Crystal symmetry, step-edge diffusion and unstable growth

Abstract

We study the effect of crystal symmetry and step-edge diffusion on the surface current governing the evolution of a growing crystal surface. We find there are two possible contributions to anisotropic currents, which both lead to the destabilization of the flat surface: terrace current (j_t), which is parallel to the surface slope, and step current (j_s), which has components parallel (j_pa) and perpendicular (j_pe) to the slope. On a high-symmetry surface, terrace and step currents are generically singular at zero slope, and this does not allow to perform the standard linear stability analysis. As far as a one-dimensional profile is considered, (j_pe) is irrelevant and (j_pa) suggests that mound sides align along [110] and [1-10] axes. On a vicinal surface, (j_s) destabilizes against step bunching; its effect against step meandering depends on the step orientation, in agreement with the recent findings by O.Pierre-Louis et al. [Phys. Rev. Lett. 82, 3661 (1999)].

7 pages, 3 embedded EPS figures. Added a final section and a list of symbols. Accepted for publication in Surface Science

References in corpus (2)

• Coarsening Dynamics of Crystalline Thin Films
• The role of step edge diffusion in epitaxial crystal growth

Cited by in corpus (10)

• Four Lectures on the Physics of Crystal Growth
• Reverse epitaxy of Ge: ordered and facetted surface patterns
• Coexistence of bunching and meandering instability in simulated growth of 4H-SiC(0001) surface
• Competing mechanisms for step meandering in unstable growth
• Step bunching process induced by the flow of steps at the sublimated crystal surface
• Effect of kink-rounding barriers on step edge fluctuations
• Nonmonotonic roughness evolution in unstable growth
• Revisiting step instabilities on crystal surfaces. Part II: General theory
• Growth instability due to lattice-induced topological currents in limited mobility epitaxial growth models
• Universality classes for unstable crystal growth