Abstract: A semiconductor device including a well region formed in a silicon substrate; a trench exposing a predetermined portion of the uppermost surface of the semiconductor substrate; a body layer formed in the semiconductor substrate at the trench; a device isolation layer formed in the well region; a gate insulating layer formed in the trench over the body layer; a gate electrode formed in the trench over the gate insulating layer and against the device isolation layer; a lightly doped drain region formed in the body layer; an insulating layer formed in the trench over the lightly doped drain region; a source region formed in the body layer; a drain region formed in the well region against the device isolation layer; and a body region formed in the body layer against the source region. The on-resistance can be reduced by forming the gate and source beneath the device isolating layer.

Abstract: An optical element including a transmitting surface section and at least one reflective surface section integrally formed on a main body of the optical element. The transmitting surface section refracts incident light emitted from a predetermined light-emitting position and transmits the light. The reflective surface section reflects the incident light emitted from the light-emitting position such that the light returns to a position differing from the light-emitting position. An optical axis of the transmitting surface section and an optical axis of the reflective surface section are out of alignment such as to be mutually parallel or mutually tilted.