Electroless processes for micro- and nanoelectronics

Electroless deposition of metals has many applications in micro- and nanotechnologies. Currently, electroless Cu, Co, Ni, Ag and their alloys are used as materials for interconnects and packaging applications for ultralarge-scale integration (ULSI) as well as for microelectro-mechanical systems (MEMS). Electroless methods offer high-quality ultrathin films that are compatible with high-resolution patterns such as sub-100 nm interconnects, contacts and via contacts for ULSI and in high aspect ratio structures for MEMS. In this paper, we present an overview of electroless methods for microtechnologies applications. We also present Cu, Ag, and Co alloys that are designed to improve performance and reliability of the pure metals. Next, we present new concepts of electroless deposition methods that will be useful for nanotechnologies. We explore the possibility to use electroless methods that can be combined with self-assembly of organic compounds such as proteins to form metallic interconnect network. Silver deposition on organic substrates is described as a novel approach to produce high-quality Ag coating on features with 1-10 nm critical dimensions. (C) 2003 Elsevier Ltd. All rights reserved.