Fabrication of Al microspheres by utilizing electromigration

Area of Science:

• Materials Science
• Nanotechnology
• Physics

Background:

• Electromigration is a phenomenon where atoms move under the influence of an electric field.
• Fabricating micro/nanostructures often requires precise control over material deposition and assembly.
• Surface tension plays a critical role in the formation of spherical structures.

Purpose of the Study:

• To develop a novel method for fabricating aluminum microspheres.
• To investigate the role of electromigration in micro-sphere formation.
• To determine the optimal conditions for creating uniform aluminum microspheres.

Main Methods:

• Utilizing electromigration in a passivated aluminum line with a slit.
• Inducing high current density and substrate temperature to accumulate aluminum atoms.
• Releasing accumulated atoms from pre-introduced holes in the passivation layer.
• Leveraging surface tension for microsphere formation.

Main Results:

• Successfully fabricated aluminum microspheres with diameters ranging from 4-7 micrometers.
• Demonstrated that microsphere formation is dependent on a specific temperature range at the anode end.
• Observed atom accumulation before a slit in the passivated line due to high current density.

Conclusions:

• Electromigration is an effective technique for fabricating aluminum microspheres.
• The process requires precise control over temperature and current density.
• Surface tension is crucial for achieving spherical morphology in the fabricated structures.