Researchers find way to cut overheating of semiconductors

The demand to decrease the size of semiconductors coupled with the problem of heat generated at the hot spots of the devices not being effectively dispersed has negatively impacted the reliability and durability of modern devices. Researchers from the Korea Advanced Institute of Science and Technology (KAIST) have found a new way of dispersing heat by using surface waves generated on the thin metal films over the substrate.

KAIST President Kwang Hyung Lee announced that Professor Bong Jae Lee’s research team succeeded in measuring a newly observed transference of heat induced by ‘surface plasmon polariton’ (SPP) in a thin metal film deposited on a substrate. Surface plasmon polariton (SPP) refers to a surface wave formed on the surface of a metal as a result of strong interaction between the electromagnetic field at the interface between the dielectric and the metal and the free electrons on the metal surface, along with similar collectively vibrating particles.

The research team utilised SPPs, which are surface waves generated at the metal–dielectric interface, to improve thermal diffusion in nanoscale-thin metal films. Since this heat transfer mode occurs when a thin film of metal is deposited on a substrate, it is highly usable in the device manufacturing process and can also be manufactured over a large area. The researchers showed that the thermal conductivity increased by about 25% due to surface waves generated over a 100 nm-thick titanium (Ti) film with a radius of about 3 cm.

Bong Jae Lee said the new heat transfer mode can be applied as a nanoscale heat spreader to efficiently dissipate heat near the hot spots for easily overheatable semiconductor devices. “The significance of this research is that a new heat transfer mode using surface waves over a thin metal film deposited on a substrate with low processing difficulty was identified for the first time in the world,” Lee said.

The result has great implications for the development of high-performance semiconductor devices, as it can be applied to rapidly dissipate heat on a nanoscale thin film. This new heat transfer mode is also expected to solve the problem of thermal management in semiconductor devices as it enables more effective heat transfer at nanoscale thickness while the thermal conductivity of the thin film usually decreases due to the boundary scattering effect.

This study was published online in Physical Review Letters.

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