AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Thursday Sessions
       Session NS-ThM

Paper NS-ThM1
Fabrication of Nanometer Size Photoresist Wire Patterns with a Silver Nanocrystal Shadowmask

Thursday, November 5, 1998, 8:20 am, Room 321/322/323

Session: Nanoscale Patterning and Modification
Presenter: S. Choi, University of California, Los Angeles
Authors: S. Choi, University of California, Los Angeles
K.L. Wang, University of California, Los Angeles
M. Leung, The Aerospace Corporation
G. Stupian, The Aerospace Corporation
N. Presser, The Aerospace Corporation
S. Chung, University of California, Los Angeles
G. Markovich, University of California, Los Angeles
S. Kim, University of California, Los Angeles
J.R. Heath, University of California, Los Angeles
Correspondent: Click to Email
We propose a new method of fabricating precisely defined nanometer size photoresist wire patterns by exposing electron beams onto silver(Ag) nanocrystal wires which have already been deposited on photoresist film. Ag nanocrystals linked with organic ligands were fabricated first using an organically functionalized Ag nanocrystal technique. Arrays of high aspect ratio wires formed spontaneously at the air/water interface when these Ag nanocrystals were dropped onto water. Ag nanocrystal wire structures were then transferred onto the polymethyl methacrylate(PMMA) coated substrates by the Langmuir-Blodgett lift-off process. To prepare a thick Ag nanocrystal shadowmask, a second monolayer of Ag nanocrystal wires was added to the previously deposited monolayer. The occupied areas by organic ligands between the nanocrystals in the wire decreased through a metallization process in air. Monte Carlo simulation was done to estimate the electron stopping effectiveness for the Ag nanocrystal shadowmask at low voltages. Low energy electron beam exposure resulted in numerous 50nm wide wire patterns on photoresist film. The wire patterns were defined in the photoresist material by spatially selective electron beam exposure on the Ag nanocrystal wire shadowmask. The wire patterns on photoresist film can be used for pattern transfer to many different substrates by subsequent selective etching for use in device fabrication. Our new method therefore enables rapid and low cost fabrication of quantum wire structures.