Research Interest

My research focuses on both experimental and computational studies of low-pressure microwave plasmas, particularly their use in focused ion beam systems. I also investigate the quantum behavior of low-energy helium ions to develop advanced quantum technologies like sensors and detectors.

A. Microwave Plasma-Based Focused Ion Beams (FIBs) 

We utilize low-pressure microwave plasmas to generate high-current, stable ion beams, critical for advanced applications in nanofabrication and materials analysis. Our research focuses on achieving high-intensity nano-ion beams by optimizing system parameters and exploring innovative methods in charged particle optics. These advancements provide enhanced performance and efficiency compared to conventional FIB technologies. Below are the methods we use to focus plasma ion beams.

(i) Nonlinear demagnification

In plasma-based FIB systems, the plasma sheath near the ion extraction aperture plays a crucial role in beam performance. We observe that as the aperture size decreases below the plasma Debye length (~100 μm), electric field penetration through the extraction aperture increases nonlinearly. This effect induces a nonlinear demagnification factor, which shapes the ion emission surface and significantly reduces the beam size.

(ii) Micro-glass capillary guiding

We employ micro-glass capillaries to guide and focus ion beams with minimal losses. The guiding mechanism relies on charge redistribution on the capillary’s inner wall, induced by the incident beam. By applying external electric fields, we modulate the dynamics of these charge patches, surpassing the self-focusing limits of the capillary. This approach enables the formation of high-intensity nano-beams with precise trajectory control and enhanced beam stability.

Our work on nonlinear demagnification and capillary guiding represents significant progress in advancing plasma-based FIB systems for nanoscale applications.

B. Matter-Wave Phenomena of Plasma-Based Cryogenic Ion Beams

We explore the quantum behavior of plasma-based cryogenic ion beams by investigating their diffraction through free-standing material gratings. For this, we are developing a cryo-ion interferometer. The diffraction patterns in this setup exhibit high sensitivity to external electric and magnetic fields, as well as the properties of the grating material. These features will provide a unique platform to probe ion-matter interaction potentials at quantum scales. Furthermore, this sensitivity offers a pathway to developing advanced quantum sensors capable of achieving precision levels that surpass those of classical sensing technologies, with potential applications in fundamental physics and metrology.