A novel bottom-up Ag contact (30nm diameter and 6.5 aspect ratio) technology by electroplating for 1Xnm and beyond technology

Very high 6.5 aspect ratio, 30nm diameter contacts are filled with a novel bottom-up Ag electroplating technology for the first time. The technology utilizes two distinct advantages of Ag over Cu: (1) Ag has the lower metal resistivity, and (2) Ag has several orders of magnitude lower diffusivity in Si than Cu. The bottom-up deposition technology intrinsically avoids the issue of seam formation arising from sidewall deposition, and thus is very promising” for future scaled contacts, even down to single digit nano-meter technology nodes.