[Un modèle pour le démouillage solide–solide dʼun film mince complètement facetté]
Du fait de leurs rapports dʼaspect extrêmement élevés, la plupart des films fins sont instables et, lorsquʼils sont chauffés, ils démouillent ou sʼagglomèrent pour former des îlots. Ce processus peut se produire à lʼétat solide grâce à la diffusion de surface induite par la capillarité. Un trait caractéristique du processus de démouillage est la rétractation des bords du film, quʼils soient naturels ou structurés, ou autour des trous qui se forment dans le film. Des modèles de rétractation de bords ont été précédemment développés pour des matériaux isotropes et anisotropes avec des surfaces différentiables, mais les effets du facettage dans les matériaux hautement anisotropes sont largement inexplorés. Nous présentons ici un modèle à deux dimensions de la rétractation des bords pour des films minces hautement anisotropes, complètement facettés. Ce modèle montre généralement un bon accord avec les résultats expérimentaux pour la rétractation de films de nickel monocristallins sur MgO. À la fois dans les expériences et le modèle, des fronts se forment lorsque les bords se rétractent. Les effets de lʼajustement de divers paramètres physiques sur le taux de rétractation des bords et la géométrie des bourrelets en évolution ont été explorés en utilisant le modèle. Lʼépaisseur du film, lʼautodiffusivité de surface sur la facette supérieure du front, lʼangle de contact équivalent du film sur le substrat, ainsi que la valeur absolue des énergies de surface se sont révélés être les facteurs qui influencent le plus le taux de rétractation des bords. Dans les modèles isotropes et certains systèmes expérimentaux, des vallées se forment à lʼavant des fronts de rétractation et sʼapprofondissent pour entrer en contact avec le substrat et mener à la rupture du film. Notre modèle suggère que cette forme de rupture ne se produira pas lorsque le front est complètement facetté et que sa surface supérieure est une facette dʼéquilibre. Pourtant, cette rupture du film peut survenir via lʼamincissement de films ainsi que pour des films dont les surfaces supérieures ne forment pas de facettes dʼéquilibre.
Owing to their extremely aspect ratios, most thin films are unstable and when they are heated, they will dewet or agglomerate to form islands. This process can occur in the solid state through capillary-driven surface self-diffusion. A key feature of the dewetting process is the retraction of the edges of the film, either natural edges, patterned edges, or edges where holes have formed. Models of edge retraction have been previously developed for isotropic materials and anisotropic materials with differentiable surfaces, but the effects of faceting in highly anisotropic materials have been largely unexplored. Here, we present a two-dimensional model of edge retraction for highly anisotropic, fully-faceted thin films. This model shows generally good agreement with experimental results for edge retraction of single-crystal Ni films on MgO. In both experiments and the model, rims form as the edges retract. The effects of adjusting various physical parameters on the edge retraction rate and the evolving rim geometry were explored using the model. The film thickness, surface self-diffusivity on the top facet of the rim, the equivalent contact angle of the film on the substrate, and the absolute value of the surface energies were found to be the factors that have the greatest influence on the edge retraction rate. In isotropic models and some experimental systems, valleys form ahead of the retracting rims and deepen to contact the substrate and cause pinch-off. Our model suggests that this form of pinch-off will not occur when the rim is fully faceted and the top surface is an equilibrium facet. However, pinch-off can occur through film thinning and for films with top surfaces that do not form flat equilibrium facets.
Mots-clés : Films minces, Démouillage, Capillarité, Milieux crystallins, Anisotropie, État solide
Rachel V. Zucker 1 ; Gye Hyun Kim 1 ; W. Craig Carter 1 ; Carl V. Thompson 1
@article{CRPHYS_2013__14_7_564_0,
author = {Rachel V. Zucker and Gye Hyun Kim and W. Craig Carter and Carl V. Thompson},
title = {A model for solid-state dewetting of a fully-faceted thin film},
journal = {Comptes Rendus. Physique},
pages = {564--577},
publisher = {Elsevier},
volume = {14},
number = {7},
year = {2013},
doi = {10.1016/j.crhy.2013.06.005},
language = {en},
}
TY - JOUR AU - Rachel V. Zucker AU - Gye Hyun Kim AU - W. Craig Carter AU - Carl V. Thompson TI - A model for solid-state dewetting of a fully-faceted thin film JO - Comptes Rendus. Physique PY - 2013 SP - 564 EP - 577 VL - 14 IS - 7 PB - Elsevier DO - 10.1016/j.crhy.2013.06.005 LA - en ID - CRPHYS_2013__14_7_564_0 ER -
Rachel V. Zucker; Gye Hyun Kim; W. Craig Carter; Carl V. Thompson. A model for solid-state dewetting of a fully-faceted thin film. Comptes Rendus. Physique, Trends and perspectives in solid-state wetting / Mouillage solide-solide : tendances et perspectives, Volume 14 (2013) no. 7, pp. 564-577. doi : 10.1016/j.crhy.2013.06.005. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2013.06.005/
[1] The mobility of the surface atoms of copper and silver evaporated deposits, March 1966 (Royal Aircraft Establishment Technical Report 66095)
[2] Capillary instabilities in thin films, J. Electron. Mater., Volume 19 (1990), p. 1153
[3] Capillary instabilities in thin, continuous films, Thin Solid Films, Volume 208 (1992), p. 23
[4] Surface-energy-driven dewetting theory of silicon-on-insulator agglomeration, J. Appl. Phys., Volume 100 (2006), p. 083507
[5] Mechanisms of complex morphological evolution during solid-state dewetting of single-crystal nickel thin films, Appl. Phys. Lett., Volume 97 (2010), p. 071904
[6] Agglomeration control during the selective epitaxial growth of Si raised sources and drains on ultra-thin silicon-on-insulator substrates, J. Cryst. Growth, Volume 280 (2005), p. 530
[7] Periodic organic nanodot patterns for optical memory, Nano Lett., Volume 7 (2007), p. 3845
[8] Growth process conditions of vertically aligned carbon nanotubes using plasma enhanced chemical vapor deposition, J. Appl. Phys., Volume 90 (2001), p. 5308
[9] Silicon nanowires: A review on aspects of their growth and their electrical properties, Adv. Mater., Volume 21 (2009), p. 2681
[10] Thermal and chemical vapor deposition of Si nanowires: Shape control, dispersion and electrical properties, J. Appl. Phys., Volume 102 (2007), p. 034302
[11] Activating technology of SnO2 layers by metal particles from ultra thin metal films, Sens. Actuators B, Chem. (1993), p. 328
[12] Formation and ordering of self-assembled Si islands by ultrahigh vacuum annealing of ultrathin bonded silicon-on-insulator structure, Appl. Surf. Sci., Volume 159 (2000), p. 121
[13] Mechanisms of thermally induced dewetting of ultrathin silicon-on-insulator, Appl. Phys. Lett., Volume 88 (2006), p. 141924
[14] Thermal agglomeration of ultrathin silicon-on-insulator layers: Crystalline orientation dependence, Jpn. J. Appl. Phys., Volume 47 (2008), p. 1461
[15] Templated solid-state dewetting to controllably produce complex patterns, Adv. Mater., Volume 23 (2011), p. 1567
[16] Shape evolution by surface attachment limited kinetics on completely faceted surfaces, Acta Metall. Mater., Volume 43 (1995), p. 4309
[17] Capillary instabilities in thin films. I. Energetics, J. Appl. Phys., Volume 60 (1986), p. 247
[18] Theory of thermal grooving, J. Appl. Phys., Volume 28 (1957), p. 333
[19] Capillary instabilities in thin films. II. Kinetics, J. Appl. Phys., Volume 60 (1986), p. 255
[20] Periodic mass shedding of a retracting solid film step, Acta Mater., Volume 48 (2000), p. 1719
[21] Surface diffusion dewetting of thin solid films: Numerical method and application to Si/SiO2, Phys. Rev. B, Volume 73 (2006), p. 115427
[22] Regular pattern formation through the retraction and pinch-off of edges during solid-state dewetting of patterned single crystal films, Phys. Rev. B, Volume 82 (2010), p. 193408
[23] Anisotropic edge retraction and hole growth during solid-state dewetting of single crystal nickel thin films, Acta Mater., Volume 59 (2011), p. 582
[24] Dynamics of solid thin-film dewetting in the silicon-on-insulator system, New J. Phys., Volume 13 (2011), p. 043017
[25] Kinetics of a retracting solid film edge: The case of high surface anisotropy, Scr. Mater., Volume 64 (2011), p. 962
[26] Quantitative analysis of anisotropic edge retraction by solid-state dewetting of thin single crystal films, J. Appl. Phys. (2013) (in press)
[27] Dynamics, anisotropy, and stability of silicon-on-insulator dewetting fronts, Phys. Rev. B, Volume 85 (2012), p. 195414
[28] Fingering instability of retracting solid film edge, J. Appl. Phys., Volume 97 (2005), p. 043515
[29] The Physics of Powder Metallurgy (C. Herring; W.E. Kingston, eds.), McGraw–Hill, New York, 1951, p. 143
[30] Evolution of two-dimensional crystal morphologies by surface diffusion with anisotropic surface free energies, Comput. Mater. Sci., Volume 27 (2003), p. 461
[31] Mean curvature and weighted mean curvature, Acta Metall. Mater., Volume 40 (1992), p. 1475
[32] Zur Frage der Geschwindigkeit des Wachstums und der Auflösung der Kristallflächen, Z. Kristallogr., Volume 34 (1901), p. 449
[33] Equilibrium shape of a small particle in contact with a foreign substrate, Acta Metall., Volume 15 (1967), p. 303
[34] Surface self-diffusion and surface energy of nickel, J. Appl. Phys., Volume 38 (1967), p. 698
[35] Predicting trends in rate parameters for self-diffusion of FCC metal surfaces, Surf. Sci., Volume 515 (2002), p. 21
[36] The surface energy of metals, Surf. Sci., Volume 411 (1998), p. 186
[37] Nanostructure formation in the initial roughening of a thin silicon sheet, Phys. Rev. B, Volume 81 (2010) 041302(R)
[38] Nanocrystal formation and faceting instability in A1(110) homoepitaxy: True upward adatom diffusion at step edges and island corner, Phys. Rev. Lett., Volume 91 (2003), p. 016102
Cité par Sources :
Commentaires - Politique
Vous devez vous connecter pour continuer.
S'authentifier