Nanoladder cantilevers made from diamond and silicon

TL;DR

This paper introduces a nanoladder cantilever design made from diamond and silicon that significantly reduces mechanical dissipation and force noise, enabling ultrasensitive measurements suitable for scalable fabrication.

Contribution

The authors present a novel nanoladder geometry for cantilevers that minimizes dissipation and can be batch-fabricated using standard lithography, unlike bottom-up nanostructures.

Findings

Achieved force noise of 158 zN in silicon at 100-150 mK

Demonstrated reduced mass and spring constant by two orders of magnitude

Fabricated nanoladder cantilevers using standard lithography

Abstract

We present a "nanoladder" geometry that minimizes the mechanical dissipation of ultrasensitive cantilevers. A nanoladder cantilever consists of a lithographically patterned scaffold of rails and rungs with feature size $\sim$ 100 nm. Compared to a rectangular beam of the same dimensions, the mass and spring constant of a nanoladder are each reduced by roughly two orders of magnitude. We demonstrate a low force noise of $158 (+62)(-42)\,$zN and $190 (+42)(-33)\,$zN in a one-Hz bandwidth for devices made from silicon and diamond, respectively, measured at temperatures between 100--150 mK. As opposed to bottom-up mechanical resonators like nanowires or nanotubes, nanoladder cantilevers can be batch-fabricated using standard lithography, which is a critical factor for applications in scanning force microscopy.