Three different aluminum reactive ion etch (RIE) processes have been developed for manufacturing 175 and 150 nm line/space wiring patterns in multilevel interconnection. The three approaches vary in complexity: (1) Conventional organic antireflective coating (ARC) with a photoresist etch mask, (2) inorganic silicon oxynitride dielectric ARC with a photoresist etch mask, and (3). a physical vapor deposition tungsten cap layer used as a hardmask. The reliability performance for the 150 nm Al RIE lines scales with previous technologies at larger groundrules. The process windows for each key parameters are evaluated. It is also shown that the metal etch processes can be extended to even smaller ground rules with a line or space width to height aspect ratio as high as 5 without requiring a new tool set.