US Patent 10964812 Integration of input/output device in vertical field-effect transistor technology

A method for fabricating a semiconductor device includes forming a vertical field-effect transistor (FET) device including a plurality of first fin structures in a vertical FET device area of a substrate, and forming an input/output (IO) FET device including at least two second fin structures in an IO FET device area of the substrate. The at least two fin structures are connected by a channel having a length determined based on at least one voltage for implementing the IO FET device. Forming the vertical FET and IO FET devices includes selectively exposing a portion of the IO FET device area by selectively removing a portion of a first spacer formed on the substrate in the IO FET device area.