New block copolymer achieves 7.6 nm line width

A just lately developed block copolymer may assist push the bounds of integration and miniaturization in semiconductor manufacturing, report scientists at Tokyo Institute of Expertise (Tokyo Tech) and Tokyo Ohka Kogyo (TOK). Chemically tailor-made for dependable directed self-assembly, the proposed compound can organize itself into perpendicular lamellar buildings whose half-pitch width is lower than 10 nanometers, outperforming typical and extensively used block copolymers.

Miniaturization is likely one of the basic qualities of recent electronics and is essentially answerable for the unbelievable increments in efficiency witnessed over the previous many years. To maintain this momentum going, it’s needed to realize circuit patterns finer than the prevailing ones on semiconductor chips, that are an important a part of all digital gadgets.

Some specialists estimate that, by 2037, the smallest distance between options in semiconductor gadgets, referred to as “half-pitch,” will have to be as small as 8 nm to assist next-generation electronics, emphasizing the necessity for developments in lithographic processes (technique of making extremely advanced circuit patterns on semiconductor components).

As one would count on, creating such finely detailed buildings on any type of materials is an enormous enterprise. One promising avenue to realize this feat is named directed self-assembly (DSA) with block copolymers (BCPs).

Merely put, BCPs are lengthy chain-like molecules made out of two or extra distinct sections—or blocks— of polymers. The method of DSA entails exploiting the interactions between completely different blocks in BCPs in order that they spontaneously and constantly organize themselves into ordered buildings and patterns.

Whereas this technique is actually highly effective, producing options smaller than 10 nanometers (sub-10 nm) utilizing DSA stays difficult.

In a examine printed on 6 July 2024 in Nature Communications, researchers from Tokyo Tech and TOK managed to push the envelope of the probabilities on this area.

Led by Professor Teruaki Hayakawa, the analysis group developed a novel BCP that was rigorously tailored to create extremely small line patterns on a substrate within the type of lamellar domains (a construction composed of nice and various layers). These tiny patterns may pave the way in which for brand spanking new superior semiconductor gadgets.

The newly developed BCP was created from polystyrene-block-poly(methyl methacrylate) (or PS-b-PMMA), a consultant and extensively studied BCP for DSA. First, the researchers launched an applicable quantity of poly(glycidyl methacrylate) (PGMA) into PS-b-PMMA, acquiring PS-b-(PGMA-r-PMMA).

Subsequent, they modified the PGMA phase with completely different thiols, aiming to refine the repulsive interactions between the completely different blocks within the ensuing polymer, named PS-b-PG_FM. The PS and PMMA segments additionally managed the affinity of the completely different components of the molecule for air, which performs an vital function in its self-alignment course of throughout DSA.

The tailor-made BCP reliably self-assembled into exceptionally small nanometric lamellar buildings when utilized as a skinny movie, as confirmed by atomic power microscopy. Furthermore, this new compound displayed spectacular efficiency on a substrate with parallel polystyrene chemical guides.

“Skinny-film aligned lamellar domains with a vertical orientation may very well be reliably and reproducibly obtained through directed self-assembly, yielding parallel line patterns that correspond to a half-pitch dimension of seven.6 nm,” says Hayakawa. It’s value mentioning that this is likely one of the smallest half-pitch sizes reported worldwide for thin-film lamellar buildings and not using a prime coating.

General, these thrilling findings have the potential to advance cutting-edge applied sciences in semiconductor manufacturing.

“PS-b-PG_FM BCPs are promising templates to be used in lithography as a result of they will produce nice patterns in DSA processes much like those used for typical PS-b-PMMA, with the potential to outperform them,” concludes Hayakawa.

“Research aimed toward optimizing the pattern-transfer processes utilizing line patterns in PS-b-PG_FM skinny movies as templates will probably be investigated sooner or later,” he provides.