Semiconductor device and method of fabricating the same

A semiconductor device comprising:

• a substrate;
• a device isolation layer on the substrate and defining an active pattern, a channel region of the active pattern vertically protruding beyond the device isolation layer;
• a gate electrode running across the channel region;
• and
• a high-k dielectric layer between the channel region and the gate electrode, wherein:
• the gate electrode includes:
• a work function metal pattern on the high-k dielectric layer;
• and
• an electrode pattern on the work function metal pattern,
• the high-k dielectric layer includes:
• a first part on a sidewall of the channel region;
• and
• a second part on a top surface of the channel region,
• the work function metal pattern and the high-k dielectric layer contain a same impurity, and
• an impurity concentration of the first part of the high-k dielectric layer is less than an impurity concentration of the work function metal pattern.

A semiconductor device comprising:

• a substrate;
• a first semiconductor pattern and a second semiconductor pattern vertically stacked on the substrate, the first and second semiconductor patterns being vertically spaced apart from each other;
• a gate electrode on the first and second semiconductor patterns;
• and
• a high-k dielectric layer between the gate electrode and the first and second semiconductor patterns, wherein:
• the gate electrode includes:
• a first work function metal pattern on the high-k dielectric layer;
• and
• an electrode pattern on the first work function metal pattern,
• the high-k dielectric layer and the gate electrode fill a first space between the first and second semiconductor patterns,
• the first work function metal pattern and the high-k dielectric layer contain a same impurity, and
• an impurity concentration of the high-k dielectric layer is less than an impurity concentration of the first work function metal pattern.