Method of manufacturing a semiconductor device

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

• forming a conductive structure including a conductive line and an insulation capping line covering an upper surface of the conductive line;
• forming an insulating spacer structure including a first insulating spacer, a second insulating spacer, and a third insulating spacer on a sidewall of the conductive structure, the second insulating spacer between the first insulating spacer and the third insulating spacer;
• forming a conductive layer on the conductive structure and the insulating spacer structure;
• forming a first landing pad recess region by a first etch process etching a portion of the conductive layer;
• forming a second landing pad recess region by a second etch process etching the insulating spacer structure, the second landing pad recess region exposing the second insulating spacer;
• and
• removing the second insulating spacer to form an air gap;
• wherein the second etch process has an etch rate of an insulating material higher than an etch rate of a conductive material.