Patent ID: 9142508
Filing Date: 2015-09-22
Classification: H01L

Abstract:
1. A method of fabricating a damascene structure with a single exposure, comprising: forming a pre-metal first layer of dielectric material on a surface of a substrate, the substrate comprising a region of semiconductor material, the first layer having a thickness in a direction projecting above the surface; forming a pre-metal second layer of dielectric material on the first layer; patterning a lithographic mask over the second layer; removing material from the second layer to form one or more second cavities using the lithographic mask; removing material from the first layer using the lithographic mask to form one or more first cavities which are open to the one or more second cavities, the first cavities extending through the thickness of the first layer so as to expose portions of the surface of the substrate, wherein the removing of the material from the first layer is performed at a different rate than the removing of the material from the second layer, and wherein the removing of the material from the first layer is performed such that the one or more first cavities have a width different from a width of the one or more second cavities open thereto, the widths being in a first direction; forming a coating including at least one of a seed layer or a barrier layer, the coating contacting walls of one of more of the second cavities and walls of one or more of the first cavities which are open to the one or more first cavities, the coating contacting one or more of the portions of the surface exposed within the one or more first cavities; and forming a conductor in the one or more of the first cavities and in the one or more of the second cavities open thereto, wherein a width of the conductor in the one or more first cavities in the first direction is different from a width of the conductor in the one or more second cavities in the first direction; wherein the removing of the first and second layers comprises wet etching, wherein the removing of material of the second layer is more isotropic than the removing of material of the first layer.