Microelectronic Interconnect Materials Division

　　Since invention of the transistors by John Bardeen, William B. Shockley, and Walter Brattain in 1948, microelectronics industry has seen many years of explosive growth and become a major force impacting global social and economical changes. A recent estimate by the central intelligence agency places the microelectronics industry at the very top of the list of industrial outputs in contributing to the gross world production. From space exploration to personal entertainment, microelectronic products are now an essential and integral part of our life.

　　The central function of an electronic device is to process electronic signals. Within each device, electronic signals are transmitted by the interconnects from one part to another for processing. These interconnects may consist of conductive lines, pads, vias, wires and joints that form interconnected networks (Figure). Signal transmission along the interconnects has become increasingly important in limiting the speed, the size, the functionalities, and the reliability of modern microelectronic devices.

　　Early devices use highly conductive metals such as aluminum and copper (Figure) as the interconnect materials. In recent years, more integration and performance demands have required use of the alloys of copper, silver, tin, gold, zinc and nickel to form interconnects at various levels of the device. The performance of the interconnect becomes strongly dependent on the composition, microstructure, processing and service condition of the interconnect alloys.

　　The objective of our research has been to elucidate the materials science basis for understanding the relationship of the interconnect properties with the composition, structure, processing and service condition of interconnect materials. Such understanding will provide the basic guidelines for design of better interconnect materials and structures.