<p>➀ The semi-damascene technique, when combined with patternable metals like Ru, promises to achieve RC, area, cost, and power efficiency for interconnect scaling paths.</p><p>➁ The introduction of CU DUALdamascene in BEOL in 1997 marked a turning point in semiconductor history, shifting from subtractive Al patterning to wet processes like copper electroplating and CMP.</p><p>➂ Imec proposed a new metallization concept called 'semi-damascene' in 2020, which starts with direct patterning of the first local interconnect metal layer and then uses a single inlaid technique for the vias.</p>