| abstract |
A transistor is provided. The transistor includes: a first source/drain epitaxial feature, a second source/drain epitaxial feature, and two or more semiconductor layers disposed on the first source/drain epitaxial feature and the second source between pole/drain epitaxial features. The two or more semiconductor layers are composed of different materials. The transistor also includes a gate electrode layer surrounding at least a portion of the two or more semiconductor layers, wherein the transistor has two or more threshold voltages. |