Liquid-Phase Deposition of Freestanding Copper Foils and Supported Copper Thin Films and Their Structuring into Conducting Line Patterns

摘要

Copper plays a fundamental role in electronics. The low bulk electrical resistivity, high thermal conductivity, good machining and joining properties, and high availability lead to the situation that more than 60 % of all copper is processed in the electrical industry. Inventions such as the telegraph, telephone, and radio around 1900 laid the foundation for the origin of the printed circuit board (PCB) with copper as trace material. In the 1960s, the PCB itself inspired the creation of the integrated circuit (IC), and it was in the 1990s when the breakthrough of copper as interconnecting material hit the microelectronic research and development community. The preferential usage of copper as trace and interconnecting material in microelectronics is primarily based on its high bulk electrical conductivity and higher resistance against electromigration compared to the alternative material aluminum.