Research Progress of Electroplated Nanotwinned Copper in Microelectronic Packaging

Area of Science:

• Materials Science
• Microelectronics Engineering
• Nanotechnology

Background:

• Copper is the standard interconnect material in microelectronics.
• Miniaturization of electronic devices leads to reliability issues with traditional copper interconnects.
• Nanotwinned copper (nt-Cu) emerges as a promising alternative material.

Purpose of the Study:

• To review the preparation, properties, and reliability of nanotwinned copper for microelectronic packaging.
• To highlight the advantages of nt-Cu over conventional copper in advanced applications.
• To provide a theoretical basis for the practical implementation of nt-Cu.

Main Methods:

• Summarization of existing research on nt-Cu properties, focusing on thermal stability and oxidation resistance.
• Review of electrolyte and electroplating processes for nt-Cu deposition on wafer substrates.
• Analysis of nt-Cu's performance in eliminating Kirkendall voids and controlling intermetallic compound formation.

Main Results:

• Nanotwinned copper exhibits superior thermal stability and oxidation resistance due to its (111) texture.
• Optimized fabrication processes allow for reduced transition layer thickness and improved pattern filling.
• nt-Cu effectively prevents Kirkendall voids and enhances solder joint reliability by controlling interfacial IMCs.
• Superior electromigration resistance and thermal cycling ability compared to ordinary copper.

Conclusions:

• Nanotwinned copper demonstrates significant potential for improving the reliability of microelectronic packaging.
• The unique properties of nt-Cu, particularly its (111) texture, address key challenges in miniaturized electronics.
• Further research and application of nt-Cu are warranted for next-generation electronic devices.