Semiconductor device

A semiconductor device, comprising:

• a substrate;
• an active pattern on the substrate;
• a gate structure in an upper portion of the active pattern;
• a bit line structure on the active pattern, the bit line structure including a first metal;
• a first spacer on a sidewall of the bit line structure, the first spacer including an oxide of a second metal that has an ionization energy smaller than that of the first metal;
• a second spacer on an outer sidewall of the first spacer, the second spacer including an oxide of a third metal that is different from the second metal;
• a third spacer on a lower portion of an outer sidewall of the second spacer, the third spacer including a nitride;
• a fourth spacer on an upper portion of the outer sidewall of the second spacer and the third spacer;
• a fifth spacer and a sixth spacer sequentially stacked in a horizontal direction from an outer sidewall of the fourth spacer, the horizontal direction being substantially parallel to an upper surface of the substrate;
• a contact plug structure on the upper portion of the active pattern and adjacent to the bit line structure;
• and
• a capacitor on the contact plug structure.

A semiconductor device, comprising:

• a substrate;
• an active pattern on the substrate;
• a gate structure in an upper portion of the active pattern;
• a bit line structure on the active pattern, the bit line structure including a first conductive pattern, a second conductive pattern, and a capping pattern sequentially stacked in a vertical direction substantially perpendicular to an upper surface of the substrate;
• a first lower spacer at least partially covering a sidewall of the first conductive pattern, the first lower spacer including silicon oxide;
• a second lower spacer at least partially covering an outer sidewall of the first lower spacer, the second lower spacer including an oxide of a first metal;
• a third lower spacer on an outer sidewall of the second lower spacer, the third lower spacer including a second metal that is different from the first metal;
• a fourth lower spacer on the third lower spacer, the fourth lower spacer including a nitride;
• an upper spacer structure contacting upper surfaces of the first to third lower spacers and an upper sidewall of the bit line structure;
• a contact plug structure on the upper portion of the active pattern and adjacent to the bit line structure;
• and
• a capacitor on the contact plug structure.