The invention discloses a semiconductor device and a manufacturing method therefor. The semiconductor device comprises a semiconductor substrate, a grid stacked layer positioned above the semiconductor substrate, a grid electrode side wall positioned on the side face of the grid stacked layer, a source region and a drain region positioned in the semiconductor substrate, and a first conductive channel, a second conductive channel and a third conductive channel that are electrically connected with the source region, the drain region and the grid electrode conductor respectively, wherein the grid stacked layer comprises the grid electrode conductor and grid dielectric medium clamped between the grid electrode conductor and the semiconductor substrate; each conductive channel of the first conductive channel and the second conductive channel comprises a first part adjacent to the grid electrode side wall and a second part positioned above the grid electrode side wall; and the top of the first part is flush with the top of the gird electrode side wall, and the top of the first part is in contact with the bottom of the second part. According to the semiconductor device, the grid electrode conductor is separated from the first parts of the first conductive channel and the second conductive channel by the grid electrode side wall so as to reduce the occurrence of short circuit between the grid electrode, and the source and the drain; and in addition, the first parts and the second parts of the first conductive channel and the second conductive channel can adopt different conductive materials, so that the interconnection resistance can be reduced and/or the thermal conductance can be improved.