Dielectric between metal structures and method therefor

摘要

Two conductors of the same layer are separated by a low-K dielectric to minimize capacitance between them. The first and second conductors may have sidewalls with conductive barriers. The conductive barriers are separated from the low-K dielectric by spacers. The dielectric spacers have a top portion and a lower portion in which the top portion may have a higher dielectric constant than the lower portion or may be the same material. The two conductors are formed in trenches in a convenient dielectric. Prior to forming the conductors, the conductive barriers are deposited in the trench. After the conductors are formed, the convenient dielectric is removed. The dielectric spacers are formed adjacent to the conductive barriers. The low-K dielectric is then deposited adjacent to the dielectric spacers and not in contact with the conductive barriers.