Flow-assisted Dielectrophoresis: A Low Cost Method for the Fabrication of High Performance Solution-processable Nanowire Devices

In this paper, flow assisted dielectrophoresis is demonstrated for the self-assembly of nanowire devices. The fabrication of a silicon nanowire field effect transistor is shown as an example.

The overall goal of this procedure is to demonstrate electric field assistance assembly and selection of high quality semi-conducting nanowires including fabrication of metal electrodes and use of these electrodes in flow-assisted dielectrophoresis to create solution-processable nanowire field effect transistors.This method can help us solve one of the main challenges in the field of solution-processable electronics such as placement of semi-conducting nanomaterials, control of the pilation done and field train of superior quality nanowires.The main function of this technique is that it's a fast reproducible method that can be scaled off controllable fabrication of nano material based devices.Although this method can provide insight into the alignment and selection of nanowires, it can also be applied in the alignment of nanotubes, nano flakes and blade-like nanomaterials.Most steps in this protocol take place in a clean room environment.Start with heavily doped four-inch N type silicon/silicon dioxide wafer.Use a diamond scribe to cut the wafer to produce suitably sized samples.Take care not to touch the top surface.Split the wafer along the cuts to yield several samples.The samples for this experiment are 2.5 x 2.5 centimeters.When done, take the samples to an ultrasonic bath.Place the samples on a substrate holder and immerse them in a beaker of deionized water.Sonicate the samples in the beaker for five minutes at full power.Then transfer the samples to a beaker with acetone before sonicating them for five minutes at full power again.Finally, transfer the samples to a beaker with isopropanol and sonicate for an additional five minutes at full power.Remove the samples from the ultrasonic bath and dry them with a nitrogen gun.Next, transfer the samples to a plasma asher to remove any remaining organic residues.For photolithography, move the samples to a yellow room.Work in a fume cupboard with a hotplate at 150