In the relentless pursuit of smaller, faster, and more efficient semiconductor devices, researchers are constantly seeking innovative solutions to overcome the technical hurdles that accompany Moore’s Law. One such challenge is the need for advanced contact metals that can keep pace with the increasing demands of large-scale integration devices. Enter cobalt (Co), a promising candidate poised to replace tungsten in next-generation technologies.
Ganggyu Lee, a researcher from the Department of Energy Engineering at Hanyang University in Seoul, South Korea, has been at the forefront of this exploration. His recent study, published in the journal MetalMat (translated from Korean as “Metal Materials”), delves into the role of oxidation states in cobalt chemical mechanical planarization (CMP), a critical process in semiconductor manufacturing.
CMP is a process used to planarize and polish surfaces to achieve ultra-smooth finishes, essential for the performance of semiconductor devices. However, achieving low surface roughness with cobalt has been hindered by its low removal rate during CMP. Lee’s research addresses this issue by designing a cobalt oxide layer with unique properties that enhance CMP performance.
“The key to our approach is controlling the physicochemical properties of the cobalt oxidant,” Lee explains. By manipulating the reduction potential and diffusion coefficient of the oxidant, Lee and his team were able to create a cobalt oxide layer with a dominant oxidation state of Co (II), an amorphous phase, and a thin thickness. This design significantly improved CMP performance, increasing the removal rate by 254% and reducing surface roughness by 41% compared to conventional methods using H2O2.
The implications of this research are substantial for the semiconductor and energy sectors. As devices continue to shrink and demand for high-performance electronics grows, the need for advanced materials like cobalt becomes ever more critical. Lee’s findings could pave the way for more efficient and cost-effective manufacturing processes, ultimately driving innovation in various applications, from consumer electronics to renewable energy technologies.
“This research not only addresses a critical challenge in semiconductor manufacturing but also opens up new possibilities for the use of cobalt in advanced technologies,” Lee notes. The study’s insights into the oxidation behavior of cobalt and its impact on CMP performance provide a foundation for future developments in the field.
As the industry continues to push the boundaries of what’s possible, research like Lee’s serves as a reminder of the power of innovation and the importance of understanding the fundamental properties of materials. With the semiconductor industry’s relentless march toward smaller and more powerful devices, the insights gained from this study could play a pivotal role in shaping the future of technology.