Title: Process model-based analysis of highly crystalline and chemically pure molecular beam epitaxy of MgO (111) nano-thin films on 6H-SiC (0001) substrates

Authors: Ghulam Moeen Uddin; Katherine S. Ziemer; Abe Zeid; Sagar Kamarthi

Addresses: Mechanical Engineering Department, University of Engineering and Technology Lahore, G.T. Road, Lahore 54890, Pakistan ' Chemical Engineering Department, Northeastern University, Boston, MA 02115, USA ' Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115, USA ' Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115, USA

Abstract: A highly two-dimensional and chemically pure MgO (111) thin film grown epitaxially under ultra-high vacuum on a (√3 × √3) R30° reconstructed wideband gap 6H-SiC (0001) substrate surface can serve as a promising minimal mismatch interfacial layer between the substrate surface and a crystalline structure of functional oxide film. However, the reliability and repeatability of the growth process is challenging. In this paper the dynamic termination of the MgO (111) polar oxide during layer-by-layer growth is explained by OH group chemical bonding state of MgO structure. The analysis of causal relationships is conducted at three different thickness levels to account for the sensitivity of film chemistry to the mismatching strain related inherent twist of crystalline structure along the film thickness. The contribution of sources of the undesired bonding states is quantified by examining the process sensitivity trends to the most critical process variable (percentage starting oxygen) at different thickness levels.

Keywords: nanomanufacturing; process modelling; molecular beam epitaxy; MBE; magnesium oxide; MgO; nano thin films; functional oxide heterostructures; design of experiments; DOE; Monte Carlo experiments; response surface regression; neural networks; interface engineering; chemical bonding; film thickness; nanotechnology.

DOI: 10.1504/IJNM.2015.070521

International Journal of Nanomanufacturing, 2015 Vol.11 No.1/2, pp.25 - 45

Accepted: 19 Sep 2014
Published online: 09 Jul 2015 *

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