Nanoscale silicon fluidic transfer for ultrahigh-density self-assembled integration

Fluidic self-assembly is an efficient fabrication technique that a large number of semiconductor chips are spontaneously integrated. However, the integrated chips in the experiments reported so far had dimensions of several tens of micrometers for the side lengths and thickness, hindered by the severe adhesiveness of smaller chips to their original substrates. Here we demonstrate fluidic transfer of submicron-scale chips. Simultaneous release and deposition of silicon thin-film chips are conducted in a blended solution of hydrofluoric acid and ethanol with ultrasonication, in relation to the surface tension. The mechanical bonding stability of the thin-film chips to the host chip is confirmed. Our scheme could lead to high-throughput, low-cost, and ultrahigh-density on-chip integration for electronic and photonic devices.