Air gap between tungsten metal lines for interconnects with reduced RC delay

A method of forming a semiconductor device, the method comprising:

• forming two or more Tungsten lines in a first layer of an integrated circuit;
• forming at least one air gap between at least two of the Tungsten lines;
• coupling an interposer to the integrated circuit;
• and
• attaching a laminated package substrate to the interposer, wherein the interposer absorbs mechanical stress induced by mismatch in coefficient of thermal expansion (CTE) between the laminated package substrate and the interposer, and protects the at least one air gap from the mechanical stress.

A semiconductor device comprising:

• two or more Tungsten lines in a first layer of an integrated circuit;
• means for forming at least one air gap between at least two of the Tungsten lines;
• coupling means coupled to the integrated circuit;
• and
• a laminated package substrate attached to the coupling means, wherein the coupling means comprises means for absorbing mechanical stress induced by mismatch in coefficient of thermal expansion (CTE) between the laminated package substrate and the coupling means, and means for protecting the at least one air gap from the mechanical stress.