Dual damascene process flow for a deep sub-micron technology

摘要

A process for forming a dual damascene opening, in a composite insulator layer, comprised of an overlying, wide diameter opening, used to accommodate a metal interconnect structure, and comprised of an underlying, narrow diameter opening, used to accommodate a metal via structure, has been developed. The process features the use of conventional photolithographic and anisotropic dry etching procedures, used to create an initial dual damascene opening, in the composite insulator layer. The subsequent formation of insulator spacers, on the vertical sides of the initial dual damascene opening, however, results in a final dual damascene opening, featuring a diameter smaller than the diameter displayed with the initial dual damascene opening.