Bi-Level Structures for Focused Ion Beam Using Maskless Ion Etching

Abstract

This paper proposes a bi-level structure for a maskless ion etching using focused ion beam. The bi-level structure can be realized by using a new phenomenon, wherein the Ga⁺ doped AZ1450J bottom layer is etched off by a high dose of more than 0.76 µC/cm. A Si top layer with 70 nm linewidth is fabricated. The linewidth can be controlled to nanometer dimensions by changing the dose. Moreover, fine structures with 100 nm are demonstrated using bi-level structures for the substrate etching and lift-off processes.