Optimization of 3D patterning by Ga implantation and reactive ion etching (RIE) for nanoimprint lithography (NIL) stamp fabrication

Nanoimprint lithography (NIL) has the unique capability to replicate 3D patterns in one single step. However, to exploit this feature high quality, 3D patterned NIL stamps are required. While grayscale electron-beam lithography suffers from resolution limitations due to proximity effects, focused ion beam (FIB) milling and gas assisted etching is inherently slow. We introduce a new 3D patterning process based on FIB implantation and subsequent reactive ion etching (RIE) for NIL stamp fabrication. The presented process is more than 100 times faster than FIB milling. We demonstrate NIL stamps with complex 3D patterns and resolutions down to 50 nm fabricated with this process.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A new fabrication process for 3D NIL stamps is introduced. ► 3D pattern definition is achieved by locally confined Ga implantation with a FIB. ► EDX is introduced as fast, in situ method for the assessment of the implanted dose. ► Our optimized patterning process is up to 130 times faster than FIB milling. ► 3D patterned NIL stamps with 50 nm half pith resolution are demonstrated.