SEMICONDUCTOR DEVICE AND METHOD OF FABRICATING THE SAME

Disclosed are semiconductor devices and their fabricating methods. The semiconductor device comprises first and second active patterns, a first channel pattern including first semiconductor patterns, a second channel pattern including second semiconductor patterns, a gate electrode on the first and second channel patterns, and a gate dielectric layer between the gate electrode and the first and second channel patterns. The gate electrode includes a first inner gate electrode between the first semiconductor patterns, a second inner gate electrode between the second semiconductor patterns, and an outer gate electrode outside the first and second semiconductor patterns. The first and second inner gate electrodes are on bottom surfaces of uppermost first and second semiconductor patterns. The outer gate electrode is on top surfaces and sidewalls of the uppermost first and second semiconductor patterns. The first and second inner gate electrodes have different work functions.