Experimental Verification of the Cluster Effect on Giant Step Bunching on 4H-SiC (0001) Surfaces

Abstract

In this study, we investigated the cluster effect on the occurrence of giant step bunching. We generated carbon clusters on 4H-SiC (0001) surfaces by thermal decomposition of SiC in an Ar atmosphere and controlled the surface concentrations of the clusters by adding H2 gas. We found the boundaries between surfaces with and without giant steps to show Arrhenius-type behavior. This behavior agreed with our predictions deduced from a chemical reaction model that takes the cluster effect into account, suggesting that giant step bunching is attributable to the formation of clusters on SiC.