Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal using a direct electric current. The part to be coated acts as the cathode (negative electrode) of an electrolytic cell; the electrolyte is a salt solution of the metal to be coated; and the anode (positive electrode) is usually a consumable metal, which will generate the metal ions into the electrolyte.
Given the rapid development of the electronics industry, it was inevitable that the design of electronic products would evolve toward small size, low power consumption, and high reliability. More than 30 years ago, electroplating was introduced for copper deposition at nodes of 130nm and lower to reduce resistivity between metal lines and enhance resistance to electromigration. For IC dual-damascene applications, the copper metal plating is product-dependent and has a major impact on yield and reliability. Major process features include deposition rate, final metal thickness, and metal thickness uniformity. Areas where the process must be controlled are around the film properties such as defects and impurities to ensure an excellent electrochemical plating (ECP) process.
In 1998, ACM Research Inc. started research and development of ECP technology. Building on this technology, the company next invented the Ultra ECP map, configured with ACM’s exclusive multi-anode partial-plating function. This allows the deposition of the copper metal layer on a dual-damascene structure, which is compatible for 55nm/40nm/28nm/14nm applications and beyond in IC mass production.
ACM has numerous patents, both awarded and pending, in many areas of plating technology, such as multizone anodes for superior uniformity control, rubber-seal plating chucks for superior sealing, and partial pulse plating for pattern structure filling. ACM’s Ultra ECP 3d platform, Ultra ECP ap platform, and Ultra ECP GIII plating tool were developed for 3D through-silicon via (TSV), advanced packaging, and compound semiconductor metal layer deposition applications.