Abstract: A semiconductor device includes a supporting substrate; a semiconductor film on the supporting substrate; a gate insulating film on the semiconductor film; a gate electrode on the gate insulating film; and a source region and a drain region formed by introducing impurity elements to the semiconductor film. The thickness of the semiconductor film is within the range of 20 nm to 40 nm. Low-concentration regions are provided between the source region and a channel forming region, and between the drain region and the channel forming region, respectively. The low-concentration regions each have an impurity concentration smaller than that of the source region and that of the drain region, and the impurity concentration in a lower surface side region on the side of the supporting substrate is smaller than that of an upper surface side region on the opposite side.

Abstract: A semiconductor device includes a supporting substrate; a semiconductor film on the supporting substrate; a gate insulating film on the semiconductor film; a gate electrode on the gate insulating film; and a source region and a drain region formed by introducing impurity elements to the semiconductor film. The thickness of the semiconductor film is within the range of 20 nm to 40 nm. Low-concentration regions are provided between the source region and a channel forming region, and between the drain region and the channel forming region, respectively. The low-concentration regions each have an impurity concentration smaller than that of the source region and that of the drain region, and the impurity concentration in a lower surface side region on the side of the supporting substrate is smaller than that of an upper surface side region on the opposite side.