Semiconductor device and method of fabricating the same

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

• forming an active pattern;
• forming a gate structure extending lengthwise in a first direction on the active pattern;
• forming a storage node contact on the active pattern;
• forming a preliminary pad layer on the storage node contact;
• and
• etching the preliminary pad layer to form a landing pad,
• wherein the landing pad comprises:
• a first pad flat sidewall parallel to the first direction;
• a second pad flat sidewall parallel to the first direction and opposite to the first pad flat sidewall;
• a third pad flat sidewall between the first pad flat sidewall and the second pad flat sidewall;
• a fourth pad flat sidewall between the first pad flat sidewall and the second pad flat sidewall;
• a first pad curved sidewall between the first pad flat sidewall and the third pad flat sidewall;
• a second pad curved sidewall between the first pad flat sidewall and the fourth pad flat sidewall;
• a third pad curved sidewall between the second pad flat sidewall and the third pad flat sidewall;
• and
• a fourth pad curved sidewall between the second pad flat sidewall and the fourth pad flat sidewall,
• wherein a distance between the first pad curved sidewall and the fourth pad curved sidewall is greater than a distance between the second pad curved sidewall and the third pad curved sidewall.

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

• forming an active pattern;
• forming a gate structure on the active pattern;
• forming a bit-line structure on the active pattern;
• forming a storage node contact on the active pattern;
• forming a preliminary pad layer on the storage node contact;
• forming a base pattern on the preliminary pad layer;
• and
• etching the preliminary pad layer using the base pattern as an etching mask to form a landing pad,
• wherein forming the base pattern comprises:
• forming a mask structure on the preliminary pad layer;
• forming a first mask line extending lengthwise in a first direction on the mask structure;
• etching the mask structure using the first mask line as an etching mask to form a second mask line;
• forming a third mask line extending lengthwise in a second direction intersecting the first direction on the second mask line;
• and
• etching the second mask line using the third mask line as an etching mask.