Semiconductor structure

A semiconductor structure comprising:

• a first fin structure and a second fin structure;
• a first semiconductor oxide layer disposed over the first fin structure, wherein the first semiconductor oxide layer comprises a first semiconductor material;
• a second semiconductor oxide layer disposed over the second fin structure, wherein the second semiconductor oxide layer comprises a first semiconductor material and a second semiconductor material;
• and
• a first gate electrode disposed over the first dielectric layer, and a second gate electrode disposed over the second dielectric layer;
• wherein the second fin structure includes the first semiconductor material and the second semiconductor material, and a concentration of the second semiconductor material is outwardly reduced, and
• wherein a thickness of the first semiconductor oxide layer and a thickness of the second semiconductor oxide layer are equal.

A semiconductor structure comprising:

• a silicon (Si) fin structure and a silicon germanium (SiGe) fin structure;
• a high-k dielectric layer over the Si fin structure and the SiGe fin structure;
• a first dielectric layer between the high-k dielectric layer and Si fin structure, and a second dielectric layer between the high-k dielectric layer and the SiGe fin structure;
• and
• a first metal gate electrode over the high-k dielectric layer and a second metal gate electrode over the high-k dielectric layer,
• wherein the first dielectric layer comprises silicon oxide, the second dielectric layer comprises silicon germanium oxide, and a thickness of the first dielectric layer and a thickness of the second dielectric layer are equal.