Rodolfo Cuerno
Universidad Carlos III de Madrid, Matematicas, Faculty Member
- 1996-current: Universidad Carlos III de Madrid, Leganés, Spain
1994-1995: Boston University, Boston, USA
1990-1993: Insto. Matemáticas y Física Fundamental (CSIC), Madrid, Spainedit
Low-pressure chemical vapor deposition LPCVD is one of the most frequently used techniques for thin-film production in several industrial applications. 1 Silicon dioxide films have been extensively used in very large scale integrated... more
Low-pressure chemical vapor deposition LPCVD is one of the most frequently used techniques for thin-film production in several industrial applications. 1 Silicon dioxide films have been extensively used in very large scale integrated devices. Knowledge and eventual control of the morphology of silica films produced by CVD become very important as device dimensions are being continuously reduced. In particular, this control becomes critical when conformal growth ie, good step coverage is required.
A new model is introduced for two-dimensional crystalline interfaces with negligible surface tension. The model is given by a discrete version of the linear molecular beam epitaxy (MBE) equation plus an additional term periodic in the... more
A new model is introduced for two-dimensional crystalline interfaces with negligible surface tension. The model is given by a discrete version of the linear molecular beam epitaxy (MBE) equation plus an additional term periodic in the interface height variable. Langevin dynamics simulations and analytical arguments show that the model exhibits a roughening transition to the high temperature phase of the sine-Gordon model, whose initial stages are nevertheless described by the scaling of the linear MBE equation.
During the last decade, there have been great theoretical and experimental efforts to understand surface growth. This is due to possible applications, eg, to the production of thin films and, from the basic point of view, to the... more
During the last decade, there have been great theoretical and experimental efforts to understand surface growth. This is due to possible applications, eg, to the production of thin films and, from the basic point of view, to the interesting examples growing surfaces provide of nonequilibrium statistical systems 1, in some cases with strong relation to relevant equilibrium systems 2.
We study the critical behavior of the Laplacian roughening model, which describes the growth of tensionless surfaces. This type of growth phenomena is very important, for instance, in biological membranes and in molecular beam epitaxy. We... more
We study the critical behavior of the Laplacian roughening model, which describes the growth of tensionless surfaces. This type of growth phenomena is very important, for instance, in biological membranes and in molecular beam epitaxy. We summarize previous analytical and numerical results and point out their contradictions and differences, thus making clear the context of our work.
A lack of universality with respect to ion species has been recently established in nanostructuring of semiconductor surfaces by low-energy ion-beam bombardment. This variability affects basic properties of the pattern formation process,... more
A lack of universality with respect to ion species has been recently established in nanostructuring of
semiconductor surfaces by low-energy ion-beam bombardment. This variability affects basic properties of the
pattern formation process, like the critical incidence angle for pattern formation, and has remained unaccounted
for. Here, we show that nonuniform generation of stress across the damaged amorphous layer induced by
the irradiation is a key factor behind the range of experimental observations, as the form of the stress field
is controlled by the ion/target combination. This effect acts in synergy with the nontrivial evolution of the
amorphous-crystalline interface. We reach these conclusions by contrasting a multiscale theoretical approach,
which combines molecular dynamics and a continuum viscous flow model, with experiments using Xe + and Ar +
ions on a Si(100) target. Our general approach can apply to a variety of semiconductor systems and conditions.
semiconductor surfaces by low-energy ion-beam bombardment. This variability affects basic properties of the
pattern formation process, like the critical incidence angle for pattern formation, and has remained unaccounted
for. Here, we show that nonuniform generation of stress across the damaged amorphous layer induced by
the irradiation is a key factor behind the range of experimental observations, as the form of the stress field
is controlled by the ion/target combination. This effect acts in synergy with the nontrivial evolution of the
amorphous-crystalline interface. We reach these conclusions by contrasting a multiscale theoretical approach,
which combines molecular dynamics and a continuum viscous flow model, with experiments using Xe + and Ar +
ions on a Si(100) target. Our general approach can apply to a variety of semiconductor systems and conditions.
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We study kinetically rough surfaces which display anomalous scaling in local properties such as the rough- ness or the height-difference correlation function. By studying the power spectrum of the surface and its relation to the... more
We study kinetically rough surfaces which display anomalous scaling in local properties such as the rough- ness or the height-difference correlation function. By studying the power spectrum of the surface and its relation to the height-difference correlation, we distinguish two independent causes for anomalous scaling. One is superroughening ~global roughness exponent larger than or equal to 1!, even if the
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A microscopic, driven lattice gas model is proposed for the dynamics and spatiotemporal fluctuations of the precursor film observed in spreading experiments. Matter is transported both by holes and particles, and the distribution of each... more
A microscopic, driven lattice gas model is proposed for the dynamics and spatiotemporal fluctuations of the precursor film observed in spreading experiments. Matter is transported both by holes and particles, and the distribution of each can be described by driven diffusion with a moving boundary. This picture leads to a stochastic partial differential equation for the shape of the boundary.
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A Comment on the Letter by T. C. Kim et al., Phys. Rev. Lett. 92, 246104 (2004). The authors of the Letter offer a Reply. ... (Some reference links may require a separate subscription.) ... T. C. Kim, et al., Phys. Rev. Lett. 92, 246104... more
A Comment on the Letter by T. C. Kim et al., Phys. Rev. Lett. 92, 246104 (2004). The authors of the Letter offer a Reply. ... (Some reference links may require a separate subscription.) ... T. C. Kim, et al., Phys. Rev. Lett. 92, 246104 (2004). ... R. M. Bradley and J. M. E. Harper, ...
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We consider the Kardar-Parisi-Zhang equation for a circular interface in two dimensions, unconstrained by the standard small-slope and no-overhang approximations. Numerical simulations using an adaptive scheme allow us to elucidate the... more
We consider the Kardar-Parisi-Zhang equation for a circular interface in two dimensions, unconstrained by the standard small-slope and no-overhang approximations. Numerical simulations using an adaptive scheme allow us to elucidate the complete time evolution as a crossover between a short-time regime with the interface fluctuations of a self-avoiding ring or two-dimensional vesicle, and a long-time regime governed by the Tracy-Widom distribution expected for this geometry. For small-noise amplitudes, scaling behavior is only of the latter type. Large noise is also seen to renormalize the bare physical parameters of the ring, akin to analogous parameter renormalization for equilibrium three-dimensional membranes. Our results bear particular importance on the relation between relevant universality classes of scale-invariant systems in two dimensions.
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Interrupted coarsening (IC) has recently been identified as an important feature for the dynamics of the typical length-scale in pattern-forming systems on surfaces. In practice, it can be beneficial to improve pattern ordering since it... more
Interrupted coarsening (IC) has recently been identified as an important feature for the dynamics of the typical length-scale in pattern-forming systems on surfaces. In practice, it can be beneficial to improve pattern ordering since it combines a certain degree of defect suppression with a limited increase in the typical pattern wavelength. However, little is known about its robustness with respect to changes in the preparation of the initial system for cases with potential applications. Working in the context of nano-scale pattern formation by ion-beam sputtering (IBS), we prove that IC properties do not depend on sample preparation. Specifically, interface dynamics under IBS is quantitatively compared on virgin amorphous and crystalline silicon surfaces, using 1 keV Ar(+) ions at normal incidence where nanodot pattern formation is triggered by concurrent co-deposition of Fe atoms during processing. Atomic force microscopy shows that dot patterns with similar spatial order and dynamics are obtained in both cases, underscoring the key dynamical role of the amorphous surface layer produced by irradiation. Both systems have been quantitatively described by an effective interface equation. We employ a new procedure based on the linear growth of the initial surface correlations to accurately estimate the equation coefficients. Such a method improves the predictive power of the interface equation with respect to previous studies and leads to a better description of the experimental pattern and its dynamical features.