A new fiducial grid suitable for low-energy (1-5 keV) spatial-phase locked electron-beam lithography (SPLEBL) has been developed based on an aluminum layer with an organosilane grid pattern. The grids (400 nm period) were made of two to three layers of 3-amino-propyl-triethoxy-silane (APTES) that was microcontact printed onto Al coated polymethyl methacrylate (PMMA). Signal-to-noise ratios (SNRs) were measured at beam energies ranging from 1 to 5 keV at a dose of 20 μC/cm2 and compared to the SNRs of octadecanethiol (ODT) based fiducial grids on Au, Ag, and Cu. Although fiducial grids made of ODT on Au provided excellent SNR, Au is not suitable because of poor penetration and strong scattering of the primary electrons. ODT based grids on lower atomic number metal such as Ag or Cu yielded inadequate SNRs. In contrast, APTES-based grids on Al provide SNRs approaching ODT on Au with greatly reduced electron scattering. The authors successfully developed a grid removal process that allows patterns to be resolved in the underlying PMMA. These results represent a key step in the development of low-energy SPLEBL.
|Number of pages||5|
|Journal||Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures|
|State||Published - 2009|
Bibliographical noteFunding Information:
This material is based on work supported by the National Science Foundation under Grant No. CMMI-0609241. Electron-beam lithography and nanofabrication infrastructure was partially supported by NSF EPSCOR Award No. EPS-0447479. Experiments at the University of Kentucky were conducted within the Center for Nanoscale Science and Engineering (CeNSE). Brian Wajdyk and Chuck May provided valuable technical assistance.
ASJC Scopus subject areas
- Condensed Matter Physics
- Electrical and Electronic Engineering