macroscopic area in a few minutes. Using this approach, we demonstrate that errors can be caught early in the process and ultimately save resources while assuring a high quality of the final material.

AB - Semiconductor nanowires are important materials for quantum transport experiments and are used in research on qubits. Extended arrays of nanowires can be grown bottom-up by Molecular Beam Epitaxy (MBE). The full process involves several steps. When fabricating nanowires, a common practice is to follow a well-established recipe and only characterize the finalized materials. If the final wires are found to be flawed, the process must be repeated with new parameters. It is therefore desirable to have a characterization method to monitor the process before and after each fabrication step. Conventional characterization techniques such as SEM are time-consuming and, in some cases, damage the samples, e.g. before and after an electron beam lithography process. Scatterometry is fast, accurate, non-destructive and is already used in the semiconductor industry. In this work, it is demonstrated that the imaging scatterometry technique is capable of monitoring the MBE fabrication process of InAs-nanowire arrays during the different process steps. Relevant parameters such as thin film thickness, hole depth, and diameter, etc., are found with nm precision for a macroscopic area in a few minutes. Using this approach, we demonstrate that errors can be caught early in the process and ultimately save resources while assuring a high quality of the final material.

KW - Metrology

KW - Molecular Beam Epitaxy

KW - Nanowires

KW - Scatterometry

UR - http://www.scopus.com/inward/record.url?scp=85084171161&partnerID=8YFLogxK

U2 - 10.1117/12.2553680

DO - 10.1117/12.2553680

M3 - Article in proceedings

AN - SCOPUS:85084171161

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Quantum Dots, Nanostructures, and Quantum Materials

A2 - Huffaker, Diana L.

A2 - Eisele, Holger

PB - SPIE - International Society for Optical Engineering

T2 - Quantum Dots, Nanostructures, and Quantum Materials: Growth, Characterization, and Modeling XVII 2020

Y2 - 5 February 2020

ER -