Flexible fabrication of aligned multi-nanowire circuits for on-chip prototyping

Circuits of multiple deterministically positioned semiconductor nanowires (NWs) is the basis of many devices for photonic, quantum, or conventional transistor applications. To explore and iterate on the design of larger circuits, the means to quickly place and electrically evaluate NWs at target locations must be developed. We propose and demonstrate a multi-NW circuit building concept on SiO 2 /Si substrates, which enables us to quickly position and orient NW components into pre-designed configurations. Micro-manipulator probes are used to guide the NWs into reactive ion etched trenches, with desired designs, before contact metallization. The positioning works over a wide combination of trench widths and depth. Positioning accuracies are contingent on EBL patterning, precise up to ± 10 nm. To demonstrate the concept, we create circuits of InP and InAs NWs with a wide variety of specific orientations. The concept was used to iterate a procedure for creating optimal contacts for InP NW photodiodes. Subsequently we could fabricate and electrically probe 54 fully operational nano-photodiodes placed on three different samples. The considerable statistics of the diode parameters could be obtained. Fabrication steps are directly compatible with conventional Si CMOS architecture and should function for a wide range of NW types. The accuracy and rate of placement combined with high fabrication yields enables proof-of-concept prototyping of complex circuits. • Fabricating method for prototyping circuits with multiple nanowires devices at specific positions and orientations on-chip. • Method demonstrated with several different types of nanowires. • Positioning with a precision of + − 10 nm is achievable for each nanowire device. • More than 50 functioning InP nanowire photodiode devices are fabricated on-chip and electrically evaluated. • Method enables the quick development of multi-nanowire circuits in a standard laboratory setting.