Morphological evolution of pit-patterned Si(001) substrates driven by surface-energy reduction
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
Lateral ordering of heteroepitaxial islands can be conveniently achieved by suitable pit-patterning of the substrate prior to deposition. Controlling shape, orientation, and size of the pits is not trivial as, being metastable, they can significantly evolve during deposition/annealing. In this paper, we exploit a continuum model to explore the typical metastable pit morphologies that can be expected on Si(001), depending on the initial depth/shape. Evolution is predicted using a surface-diffusion model, formulated in a phase-field framework, and tackling surface-energy anisotropy. Results are shown to nicely reproduce typical metastable shapes reported in the literature. Moreover, long time scale evolutions of pit profiles with different depths are found to follow a similar kinetic pathway. The model is also exploited to treat the case of heteroepitaxial growth involving two materials characterized by different facets in their equilibrium Wulff's shape. This can lead to significant changes in morphologies, such as a rotation of the pit during deposition as evidenced in Ge/Si experiments.
Details
Original language | English |
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Article number | 554 |
Number of pages | 8 |
Journal | Nanoscale Research Letters |
Volume | 12 |
Publication status | Published - 29 Sept 2017 |
Peer-reviewed | Yes |
External IDs
Scopus | 85030640070 |
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ORCID | /0000-0002-4217-0951/work/142237426 |
Keywords
Keywords
- Epitaxy, Silicon, Surface diffusion, Surface energy, Phase field, Epitaxy, Silicon, Surface diffusion, Surface energy, Phase-Field modeling, Self-Organization, Ge Islands, Nanostructures, Heteroepitaxy, Thin films