TY - JOUR AB - Laterally aligned multilayer GeSiSi islands grown on a patterned Si (001) substrate are disclosed by selective etching of Si in a KOH solution. This procedure allows us to visualize the vertical alignment of the islands in a three-dimensional perspective. Our technique reveals that partly coalesced double islands in the initial layer do not merge together, but instead gradually reproduce into well-separated double islands in upper layers. We attribute this effect to very thin spacer layers, which efficiently transfer the strain modulation of each island through the spacer layer to the surface. The etching rate of Si is reduced in tensile strained regions, which helps to preserve sufficient Si between the stacked islands to form a periodic array of freestanding and vertically modulated heterostructure pillars. AU - Zhong, Zheyang AU - Georgios Katsaros AU - Stoffel, Mathieu AU - Costantini, Giovanni AU - Kern, Klaus AU - Schmidt, Oliver G AU - Jin-Phillipp, Neng Y AU - Bauer, Günther ID - 1743 IS - 26 JF - Applied Physics Letters TI - Periodic pillar structures by Si etching of multilayer GeSi/Si islands VL - 87 ER -