Mass-loaded cantilevers with suppressed higher-order modes for magnetic resonance force microscopy

Abstract

We describe the design, fabrication and testing of mass-loaded cantilevers for electron-spin magnetic resonance force microscopy. These single-crystal silicon cantilevers are designed to have large gaps in their thermal mode spectra so as to reduce thermal noise near the electron-spin Rabi frequency. Each cantilever typically consists of a 2 μm thick mass suspended at the end of a 0.1 μm thick hinge. The fabrication process starts with an SOI wafer followed by selective silicon epitaxy, cantilever patterning, and backside release. The focus of the process is on precise thickness control and material homogeneity. We will present characterization results for these cantilevers at room and low temperatures and discuss the impact of these devices on magnetic resonance force microscopy measurements.