In-situ high-temperature scanning-tunnelling-microscopy studies of two-dimensional island-decay kinetics on atomically smooth TiN(001)

In-situ high-temperature scanning tunneling microscopy was used to follow t he coarsening (Ostwald ripening) and decay kinetics of single and multiple two-dimensional TiN islands on atomically flat TiN(001) terraces and in sin gle-atom deep vacancy pits at temperatures of 750-950 degreesC. The rate-li miting mechanism for island decay was found to be surface diffusion rather than adatom attachment/detachment at island edges. We have modeled island-d ecay kinetics based upon the Gibbs-Thomson and steady state diffusion equat ions to obtain a step-edge energy per unit length of 0.23 +/- 0.05 eV/Angst rom and an activation energy for adatom formation and diffusion of 3.4 +/- 0.3 eV.