Fluorine depleted adhesion layer for metal interconnect structure

A metal interconnect structure comprising:

• a fluorosilicate glass (FSG) layer located on a substrate;
• a fluorine-free silicate glass layer located on a recessed portion of said FSG layer, wherein said fluorine-free silicate glass layer is substantially free of fluorine;
• and
• a metal line abutting and embedded within said fluorine-free silicate glass layer, wherein said metal line is separated from said FSG layer by said fluorine-free silicate glass layer.

A method of forming a metal interconnect structure comprising:

• forming a fluorosilicate glass (FSG) layer having a first fluorine atomic concentration on a substrate;
• patterning a line trough and a via cavity within said FSG layer;
• forming a fluorine depleted silicate glass layer having a second fluorine atomic concentration on said fluorosilicate glass (FSG) layer, wherein said second fluorine atomic concentration is about 10% of, or less than 10% of, said first fluorine atomic concentration;
• and
• forming a metal line directly on said fluorine depleted silicate glass layer, wherein said metal line is separated from said FSG layer by said fluorine depleted silicate glass layer and is embedded in said fluorine depleted silicate glass layer.