Cathode Design Optimization toward the Wide-Pressure-Range Miniature Discharge Ion Source for a Vacuum Micropump

Area of Science:

• Micro-Electro-Mechanical Systems (MEMS)
• Vacuum Technology
• Plasma Physics

Background:

• Generating and maintaining vacuum levels in MEMS devices is a significant challenge.
• Existing methods lack the capability for long-term, stable vacuum maintenance across wide pressure ranges.
• This limitation hinders the performance and application scope of various vacuum-based MEMS.

Purpose of the Study:

• To propose and demonstrate a new miniature ion source for wide-pressure-range vacuum generation.
• To address the difficulties in achieving and sustaining vacuum levels in MEMS devices.
• To provide a versatile solution applicable to vacuum micropumps and other vacuum systems.

Main Methods:

• A novel miniature ion source utilizing silicon electrodes and a glass substrate was designed.
• The device features a two-electrode structure with two-stage electrode spacing, operating under DC voltage.
• Gas discharge principles are employed, with automatic switching between electrode spacings to cover a wide pressure range.

Main Results:

• Two configurations were tested: without-magnet (atmospheric pressure to 1 mbar) and with-magnet (atmospheric pressure to 10⁻⁴ mbar).
• The ion source successfully operated across seven orders of magnitude of pressure.
• The device demonstrated a promising solution for generating and maintaining vacuum in MEMS.

Conclusions:

• The developed miniature ion source offers a viable solution for vacuum generation in MEMS devices.
• Its wide operating pressure range makes it suitable for vacuum micropumps, microgauges, and mass spectrometers.
• This technology advances the capabilities of vacuum MEMS and related applications.