Lateral Glow Discharge Ion Source for the Integrated MEMS Quadrupole Mass Spectrometer

This article presents a glow discharge ion source specifically designed for integration into a fully MEMS-based quadrupole mass spectrometer. The main challenge was to develop an ion source in the form of a multi-layer structure capable of extracting an ion beam in lateral direction and directing it toward the analyzer. Throughout the study, several test structures with varying degrees of complexity were proposed and tested. As anticipated, a trade-off was observed, where successive simplifications of the structure’s geometry led to a reduced operating pressure range and lower emitted ion currents. The structure that proved to be the most technologically compatible with the proposed mass spectrometer demonstrated sufficient efficiency, operating in medium vacuum range (from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 10^{-3}$ </tex-math></inline-formula> hPa) to high vacuum (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 10^{-5}$ </tex-math></inline-formula> hPa), with extracted ion currents reaching tens of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>A.[2024-0140]