Fabrication of high-aspect-ratio nanotips integrated with single-crystal siliconcantilevers

Abstract

This work presents a novel fabrication technique for an atomic force microscope (AFM)nanotip. The high-aspect-ratio silicon nanotip on a single-crystal silicon cantilever wasmanufactured using inductive coupling plasma (ICP) anisotropic etching andXeF2 isotropic silicon etching processes. The cantilever shape was defined and the high-aspect-ratiosilicon nanotip structure was fabricated by ICP anisotropic deep silicon etching(∼50–80 µm deep). Nanotip sharpening and single-crystal Si cantilever undercutting were achieved simultaneously viatwo-step XeF2 isotropic silicon etching. The final structures were observed by a scanningelectron microscope (SEM) and the diameter of the nanotip was about∼30 nm. This process is simple, easy to use, CMOS post-process-compatible and suitable for thefuture IC integrated AFM nanotip applications.