Semiconductor device with air gap and method of manufacturing the semiconductor device

A method comprising:

• forming a metal line pattern on a metal substrate, the metal line patterning including a plurality of metal lines spaced apart by a plurality of recesses;
• forming a plurality of directed-self aligned (DSA) segments respectively in the plurality of recesses, the DSA segments including block co-polymer (BCP);
• performing a phase separation process on the plurality of DSA segments to form, in each of the plurality of recesses, two first polymer blocks on sidewalls of two of the plurality of metal lines that border the recess, and a second polymer block sandwiched between the two first polymer blocks;
• removing, with respect to each of the recesses, the second polymer block so as to form an air gap bordered by the two first polymer blocks.

A semiconductor device comprising:

• a metal substrate that is formed with two metal lines that are spaced apart from each other;
• and
• a dielectric structure that is disposed between the two metal lines to electrically isolate the two metal lines;
• wherein the dielectric structure includes two polymer blocks that are respectively formed on sidewalls of the two metal lines bordering the dielectric structure, and an air gap that is sandwiched between the two polymer blocks.