Semiconductor device including mos transistor

A semiconductor device, comprising:

• a first MOS transistor on a semiconductor substrate and including a first gate including a first gate dielectric structure and a first gate electrode structure;
• a second MOS transistor on the semiconductor substrate and including a second gate dielectric structure and a second gate electrode structure;
• a third MOS transistor on the semiconductor substrate and including a third gate including a third gate dielectric structure and a third gate electrode structure;
• and
• a fourth MOS transistor on the semiconductor substrate and including a fourth gate including a fourth gate dielectric structure and a fourth gate electrode substrate,
• wherein each of the first to fourth gate dielectric structures includes a common dielectric substrate, the first gate dielectric substrate includes a first upper dielectric on the common dielectric structure, the fourth gate dielectric structure includes a second upper dielectric on the common dielectric structure, and the second gate dielectric structure and the third gate dielectric structure include a mixture of the first upper dielectric and the second upper dielectric.

A semiconductor device, comprising:

• a first transistor, the first transistor being of a first conductivity type, the first transistor including a semiconductor layer between source/drain regions, and a gate electrode structure surrounding the semiconductor layer and spaced apart therefrom by a first gate dielectric structure;
• and
• a second transistor, the second transistor being of the first conductivity type and having a different threshold voltage from the first transistor, the second transistor including a semiconductor layer between source/drain regions, and a gate electrode structure surrounding the semiconductor layer and spaced apart therefrom by a second gate dielectric structure, wherein:
• the first gate dielectric structure and the second gate dielectric structure each include a same high-k dielectric material,
• the first gate dielectric structure includes a first dielectric material on the high-k dielectric material, and
• the second gate dielectric structure includes a second dielectric material on the high-k dielectric material, the second dielectric material forming a dipole.