Cycloalkyl Ligand-Engineered Zirconium-Oxo Clusters for Sub-9 nm Electron Beam Lithography with Ultralow Line Edge...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Photoresists are critical for semiconductor manufacturing, dictating lithography accuracy and device quality.
• Achieving sub-10 nm line width (LW) with line edge roughness (LER) below 2 nm is a key challenge for next-generation semiconductor fabrication.

Purpose of the Study:

• To explore cycloalkyl ligand engineering of carboxylic acid-modified zirconium-oxo clusters (Zr₆O₈) for improved lithographic performance.
• To investigate the structure, processability, and electron beam lithography (EBL) capabilities of these modified clusters.

Main Methods:

• Systematic screening of four cycloalkanecarboxylic acid ligand-modified Zr₆O₈ samples.
• Evaluation of solubility, processability, structural characterization, and lithographic performance under EBL.

Main Results:

• Cyclopropanecarboxylic acid modification resulted in insufficient solubility.
• Cyclobutanecarboxylic acid modification yielded an oily product, hindering characterization.
• Cyclohexanecarboxylic acid modification showed low EBL sensitivity.
• Cyclopentanecarboxylic acid-modified Zr₆O₈ produced crystalline solids and achieved 8.65 nm LW with 1.28 nm LER.

Conclusions:

• Cycloalkyl ligand engineering effectively tunes the lithographic performance of Zr₆O₈ clusters.
• Cyclopentanecarboxylic acid-modified Zr₆O₈ offers a promising platform for next-generation nanolithography.
• This strategy provides a viable route for designing high-Z metal-oxo cluster photoresists for high-resolution patterning.