High-speed maskless nanolithography with visible light based on photothermal localization.

Area of Science:

• Materials Science
• Nanotechnology
• Laser Physics

Background:

• Maskless lithography is crucial for micro- and nanofabrication.
• Existing laser writing methods face limitations in speed and resolution.
• AgInSbTe thin films are promising materials for optical data storage and nanophotonics.

Purpose of the Study:

• To experimentally demonstrate high-speed maskless nanolithography on AgInSbTe thin films.
• To investigate the underlying mechanism for enhanced resolution and speed.
• To explore the tunability of writing resolution.

Main Methods:

• Utilized a GaN diode laser (405 nm) for lithography in air at room temperature.
• Processed large-area (120 mm diameter) AgInSbTe thin film samples.
• Analyzed feature width, lithography speed, and laser power dependency.

Main Results:

• Achieved feature widths of 46 ± 5 nm, significantly below the diffraction limit.
• Reached high lithography speeds of 6–8 m/s, tens of times faster than conventional methods.
• Demonstrated instantaneous tunability of writing resolution by adjusting laser power.

Conclusions:

• The breakthrough is attributed to the photothermal localization response, concentrating heat to a spot smaller than the light spot.
• This phenomenon enables unprecedented resolution and speed in laser-based nanolithography.
• The findings open new avenues for advanced nanofabrication techniques.