Directed self-assembly of silicon-containing block copolymer thin films

Area of Science:

• Materials Science
• Nanolithography
• Polymer Science

Background:

• Directed self-assembly (DSA) is a powerful technique for creating nanoscale patterns.
• Block copolymers (BCPs) are essential materials for DSA, enabling precise feature formation.
• Poly(styrene-block-trimethylsilylstyrene) (PS-PTMSS) is a silicon-containing BCP with high etch contrast.

Purpose of the Study:

• To achieve directed self-assembly of lamella-forming PS-PTMSS.
• To investigate the use of tailored top interfaces and patterned substrates for DSA.
• To evaluate the compatibility of DSA with Si-containing BCPs.

Main Methods:

• Utilized chemo- and grapho-epitaxy techniques.
• Employed hydrogen silsesquioxane (HSQ) based prepatterns on substrates.
• Applied tailored top interfaces and lithographically defined patterns.

Main Results:

• Achieved density multiplications up to 6× using chemo-epitaxy.
• Demonstrated trench space subdivisions up to 7× using grapho-epitaxy.
• Confirmed the necessity of a top coat neutral layer for PS-PTMSS orientation.

Conclusions:

• Successfully demonstrated DSA of PS-PTMSS with controlled orientation.
• Established the compatibility of DSA with high etch contrast, Si-containing BCPs.
• Validated the effectiveness of tailored interfaces and patterned substrates in DSA applications.