2005 APS March Meeting
Monday–Friday, March 21–25, 2005;
Los Angeles, CA
Session D40: Focus Session: Morphology and Evolution at Surfaces: Epitaxy
2:30 PM–5:18 PM,
Monday, March 21, 2005
LACC
Room: 408A
Sponsoring
Units:
DMP DCMP
Chair: Jim Hannon, IBM Research
Abstract ID: BAPS.2005.MAR.D40.1
Abstract: D40.00001 : Effects of Steering and Shadowing in Epitaxial Growth
2:30 PM–3:06 PM
Preview Abstract
Abstract
Author:
Jacques Amar
(University of Toledo)
While shadowing has been known to play a role in some thin-film
deposition processes, until recently it has been assumed that in
epitaxial growth the effects of steering and shadowing are
negligible. Here we present analytical and molecular dynamics
results describing the effects of steering due to the short-range
and long-range van der Waals (vdW) attraction in metal (100),
(111) and (110) epitaxial growth. Our results lead to a general
picture of the process of deposition near step-edges$^{1,2}$
which is quite different from the standard downward funneling
picture. In particular, we find that short-range attraction plays
an important role not only {\it before} but also {\it after}
collision with the step. As a result, it can significantly
enhance the uphill current, selected mound angle, and surface
roughness in epitaxial growth. In the case of deposition on metal
(111) and (110) surfaces we also find a significant asymmetry
between the interaction at A and B steps which may be explained
by differences in the step geometry. General expressions for the
surface current and selected mound angle valid for arbitrary
crystal geometry are also presented. We have also calculated the
vdW constant describing the long-range interaction between a Cu
atom and a Cu(100) surface.$^3$ Our result is large enough to
explain recent observations$^4$ of a significant increase in
mound angle in Cu/Cu(100) growth for large angles of incidence
($\theta > 50^{\circ}$) and also indicates that for smaller angles of
incidence the dominant effects are due to the short-range rather
than to the long-range interaction. Finally, we discuss the
effects of shadowing in oblique incidence epitaxial growth and
its implications for the control of nanoscale patterning.\\
1. J. Yu and J.G. Amar, Phys. Rev. Lett. {\bf 89}, 286103 (2002).\\
2. J. Yu and J.G. Amar, Phys. Rev. B {\bf 69}, 045426 (2004).\\
3. J.G. Amar, Phys. Rev. B {\bf 67}, 165425 (2003).\\
4. S. van Dijken et al, Phys. Rev. B {\bf 61}, 14047 (2000).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.MAR.D40.1