Atomic layer deposition for spacer defined double patterning of sub-10 nm titanium dioxide features

Area of Science:

• Materials Science
• Nanotechnology
• Data Storage

Background:

• Next-generation hard disk drives require data storage densities beyond 5 Tb/in².
• Achieving these densities necessitates single-bit patterning of features with sub-10 nm dimensions using nanoimprint lithography.
• Master templates for sub-10 nm lithography are fabricated using pattern multiplication with atomic layer deposition (ALD).

Purpose of the Study:

• To investigate silicon dioxide and titanium dioxide as pattern spacer materials for sub-10 nm lithography.
• To understand the interactions between these oxide spacers and common materials like carbon, chromium, and silicon dioxide.
• To demonstrate pattern doubling with sub-10 nm features using optimized spacer fabrication.

Main Methods:

• Studied the use of silicon dioxide and titanium dioxide as pattern spacers.
• Investigated material interactions using atomic layer deposition (ALD).
• Employed self-assembled block copolymer lithography for pattern generation.

Main Results:

• Thermal titanium dioxide ALD enabled conformal spacer deposition without damaging the carbon mandrel.
• This method eliminated surface modification issues caused by metal-organic precursor reactivity.
• Demonstrated pattern doubling, achieving 7.5 nm half-pitch spacer features.

Conclusions:

• Thermal titanium dioxide ALD is a viable method for fabricating conformal spacers in sub-10 nm lithography.
• This approach is crucial for advancing hard disk drive technology towards higher storage densities.
• The study successfully demonstrated pattern doubling at the 7.5 nm scale.