In SituReal-Time Observation of Thin Film Deposition: Roughening, Zeno Effect, Grain Boundary Crossing Barrier, and Steering

We report on the first atomic-scale real-time in situ investigation of the growth of a polycrystalline gold film during its deposition performed with a scanning tunneling microscope. Continuously scanning while depositing the film enables the direct observation of atomic processes. The grain boundaries play a crucial role in the evolving film structure, as they initiate mound formation, thereby significantly increasing the film roughness. A possible additional roughness increase comes from atom steering, which also can delay the film closure in the early stages during film growth.