Use of a focused ion beam for characterizing SIS circuits

Abstract

Fig. 1. An etched trilayer/Cr-Au test junction under a quadlevel resist structure before SiO deposition is shown. It can be seen that the SF6+CHF3-based Nb etch is anisotropic. The Cr-Au button is clearly seen to be defined by the NFR resist and not the trilevel resist Nb (which defines the Nb junction size). Abstract)) ))We have found the use of a Ga+ based focused ion beam (FIB) system to be very useful in characterizing our superconducting-insulating-superconducting (SIS) fabrication process. This tool enables us to physically carve cross sections in any feature of interest on our wafer which we can then image with an SEM. This process is used to examine and monitor improvements in the coverage of metalization layers over different circuit topography and in the critical "sealing" capabilities of our SiO insulation layer around the perimeter of the Nb junction counter electrode. It has also been used to better establish a submerged trilayer deposition process where the base electrode is imbedded in the quartz substrate. We have also improved our characterization of the tunnel barrier critical current density of our Nb/Al-oxide/Nb trilayer material by obtaining more accurate diameter measurements from FIB sectioned junctions. Index Items)) ))characterization, critical current density, cross section, and focused ion beam.

Attenuated Glial Reactivity on Topographically Functionalized Poly(3,4‐Ethylenedioxythiophene):P‐Toluene Sulfonate (PEDOT:PTS) Neuroelectrodes Fabricated by Microimprint Lithography

“…A range of techniques have been explored to create defined microstructures on electrode surfaces, including laser ablation, focused ion beam, sputter etching, reactive ion etching, deep reactive ion etching, hot embossing, and electron beam lithography . Complementary to these techniques, imprint lithography is an especially attractive approach due to its simplicity, nondestructive character, and feasibility of patterning large areas with features down to 10 nm using elevated temperature and/or pressure processes to transfer a pattern into typically thermoplastic materials .…”