Visualization of the inverse layer-plus-island growth in Fe islands on W(110) substrate

•We have grown Fe islands on W(110) substrate using the shadow mask technique.•We have visualized the initial growth stage of the Stranski–Krastanov mode.•We have controlled the growth mode from island-plus-layer growth to layer-plus-island growth.

Many experiments have been conducted so far to control the growth mode in heterostructures, but success has only been restricted to strain-controlled growth systems. In this study, using the shadow mask deposition technique, we have changed the growth mode in the Fe/W heterostructures from the layer-plus-island growth mode to island-plus-layer growth mode. From this, we have ignited the competing growth between forming the islands and wetting the first layer, and have directly visualized the island-plus-layer growth by controlling the annealing temperature of the system. This unconventional growth mode may play an important role in studying the hidden boundaries of hetero-interfaces.