Semiconductor device and method for fabricating the same

A semiconductor device, comprising:

• a substrate including a first region and a second region different from each other;
• a first isolation insulating layer on the first region;
• a first active pattern on the first isolation insulating layer;
• a first gate electrode surrounding at least a portion of the first active pattern;
• a second isolation insulating layer on the second region;
• a second active pattern on the second isolation insulating layer;
• and
• a second gate electrode surrounding at least a portion of the second active pattern,
• wherein the first isolation insulating layer and the second isolation insulating layer include different materials.

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

• forming a laminate structure including sacrificial layers and active layers that are alternately stacked on a substrate, the substrate including a first region and a second region separated from each other;
• etching the laminate structure on the first region to form a first stacked structure protruding from a first sacrificial layer of the sacrificial layers;
• removing the first sacrificial layer and forming a first isolation insulating layer in a space from which the first sacrificial layer has been removed;
• etching the laminate structure on the second region to form a second stacked structure protruding from a second sacrificial layer of the sacrificial layers;
• removing the second sacrificial layer and forming a second isolation insulating layer in a space from which the second sacrificial layer has been removed;
• removing remaining ones of the sacrificial layers included in the first stacked structure and the second stacked structure;
• and
• forming a gate electrode in a space from which the remaining ones of the sacrificial layers have been removed to form a gate structure,
• wherein the first isolation insulating layer and the second isolation insulating layer are formed at different heights.