Shadow Wall Epitaxy of Compound Semiconductors toward All in Situ Fabrication of Quantum Devices

The realization of advanced semiconductor nanostructures requires the development of epitaxial growth schemes to mitigate the detrimental effects of ex situ device processing. With this perspective, we introduce a selective growth concept for molecular beam epitaxy (MBE) in which parts of the sample area are shadowed using prefabricated walls. Systematic analysis of the crystalline and optical properties by X-ray diffraction techniques and photoluminescence reveal a comparably good quality of the structured ZnSe-based thin films, compared to reference samples. We transfer this concept toward epitaxy of more complex II–VI heterostructures to demonstrate the versatility of our epitaxial approach for the development of fully in situ processed quantum devices.