Development-free grayscale electron beam lithography on poly (methyl methacrylate).

Area of Science:

• Materials Science
• Nanotechnology
• Additive Manufacturing

Background:

• Conventional electron beam lithography (EBL) methods for grayscale exposure often result in roughness and poor continuity.
• Direct fabrication of 3D structures with high resolution remains a challenge.

Purpose of the Study:

• To present and validate a novel method for direct 3D structure fabrication on poly(methyl methacrylate) (PMMA) membranes.
• To achieve precise control over the depth resolution of fabricated structures.
• To improve the quality and reduce processing steps compared to conventional EBL methods.

Main Methods:

• Utilizing grayscale electron beam lithography (EBL) for direct 3D structure fabrication.
• Implementing precise control of exposure dose for depth resolution.
• Employing a development-free approach.
• Investigating differences between 2D and 3D proximity effect correction.
• Proposing a dose correction method based on height differences.

Main Results:

• Demonstrated precise control of depth resolution to less than 1 nm.
• Achieved a development-free fabrication process, reducing processing steps.
• Minimized excessive roughness and poor continuity issues.
• Determined differences in proximity effect correction for 2D and 3D structures.
• Showcased increased edge steepness of fabricated structures using the proposed dose correction method.

Conclusions:

• The validated grayscale EBL method enables high-resolution, direct 3D structure fabrication on PMMA.
• The development-free approach and dose correction enhance fabrication efficiency and structural integrity.
• This method offers a promising advancement for nanoscale 3D patterning.