Selective Area Growth of High-Quality In-Plane InAs Nanowires and Nanowire Networks by Molecular-Beam Epitaxy on Ge Substrates

• • The dual-indium-source two-step growth method achieves in-plane InAs nanowires with lengths exceeding 60 μm, a six-fold improvement over the single-source method (<10 μm), enabling scalable device fabrication. • • Optimization of As beam equivalent pressure suppresses overgrowth at network junctions, yielding uniform nanowire networks critical for quantum transport experiments. • • High-resolution transmission electron microscopy confirms pure zinc-blende crystal structure and sharp Ge/InAs interface, essential for coherent electron transport. • • The method is compatible with CMOS-compatible Ge substrates, offering a pathway to integrate III-V nanowires with silicon technology.