Effect of Cu impurities on wet etching of Si(110): formation of trapezoidal hillocks
نویسندگان
چکیده
We simulate the formation of experimentally observed trapezoidal hillocks on etched Si(110) surfaces, describing their generic geometrical shape and analyzing the relative stability and/or reactivity of the key surface sites. In our model, the hillocks are stabilized by Cu impurities in the etchant adsorbing on the surface and acting as pinning agents. A model of random adsorptions will not result in hillock formation since a single impurity is easily removed from the surface. Instead a whole cluster of Cu atoms is needed as a mask to stabilize a hillock. Therefore we propose and analyze mechanisms that drive correlated adsorptions and lead to stable Cu clusters. 5 Author to whom any correspondence should be addressed. New Journal of Physics 10 (2008) 013033 1367-2630/08/013033+19$30.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
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