Integrated circuit structures with different nanoribbon thicknesses

An integrated circuit (IC) structure, comprising:

• a first nanoribbon including a first channel region of a transistor, wherein the first channel region has a first length and a first thickness;
• and
• a second nanoribbon over the first nanoribbon, the second nanoribbon including a second channel region of the transistor, wherein the second channel region has a second length and a second thickness,
• wherein the first length is greater than the second length, and first thickness is greater than the second thickness.

A method of fabricating an integrated circuit (IC) structure, the method comprising:

• providing a stack of alternate layers of a semiconductor material and a further material, wherein the stack includes two or more layers of the semiconductor material with different thicknesses;
• patterning the stack into a fin;
• and
• removing portions of the further material to form nanoribbons from the two or more layers of the semiconductor material of the fin, wherein the nanoribbons include a first nanoribbon from a first layer of the semiconductor material and a second nanoribbon from a second layer of the semiconductor material, and wherein the first nanoribbon has a first thickness and the second nanoribbon has a second thickness that is different than the first thickness.