Patent attributes
Semiconductor devices including a first transistor and a second transistor are integrated on a substrate. Each of the first and second transistors include a nano-sized active region including source and drain regions provided in respective end portions of the nano-sized active region and a channel forming region provided between the source and drain regions. The source and drain regions of the first transistor have the same conductivity type as those of the second transistor, and the second transistor has a threshold voltage lower than that of the first transistor. The channel forming region of the second transistor may include a homogeneously doped region, whose conductivity type is the same as the source and drain regions of the second transistor and is different from the channel forming region of the first transistor.