Evaluation of resistless Ga⁺ beam lithography for UV NIL stamp fabrication

This paper presents an alternative rapid prototyping approach for the fabrication of stamps for UV nanoimprint lithography. In this process, areas implanted with gallium serve as an etch mask for the dry etching of quartz. The implantation is performed using a focused ion beam system. To avoid charging of the quartz substrate the use of thin layers of chromium or carbon on the quartz substrate has been evaluated. The resulting quartz structures exhibit very smooth surfaces after dry etching, if the implantation dose is high enough to form a stable etch mask. Furthermore, anisotropic etching could be realized by optimization of a quartz etching process involving C₄F₈ and O₂ after the use of resistless Ga(+) beam lithography. Finally, imprints into a UV curing resist are performed successfully with the manufactured stamps, proving that the presence of Ga rich areas on the stamp is not detrimental to the curing of the resist or the functionality of the anti-sticking layer.