Self‐Align Fabrication of Narrow‐Gapped Dual AFM Tip Using Si Trench Refilling with SOG and Magnetostrictive Film Stacked Dual Cantilever Formation

Abstract

SUMMARYThis paper reports on a novel self‐align fabrication process of narrow‐gapped dual AFM (atomic force microscope) tip. The dual AFM tip was fabricated on (100) orientated Si substrate by using narrow trench etching, trench refilling with SOG (spin‐on‐glass), CMP (chemical–mechanical polishing), and Si crystalline anisotropic etching. Through the process, a sharp dual AFM tip with a gap of 500 nm, which was defined only by the etched trench width, was successfully fabricated. Although another fabrication process using an acrylic‐nitrile‐styrene‐epoxy resin refilling was also attempted, a dual tip was not obtained due to the poor adhesion of the resin in the silicon etching process. In addition, a dual AFM cantilever (magnetostrictive film/Si 2.0 μm) was formed by MEMS fabrication. The fabricated FePd 0.4 μm/Si 2.0 μm and Ni 1.3 μm/Si 2.0 μm cantilever were individually deflected to 1.4 μm at 300 Gauss and 0.4 μm at 240 Gauss due to effects of magnetic flux and negative magnetostriction, respectively.