Semiconductor memory device

A method of manufacturing a semiconductor device, comprising:

• forming word lines extending in a first direction in a semiconductor substrate;
• forming bit line structures extending in a second direction intersecting the first direction;
• forming spacer structures extending along sidewalls of each of the bit line structures, each of the spacer structures comprising first and second spacers and a first sacrificial spacer between the first and second spacers;
• forming a second sacrificial spacer having a ring shape in a plan view, the second sacrificial spacer contacting a portion of the first sacrificial spacer between adjacent ones of the bit line structures;
• forming landing pads on the bit line structures defining a recess region exposing a portion of the second sacrificial spacer;
• and
• removing the first and second sacrificial spacers to form first and second air gaps.

A method of manufacturing a semiconductor device, comprising:

• forming word lines extending in a first direction in a semiconductor substrate;
• forming bit line structures crossing over the word lines and extending in a second direction intersecting the first direction;
• sequentially forming a first spacer, a first sacrificial spacer, and a second spacer on opposite sidewalls of each of the bit line structures;
• forming insulating patterns arranged along the second direction between the bit line structures to define a contact hole between adjacent ones of the insulating patterns and between the adjacent ones of the bit line structures;
• forming a preliminary contact pattern in the contact hole, the preliminary contact pattern exposing an upper sidewall of a hard mask pattern and upper sidewalls of the insulating patterns;
• after forming the preliminary contact pattern, forming a second sacrificial spacer connected to a portion of the first sacrificial spacer in the contact hole, the second sacrificial spacer covering the upper sidewall of the hard mask pattern and the upper sidewalls of the insulating patterns,
• forming a third spacer on the second sacrificial spacer;
• recessing a top surface of the preliminary contact pattern to form a contact pattern in the contact hole;
• forming a conductive layer filling the contact hole;
• forming mask patterns on the conductive layer
• etching the conductive layer using the mask patterns as an etch mask to form a landing pad on the contact pattern, a portion of the second sacrificial spacer exposed by the landing pad;
• and
• after forming the landing pad, removing the first and second sacrificial spacers to form first and second air gaps.