TRACING THE MOVEMENTS OF SINGLE ATOMS AND MOLECULES ON SOLID-SURFACES

Atoms and molecules on solid surfaces start to move at relatively low temperature. The dynamic behavior of atoms and molecules is responsibl e for crystal shape changes, crystal growth and thin film epitaxy, sur face enhanced chemical reactions and many other surface;phenomena wher e transport of atoms and molecules is involved. Identification of elem entary atomic processes in the dynamic behavior, and finding their mec hanisms and energetics are the key to understand these surface phenome na at the fundamental level. Using atomic resolution microscopy, it is now possible to trace the motion of single atoms and molecules on sol id surfaces from which elementary atomic processes can be identified a nd studied. Here, we discuss a few of our recent results at metal and semiconductor surfaces where novel mechanisms of atomic and molecular movements have been found. We also discuss how our result can be used to explain different growth modes existing in epitaxy.