Semiconductor device and method of fabricating the same

A semiconductor device comprising:

• a substrate;
• a first active pattern on the substrate;
• a gate electrode surrounding the first active pattern;
• an inner spacer on a sidewall of the gate electrode, wherein the inner spacer is between the first active pattern and the substrate;
• and
• an epitaxial pattern contacting the first active pattern and the inner spacer,
• wherein the inner spacer comprises a semiconductor material.

A semiconductor device comprising:

• a substrate comprising a first region and a second region;
• a first gate electrode on the first region, the first gate electrode extending in a first direction;
• a first gate spacer on a sidewall of the first gate electrode, the first gate spacer comprising a first semiconductor material;
• a first active pattern penetrating the first gate electrode and the first gate spacer, the first active pattern extending in a second direction crossing the first direction;
• a first epitaxial pattern on a sidewall of the first gate spacer;
• a second gate electrode on the second region, the second gate electrode extending in a third direction;
• a second active pattern penetrating the second gate electrode, the second active pattern extending in a fourth direction crossing the third direction;
• and
• a second epitaxial pattern on a sidewall of the second gate electrode.