Scalable Submicron Channel Fabrication by Suspended Nanofiber Lithography for Short-Channel Field-Effect Transistors

Understanding the effect of short channels on the performance of field-effect transistors (FETs) from emerging low-dimensional semiconductors is crucial to estimate their suitability in high-density integrated circuits. To this end, intricate and costly equipment capable of nanoscale photolithography or e-beam lithography is usually required to fabricate FETs with shrinking channel lengths. Here, the authors propose an economical suspended nanofiber lithography technique with short-channel processing capability, and compatibility with modern semiconductor foundries. By combining the merits of the near-field electrohydrodynamic printing of nanofibers and microscale photolithographic process, the authors successfully fabricate short channels with lengths as small as 48 nm via masks of suspended nanofibers, whose diameters are easily tuned by adjusting the printing conditions. This technique is further applied for exploring the performance of short-channel FETs using semiconductors such as single-walled carbon nanotubes or electrochemically-exfoliated MoS2. Their performance is comparable to those made from more demanding lithography methods. This economical nanofabrication technique is promising to be applied on a variety of semiconductors for highly integrated fabrication of submicron short-channel device arrays.