Semiconductor device having nanosheets

A semiconductor device comprising:

• a first transistor over a substrate, wherein the first transistor comprises a first plurality of nanosheets, the first transistor has a first sheet width, and the first transistor has a first power efficiency;
• a second transistor over the substrate, wherein the second transistor comprises a second plurality of nanosheets, the second transistor has the first sheet width, and the second transistor has a second power efficiency different from the first power efficiency;
• and
• an isolation structure between the first transistor and the second transistor.

A semiconductor device comprising:

• a first transistor over a substrate, wherein the first transistor comprises a first plurality of nanosheets, and the first plurality of nanosheets has a first height;
• a second transistor over the substrate, wherein the second transistor comprises a second plurality of nanosheets, the second plurality of nanosheets has a second height, and the second height is different from the first height;
• and
• an isolation structure between the first transistor and the second transistor.