Method of manufacturing a semiconductor device and a semiconductor device

A semiconductor device, comprising:

• a first plurality of nanowire structures extending in a first direction disposed over a first region of a semiconductor substrate,
• wherein each nanowire structure of the first plurality of nanowire structures includes a plurality of spaced-apart nanowires arranged in a second direction substantially perpendicular to the first direction;
• at least one second nanowire structure disposed over a second region of the semiconductor substrate,
• wherein each nanowire structure of the at least one second nanowire structure includes a plurality of nanowires arranged in the second direction;
• and
• a shallow trench isolation layer between the first region and the second region of the semiconductor substrate,
• wherein an uppermost surface of the shallow trench isolation layer is below a lowermost surface of a nanowire closest to the substrate of each of the first plurality of nanowire structures,
• wherein there is no shallow trench isolation layer between and below the nanowires closest to the substrate of the first plurality of nanowires.

A semiconductor device, comprising:

• an n-type transistor including a first nanowire structure extending in a first direction disposed over a mesa protruding from a surface of a semiconductor substrate,
• wherein the first nanowire structure includes a plurality of spaced-apart first nanowires arranged in a second direction perpendicular to the first direction;
• a p-type transistor including a second nanowire structure disposed over the mesa and spaced apart from the n-type transistor,
• wherein the second nanowire structure includes a plurality of second spaced-apart nanowires arranged in the second direction, and
• wherein there are no isolation structures in the mesa between the n-type transistor and the p-type transistor.