Ion mass and energy selective hyperthermal ion-beam assisted deposition setup

Area of Science:

• Materials Science and Engineering
• Plasma Physics and Chemistry
• Thin Film Deposition Technologies

Background:

• Ion-beam assisted deposition (IBAD) is crucial for high-quality thin film synthesis, offering control over film properties.
• Conventional IBAD methods using broad-beam ion sources lack precise control over ion mass and kinetic energy distributions.
• Hyperthermal ion energies (1-100 eV) are increasingly important for film growth and preparative mass spectrometry.

Purpose of the Study:

• To present a compact experimental setup for independently controlling ion mass and kinetic energy in the hyperthermal energy range.
• To demonstrate the capability of separating different ion species, such as nitrogen ions (N+ and N2+).
• To validate the setup's suitability for advanced thin film deposition, including epitaxial growth.

Main Methods:

• Utilized a constricted glow-discharge plasma beam source coupled with a custom quadrupole system and ion optics.
• Achieved mass separation of monoatomic (N+) and polyatomic (N2+) nitrogen ions.
• Demonstrated tunable kinetic energy selection for separated ion species within the hyperthermal range.

Main Results:

• Successfully separated monoatomic and polyatomic nitrogen ions, controlling their kinetic energies.
• Achieved ion current densities of approximately 1 μA/cm² with a beam profile FWHM of ~10 mm at the sample.
• Successfully deposited epitaxial Gallium Nitride (GaN) films for the first time using the developed setup.

Conclusions:

• The presented setup offers independent control over ion mass and hyperthermal kinetic energy, overcoming limitations of traditional IBAD.
• The capability to deposit epitaxial GaN films highlights the potential for fundamental studies on ion-substrate interactions in thin film growth.
• This technology enhances the flexibility and precision of ion-beam assisted deposition processes.