Unlocking new contrast in a scanning helium microscope.

M Barr,D J Ward,A Fahy,A P Jardine,W Allison,J Martens,P C Dastoor,J Ellis

doi:10.1038/ncomms10189

M Barr, D J Ward + Show 6 more

Open Access

https://doi.org/10.1038/ncomms10189

Copy DOI

Abstract

Delicate structures (such as biological samples, organic films for polymer electronics and adsorbate layers) suffer degradation under the energetic probes of traditional microscopies. Furthermore, the charged nature of these probes presents difficulties when imaging with electric or magnetic fields, or for insulating materials where the addition of a conductive coating is not desirable. Scanning helium microscopy is able to image such structures completely non-destructively by taking advantage of a neutral helium beam as a chemically, electrically and magnetically inert probe of the sample surface. Here we present scanning helium micrographs demonstrating image contrast arising from a range of mechanisms including, for the first time, chemical contrast observed from a series of metal–semiconductor interfaces. The ability of scanning helium microscopy to distinguish between materials without the risk of damage makes it ideal for investigating a wide range of systems.

Highlights

Delicate structures suffer degradation under the energetic probes of traditional microscopies
Scanning helium microscopy (SHeM) is a spatially resolved variant of helium atom scattering (HAS) that operates analogously to a scanning electron microscope, with the electron beam replaced with a beam of neutral helium atoms[6,7]
The field of atom optics is well established[4,14,15,16,17] and SHeM is already exceeding the resolution limits of traditional optical microscopy[18], the specific scattering mechanisms by which SHeM image contrast arises is a new area of research

Summary

Introduction

Delicate structures (such as biological samples, organic films for polymer electronics and adsorbate layers) suffer degradation under the energetic probes of traditional microscopies. Scanning helium microscopy is able to image such structures completely non-destructively by taking advantage of a neutral helium beam as a chemically, electrically and magnetically inert probe of the sample surface. With modern fabrication taking advantage of an ever-broader library of new materials, microscopy techniques need to be applicable to a wide range of organic and inorganic samples[1,2]. The field of atom optics is well established[4,14,15,16,17] and SHeM is already exceeding the resolution limits of traditional optical microscopy[18], the specific scattering mechanisms by which SHeM image contrast arises is a new area of research. We show that current theory is not yet capable of fully explaining the observed contrast

Methods

Results

Conclusion