METHODS OF FORMING DUAL-DAMASCENE INTERCONNECT STRUCTURES ON SEMICONDUCTOR SUBSTRATES USING MULTIPLE PLANARIZATION LAYERS HAVING DIFFERENT POROSITY CHARACTERISTICS

摘要

A method of forming a dual-damascene interconnection structure on a semiconductor substrate using multiple planarization layers having different porosity characteristics is provided to remove residues of the planarization layers within a via hole by using the multiple planarization layers having different porosity characteristics. An electrical insulating layer(100) is formed on a substrate. One or more via holes are formed in a part of the electrical insulating layer. At least one via hole is filled with a first electrical insulating material having a first porosity characteristic. The via hole filled with first electrical insulating material is covered with a second electrical insulating material layer(106) having a second porosity characteristic lower than the first porosity characteristic. A first part of the first insulating material within the via hole is exposed by etching back the second electrical insulating material, selectively. A trench for exposing a second part of the first insulating material within the via hole is defined by etching back the electrical insulating layer, selectively. The first electrical insulating material is removed from the via hole.