A simple spin process makes foldable semiconductors. POSTECH's team expects fabrication costs to fall to one-tenth and extremely low power consumption to open possibilities such as laptops operating a month on one charge. They describe the development as the first nonvolatile-memory semiconductor technology of its kind to reach a potentially commercializable level.
By simply depositing a solution and spinning it, a Korean team has developed foldable semiconductors for electronic paper and foldable or wearable computers. Professors Oh-Hyun Kim (Electrical Engineering), Su-Moon Park (Chemistry) and Moonhor Ree jointly developed a new plastic material for nonvolatile memory and successfully fabricated high-performance devices.
The technology, to be reported on the 15th in Advanced Materials, uses hyperbranched copper phthalocyanine (HCuPc), a polymer with copper phthalocyanine (CuPc) monomers, previously used in semiconductor devices. It uses write-once-read-many (WORM) storage, changing thin-film conductivity according to voltage and current to write and read information.
The polymer allows active layers of the desired thickness to be formed by simple spin coating, simplifying fabrication and potentially lowering production costs to one-tenth. Conventional chemical vapor deposition is costly because chemicals must adsorb and grow on the substrate.
The devices process signals and information in tens of nanoseconds and operate below 1.0 volt. The researchers said their low power use could enable laptops lasting a month on a single charge. The new plastic is lightweight, easily bent and suitable for dense three-dimensional integration, with prospects in foldable electronic newspapers, books and notebooks, flexible screens, and foldable or wearable computers.
Ree said this nonvolatile memory field is still in its infancy worldwide. He said the team was first to reach a potentially commercializable level and that the semiconductor industry was watching because the technology represents post-flash memory capable of overcoming flash limitations in speed and capacity. The team had also reported a new high-performance nonvolatile-memory plastic in Advanced Functional Materials the previous August.
Spin coating: Thin-film formation from a solution using centrifugal force. Chemical vapor deposition: A process used in integrated-circuit manufacturing to deposit thin films such as silicon. Heat, light or radio-frequency plasma activates precursor gases so that materials adsorb and accumulate on a substrate.
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