Semiconductor Manufacturing Research News
Sugar Aids DSA Copolymers
A team based at the Centre de Recherches sur les Macromolécules Végétales (CNRS) said it has combined sugar- and oil-based polymers in an effort to improve the resolution of patterns created with self-assembling copolymers.
Synthetic polymers derived from petroleum have a minimum resolution of about 20nm, according to CNRS. Associating sugars with oil-based macromolecules may reduce the resolution of the self-organization films to 5-nm, according to an article in the journal ACS Nano. The copolymers could be applied to flexible electronics, including biosensors and photovoltaic cells, said Redouane Borsali, a CNRS senior researcher.
The hybrid material combines sugar-based and petroleum-derived polymers with widely different physical/chemical characteristics, creating sugar cylinders within a petroleum-based polymer lattice. The ACS Nano article bears the title Oligosaccharide/Silicon-Containing Block Copolymers with 5 nm Features for Lithographic Applications.
Purposeful Cracking
South Korean researchers published a paper in Nature describing efforts to cause purpose-driven cracking, a method which they said could be applied to creating channels in electronic devices and microfluidic products.
The team borrowed methods used for fashioning stone, in which small holes are made in a piece of stone and wood is inserted. Soaking the wood causes the stone to expand and crack in a controlled fashion.
Doing that in semiconductor materials produced patterns such as spirals, oscillating and branched fracture paths, and fractal geometries.
Controlled cracking may work for creating channels. (Source: Nature)
The team worked with a silicon nitride thin film deposited on a silicon substrate using low-pressure chemical vapor deposition. Micro-notches etched into the silicon substrate concentrated stress for crack initiation, which occurred spontaneously during deposition of the silicon nitride layer.
The Korean team said the patterning technique “presents new opportunities in nanofabrication and offers a starting point for atomic-scale pattern formation, which would be difficult even with current state-of-the-art nanofabrication methodologies.”
Throwaway Touch Pads
Capacitors can be cut into metallic paper, forming touch keys.
A U.S.-French team described ways to make touch pads so cheaply that they could be applied to disposable products such as disposable medical device labels and food labels, or for keying in password-protected codes on security-sensitive packaging.
The electronic touch pads, which might cost as little as 25 cents per square meter, are made of paper coated in aluminum and transparent polymer, forming the basis for touch-sensitive capacitors. Lead researcher Aaron Mazzeo of Harvard University said a laser could cut individual capacitors into the paper, each corresponding to a key on a touch pad. The keys would need to be linked to an external source of power and to electronic circuitry to detect when a given key is touched. That work remains to be done, according to an article in Chemistry World.
– by David Lammers
Tags: directed self assembly, displays, DSA, lithography, touch pads