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Real-time extraction of growth rates from rotating substrates during molecular-beam epitaxy

Collins, D. A. and Papa, G. O. and McGill, T. C. (1995) Real-time extraction of growth rates from rotating substrates during molecular-beam epitaxy. Journal of Vacuum Science and Technology B, 13 (5). pp. 1953-1959. ISSN 1071-1023. doi:10.1116/1.588114.

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We present a method for measuring molecular‐beam epitaxy growth rates in near real‐time on rotating substrates. This is done by digitizing a video image of the reflection high‐energy electron diffraction screen, automatically tracking and measuring the specular spot width, and using numerical techniques to filter the resulting signal. The digitization and image and signal processing take approximately 0.4 s to accomplish, so this technique offers the molecular‐beam epitaxy grower the ability to actively adjust growth times in order to deposit a desired layer thickness. The measurement has a demonstrated precision of approximately 2%, which is sufficient to allow active control of epilayer thickness by counting monolayers as they are deposited. When postgrowth techniques, such as frequency domain analysis, are also used, the reflection high‐energy electron diffraction measurement of layer thickness on rotating substrates improves to a precision of better than 1%. Since all of the components in the system described are commercially available, duplication is straightforward.

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Additional Information:© 1995 American Vacuum Society. Received 14 March 1994; accepted 28 July 1995. The authors wish to thank H. J. Levy for his helpful input on numerical signal processing techniques. This work was supported by the office of Naval Research under Contract No. N00014-93-1-0710.
Funding AgencyGrant Number
Office of Naval Research (ONR)N00014-93-1-0710
Subject Keywords:Frequency domain analysis, growth rate, signal processing, digital systems, image processing, molecular beam epitaxy, real time systems, substrates
Issue or Number:5
Classification Code:PACS: 07.05.-t; 81.15.Hi
Record Number:CaltechAUTHORS:20120216-093141833
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Official Citation: Real‐time extraction of growth rates from rotating substrates during molecular‐beam epitaxy D. A. Collins, G. O. Papa, and T. C. McGill J. Vac. Sci. Technol. B 13, 1953 (1995);
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29330
Deposited By: Ruth Sustaita
Deposited On:16 Feb 2012 17:54
Last Modified:09 Nov 2021 17:06

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