Electroless metal discharge layers for electron beam lithography

TLDR: In this paper, the authors used a room temperature, aqueous-based, electroless deposition technique on silica and polymer planarizer surfaces for fabrication of continuous, conformal, ultrathin (i.e., 15-30 nm) Cu films, which are sufficiently homogeneous, electrically conductive, and optically transparent for use as resist discharge layers during resist discharge.

Abstract: We report a method for fabrication of continuous, conformal, ultrathin (i.e., 15–30 nm) Cu films using a room temperature, aqueous-based, electroless deposition technique on silica and polymer planarizer surfaces. The Cu films are sufficiently homogeneous, electrically conductive, and optically transparent for use as resist discharge layers during e-beam patterning of the substrate. The grounded Cu film, deployed here as a resist underlayer, eliminates the 0.1–0.4 μm subfield stitching errors normally observed in the absence of the Cu film during resist patterning on a glass or insulating substrate. The Cu is readily removed using a nitric acid wet etch following patterning.