Abstract: A first driver transistor includes a first gate insulating film that surrounds a periphery of a first island-shaped semiconductor, a first gate electrode having a first surface that is in contact with the first gate insulating film, and first and second first-conductivity-type high-concentration semiconductors disposed on the top and bottom of the first island-shaped semiconductor, respectively. A first load transistor includes a second gate insulating film having a first surface that is in contact with a second surface of the first gate electrode, a first arcuate semiconductor formed so as to be in contact with a portion of a second surface of the second gate insulating film, and first and second second-conductivity-type high-concentration semiconductors disposed on the top and bottom of the first arcuate semiconductor, respectively. A first gate line extends from the first gate electrode and is made of the same material as the first gate electrode.

Abstract: A semiconductor device with having a MOS varactor and methods of fabricating the same are disclosed. The MOS varactor includes a metal gate electrode, an active semiconductor plate interposed between the metal gate electrode and the semiconductor substrate, and a capacitor dielectric layer interposed between the metal gate electrode and the active semiconductor plate. Further, a lower insulating layer insulates the MOS varactor from the semiconductor substrate. According to the present invention, a metal gate electrode is used to reduce poly depletion, thereby increasing a tuning range of the varactor, and to manufacture a reliable metal resistor without the need of an additional photomask.