INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Basic mechanisms for hillock formation during etching
Autor/es:
D.A. MIRABELLA, M.P. SUÁREZ, Y C.M. ALDAO
Lugar:
Bahía Blanca
Reunión:
Congreso; III Encuentro de Física y Química de Superficies; 2007
Resumen:
Nonequilibrium processes at surfaces associated with epitaxial growth and etching have been and continue to be of great interest.  Both processes are of technological relevance because of their role in the fabrication of microelectronic devices.  Experimental studies show that some surfaces are smooth after etching while others are covered with pits and hillocks.  For Si(100), the atomic level changes that accompany etching solutions present distinct pyramidal hillocks.  Conversely, in vicinal Si(111) surfaces steps are attacked much faster than terraces.  Thus, if steps etch independently, step-flow predominates.  In this case, the surface morphology is dominated by step roughening since terraces are rarely attacked.  Therefore, modeling describing steps reduces to a one-dimensional problem.  In this work we explore the consequences of site-dependent detachment probabilities in the formation of etch hillocks for a simple one-dimensional Kossel substrate.  Monte Carlo simulations were carried out within a restricted-solid-on-solid model in which only first neighbor interactions are considered.  We specially focus on describing the dynamics that lead to hillock-and-valley patterns.  The mechanisms responsible for the steady state morphologies are related to apex creation and annihilation, together with valley and hillock etching, but pattern formation reflects two feedback loops that interrelate these mechanisms.