Passivation layer for integrated circuit structure and forming the same

An integrated circuit (IC) structure, comprising:

• a semiconductor substrate;
• a plurality of first metal lines laterally extending above the semiconductor substrate;
• a plurality of second metal lines laterally extending above the plurality of first metal lines, the plurality of second metal lines each having a thickness about five times greater than a thickness of a topmost one of the plurality of first metal lines;
• an oxide liner over the plurality of second metal lines;
• and
• a passivation structure over the oxide liner and having no interface therein.

An integrated circuit (IC) structure, comprising:

• a semiconductor substrate;
• an interconnect structure over the semiconductor substrate;
• a plurality of metal lines on the interconnect structure;
• a porous liner over the plurality of metal lines;
• a porous-free passivation layer over the porous liner;
• and
• a nitride layer over the porous-free passivation layer.