Method for fabricating damascene structure using fluorocarbon film

A method for manufacturing an interconnect structure, the method comprising:

• providing a metal interconnect layer;
• forming a dielectric layer on the metal interconnect layer;
• forming a doped fluorocarbon layer on the dielectric layer;
• forming a patterned hardmask layer on the doped fluorocarbon layer, wherein the patterned hardmask layer comprises:
• a first hardmask layer comprising non-porous SiOCH on the doped fluorocarbon layer;
• a second hardmask layer comprising TEOS on the first hardmask layer;
• a third hardmask layer comprising TiN on the second hardmask layer;
• etching the doped fluorocarbon layer and the dielectric layer using the patterned hardmask layer as a mask to form a trench in the dielectric layer and a through-hole through the dielectric layer to the metal interconnect layer;
• forming a metal layer filling the trench and the through-hole;
• and
• planarizing the metal layer until the planarized metal layer has an upper surface that is flush with an upper surface of the doped fluorocarbon layer.