US Patent 11605638 Transistors with multiple threshold voltages

Semiconductor structures and methods are provided. A method according to the present disclosure includes forming a first channel member, a second channel member directly over the first channel member, and a third channel member directly over the second channel member, depositing a first metal layer around each of the first channel member, the second channel member, and the third channel member, removing the first metal layer from around the second channel member and the third channel member while the first channel member remains wrapped around by the first metal layer, after the removing of the first metal layer, depositing a second metal layer around the second channel member and the third channel member, removing the second metal layer from around the third channel member, and after the removing of the second metal layer, depositing a third metal layer around the third channel member.