In-situ Plasma Studies using a Direct Current Microplasma in a Scanning Electron Microscope

TL;DR

This paper introduces a novel in-situ plasma study setup inside a scanning electron microscope, enabling real-time imaging of plasma-sample interactions with high spatial resolution, useful for materials science and nanotechnology applications.

Contribution

A stable DC microplasma setup integrated into a SEM, allowing real-time imaging of plasma effects on samples at micro-scale resolution.

Findings

Demonstrated localized sputtering and oxidation during plasma operation

Explored effects of gas mixtures, electrode polarity, and field strength

Provided $V$-$I$ curves under various experimental conditions

Abstract

Microplasmas can be used for a wide range of technological applications and to improve our understanding of fundamental physics. Scanning electron microscopy, on the other hand, provides insights into the sample morphology and chemistry of materials from the mm-down to the nm-scale. Combining both would provide direct insight into plasma-sample interactions in real-time and at high spatial resolution. Up till now, very few attempts in this direction have been made, and significant challenges remain. This work presents a stable direct current glow discharge microplasma setup built inside a scanning electron microscope. The experimental setup is capable of real-time in-situ imaging of the sample evolution during plasma operation and it demonstrates localized sputtering and sample oxidation. Further, the experimental parameters such as varying gas mixtures, electrode polarity, and field strength are explored and experimental $V$-$I$ curves under various conditions are provided. These results demonstrate the capabilities of this setup in potential investigations of plasma physics, plasma-surface interactions, and materials science and its practical applications. The presented setup shows the potential to have several technological applications, e.g., to locally modify the sample surface (e.g., local oxidation and ion implantation for nanotechnology applications) on the $\mu$m-scale.