Abstract: A method of manufacturing a semiconductor device including implanting an element selected from fluorine and nitrogen, over the entire region of a semiconductor substrate; oxidizing the semiconductor substrate to thereby form a first oxide film over the surface of the semiconductor substrate; selectively removing the first oxide film in a partial region; oxidizing the semiconductor substrate in the partial region to thereby form a second oxide film thinner than the first oxide film in the partial region; and forming gates to thereby form transistors.

Abstract: A semiconductor device includes a MOSFET having: a gate electrode provided over a silicon substrate; and a first impurity diffusion region and a second impurity diffusion region provided in the silicon substrate in different sides of said first gate electrode, wherein the MOSFET has an extension region in an upper section of the first impurity diffusion region and no extension region in an upper section of the second impurity diffusion region, and has a first silicide layer over the first impurity diffusion region and has no silicide layer over the second impurity diffusion region in vicinity of a side edge of the gate electrode.

Abstract: The semiconductor device includes a plurality of transistors at least having different channel widths from each other. Threshold voltages of those transistors are set to be substantially equal to each other, by using both of substantially the same channel dose for each of those transistors, and work function control using a predetermined metal to be deposited on a gate insulating of those transistors and/or a gate electrode material of each of those transistors (that is, work function control based on a gate structure (gate insulating film and/or gate electrode) with respect to a channel region of each of those transistors).