GOALI: An Electrochemical Atomic Layer Deposition Process for Scalable Nanomanufacturing of On-chip Copper-based Interconnects

Case Western Reserve University, Cleveland OH

Investigators

Abstract

Advanced nanoelectronic circuits in microprocessors and memory devices utilize current-carrying copper interconnects. In modern devices, interconnect widths routinely approach a few tens of nanometers. However, the need for high interconnect packing density in high-performance computing drives a commensurate shrinking in the interconnect width in accordance with Moore's law. By the year 2020, interconnect widths are expected to shrink well below ten nanometers. A critical hurdle in driving such aggressive interconnect size reduction is the unavailability of an interconnect fabrication process with the following attributes: (i) Unprecedented atomic-level control needed to manipulate materials at the nanometer scale or below; and (ii) Ease of scale-up and integration with large-area substrates yielding reliable, low-cost manufacturability. This Grant Opportunity for Academic Liaison with Industry (GOALI) Program award will explore a novel approach towards nano-scale interconnect fabrication with the aforementioned attributes. This is critical for safeguarding Moore's law and for ensuring that the US semiconductor industry continues to maintain technological leadership in advanced nanoelectronics. This research will have broad impacts not just in the field of nanoelectronics, but also in many other areas central to the US economy and society, such as advanced energy systems and environmental remediation. In addition to enabling breakthroughs in scalable nanomanufacturing, this research will provide experiential engineering education and professional development to the next generation of scientists and engineers highly sought after by the US industry. The goal of the project is to study a novel electrochemical atomic layer deposition (e-ALD) process for the scalable nanomanufacturing of copper and copper-alloy interconnects. In spite of its enormous potential, state-of-the-art electrochemical atomic layer deposition of copper has not reached commercial viability primarily due to its low throughput, use of toxic metals, such as lead, and its inability to fabricate specific copper-alloys of relevance to nanoelectronic applications. To overcome these barriers, a 'one-step' lead-free electrochemical atomic layer deposition process will be investigated. Through fundamental characterization of the interplay between the electrode potential and the electrolyte chemistry, and through use of novel, environmentally benign electrolyte components, one-step deposition of copper and copper-alloy nano-films will be achieved. The project will eliminate a key technological roadblock in industrial-scale implementation of electrochemical atomic layer deposition technology for the metallization of nano-scale copper interconnects. An inter-disciplinary team of academic and industrial scientists will collaborate on the research through the exchange of knowledge in cutting-edge electrochemistry and advanced nanoelectronics.