Cutting-Edge Trench Microcapacitor Enhances Chip Power Efficiency

Researchers in the US have made a significant breakthrough by developing a microcapacitor that can be seamlessly integrated into chips as a 3D trench to provide power. The team at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley has achieved remarkable energy and power densities in a microcapacitor constructed with engineered thin films of hafnium oxide and zirconium oxide.

This innovative approach utilizes materials and fabrication techniques already prevalent in chip manufacturing to create a microcapacitor with exceptional performance metrics. The microcapacitor boasts nine times higher energy density and an impressive 170 times higher power density, measuring at 80 mJ/cm2 and 300 kW/cm2, respectively.

“We’ve demonstrated the ability to store a substantial amount of energy in a microcapacitor composed of engineered thin films, surpassing the limitations of traditional dielectrics,” stated Sayeef Salahuddin, the Berkeley Lab faculty senior scientist and UC Berkeley professor leading the project. “Moreover, we are achieving this with a material that can be directly processed on top of microprocessors.”

The thin films of HfO2-ZrO2 have been meticulously engineered to exhibit a negative capacitance effect, a phenomenon that enhances overall capacitance when one of the dielectric layers possesses negative-capacitance properties. By leveraging this effect, the researchers were able to store larger amounts of charge, showcasing the potential for groundbreaking advancements in microelectronics.

By carefully tuning the composition of the crystalline films, the team managed to strike a delicate balance that leverages the negative capacitance effect. This delicate equilibrium allows the material to be easily polarized by even a small electric field, leading to the efficient storage of charge. The integration of atomically thin layers of aluminum oxide further enhanced the energy storage capability of the films, enabling them to reach up to 100 nm in thickness while maintaining desired properties.