A streamlined set-up for Lloyd's mirror interference lithography, using a single-mode-fibre-coupled laser

Area of Science:

• Nanofabrication
• Optical Lithography
• Laser Technology

Background:

• Traditional laser interference lithography (LIL) setups often require complex alignment procedures.
• Free-space lasers and spatial filters add to the complexity and cost of LIL experiments.

Purpose of the Study:

• To develop a simplified and cost-effective setup for Lloyd's-mirror-based laser interference lithography (LM-LIL).
• To demonstrate the preparation of high-resolution one- and two-dimensional arrays using the streamlined system.

Main Methods:

• Utilized a fibre-coupled single-frequency laser (SFL) as the light source, eliminating the need for manual beam alignment.
• Employed a simple optical configuration consisting of the SFL, a plane mirror, and an optional half-wave plate.
• Detailed step-by-step procedures for sample preparation, exposure, and processing were provided.

Main Results:

• Achieved pitches down to the sub-220-nm level using a 405-nm laser.
• The simplified setup proved to be inexpensive, robust, and easy to use.
• Successfully fabricated one- and two-dimensional periodic arrays.

Conclusions:

• The streamlined LM-LIL setup significantly simplifies experimental implementation.
• This method offers a practical and accessible approach for nanoscale pattern fabrication.
• The system is suitable for preparing high-density periodic structures for various applications.