Integrated circuit device having a bit line and a main insulating spacer with an extended portion

An integrated circuit device comprising:

• a bit line comprising a lower conductive layer and an upper conductive layer on the lower conductive layer in a vertical direction, the lower conductive layer being on a substrate and the upper conductive layer having a width less than a width of the lower conductive layer in a horizontal direction;
• an insulating capping pattern on the upper conductive layer in the vertical direction, the insulating capping pattern having a width greater than the width of the upper conductive layer in the horizontal direction;
• and
• a main insulating spacer on a sidewall of the bit line and a sidewall of the insulating capping pattern, the main insulating spacer comprising an extended portion that is convex toward the upper conductive layer,
• wherein the width of the upper conductive layer in the horizontal direction varies along the vertical direction.

An integrated circuit device comprising:

• a substrate comprising a plurality of active regions apart from each other, the plurality of active regions comprising a first active region and a second active region adjacent to the first active region;
• a bit line connected to the first active region and comprising a lower conductive layer and an upper conductive layer stacked on the substrate in a vertical direction;
• an insulating capping pattern on the bit line;
• a contact plug adjacent to the bit line in a horizontal direction, the contact plug being connected to the second active region;
• and
• a spacer structure between the bit line and the contact plug,
• wherein the spacer structure comprises a main insulating spacer comprising an extended portion opposite the upper conductive layer, the extended portion protruding toward the upper conductive layer compared to a portion of the main insulating spacer opposite the lower conductive layer,
• wherein the extended portion of the main insulating spacer fills an undercut space corresponding to a sidewall of the upper conductive layer and a bottom surface of the insulating capping pattern, and
• wherein the extended portion of the main insulating spacer and the portion of the main insulating spacer opposite the lower conductive portion form a continuous portion of a common material.