In situ UV nano-imprint lithography alignment using high contrast mark

Area of Science:

• Nanofabrication
• Lithography
• Optical Metrology

Background:

• UV imprint lithography requires precise alignment for micro/nanofabrication.
• Existing alignment methods struggle with Moiré fringe contrast due to imprint resist interference.

Purpose of the Study:

• To design and fabricate high contrast alignment marks for improved in situ alignment in UV imprint lithography.
• To overcome the challenge of reduced Moiré fringe quality caused by imprint resist within patterns.

Main Methods:

• Rigorous coupled-wave analysis (RCWA) simulations were employed for mark design and optimization.
• Fabrication of the designed high contrast alignment marks.
• Experimental testing on an imprint alignment system.

Main Results:

• Simulations successfully guided the design of alignment marks that enhance Moiré fringe quality.
• Fabricated marks demonstrated feasibility and effectiveness in experimental tests.
• The designed marks effectively mitigate the contrast deterioration caused by imprint resist.

Conclusions:

• The developed high contrast alignment marks are effective for UV imprint lithography.
• RCWA simulations provide a reliable approach for optimizing alignment mark design.
• This work enables more accurate and reliable in situ alignment in imprint processes.