Filling of high aspect ratio (HAR) nanometer-scale silicon trenches by electrochemical deposition of nickel

This report presents an electrochemical deposition process (ECD) of nickel in submicrometer to nanometer silicon trenches with an aspect ratio greater than 25 over a grating area of several square millimeters. Due to the use of silicon substrates with a very low electrical resistivity in the range of 0.005 to 0.01 O·cm, a prior deposition of an electrically conductive seed layer was not necessary. To fabricate the samples for electrodeposition, silicon gratings of 200 nm periods were patterned with nanoimprint lithography and etched to around 2 - 4 microns by deep reactive ion etching (DRIE).