Imec and Tokyo Electron Demonstrate Electrical Advantages of Direct Cu Etch Scheme for Advanced Interconnects

Today, at the IEEE IITC conference, nano-electronics research center imec and Tokyo Electron Limited (TEL) presented a direct Cu etch scheme for patterning Cu interconnects. The new scheme has great potential to overcome resistivity and reliability issues that occur while scaling conventional Cu damascene interconnects for advanced nodes.

Aggressive scaling of damascene Cu interconnects leads to a drastic increase in the resistivity of the Cu wires, due to the fact that grain size is limited by the damascene trenches, which results in increased grain boundary and surface scattering. Additionally, the grain boundary negatively influences electromigration. When scaling damascene Cu interconnects, reliability issues occur because the overall copper volume is reduced and interfaces become dominant. Imec and TEL have demonstrated the feasibility of a direct Cu etch scheme to replace the conventional Cu damascene process. A key advantage of the direct Cu etch process is that it systematically results in larger grain sizes. Moreover, electromigration performance is preserved by applying an in-situ SiN cap layer that protects the Cu wires from oxidation and serves as the Cu interface.

Caption: Figure TEM section of copper etched lines encapsulated by SiN cap layer.

The results were achieved in cooperation with imec’s key partners in its core CMOS programs GLOBALFOUNDRIES, Inc., Intel Corp, Micron Technology, Inc., Panasonic Corporation, Samsung Electronics Co., Ltd.,, Taiwan Semiconductor Manufacturing Co., Ltd., SK hynix Inc., Fujitsu Semiconductor Ltd., and Sony Corporation.

About imec
Imec performs world-leading research in nanoelectronics. Imec leverages its scientific knowledge with the innovative power of its global partnerships in ICT, healthcare and energy. Imec delivers industry-relevant technology solutions. In a unique high-tech environment, its international top talent is committed to providing the building blocks for a better life in a sustainable society. Imec is headquartered in Leuven, Belgium, and has offices in Belgium, the Netherlands, Taiwan, USA, China, India and Japan. Its staff of about 2,200 people includes almost 700 industrial residents and guest researchers. In 2014, imec’s revenue (P&L) totaled 363 million euro. Further information on imec can be found at www.imec.be. Stay up to date about what’s happening at imec with the monthly imec magazine, available for tablets and smartphones (as an app for iOS and Android), or via the website www.imec.be/imecmagazine.
Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a “stichting van openbaar nut”), imec Belgium (IMEC vzw supported by the Flemish Government), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government), imec Taiwan (IMEC Taiwan Co.)and imec China (IMEC Microelectronics (Shanghai) Co. Ltd.) and imec India (Imec India Private Limited).


About Tokyo Electron Limited

As a leading global supplier of semiconductor and flat panel display (FPD) production equipment, Tokyo Electron Limited (TEL) engages in development, manufacturing, and sales in a wide range of product fields. All of TEL’s semiconductor and FPD production equipment product lines maintain high market shares in their respective global segments. TEL provides outstanding products and services to customers through a global network of approximately 80 locations in 16 countries in the U.S., Europe, and Asia. Further information on imec can be found at http://www.tel.com.