Patent ID: 7838907

Claim:
A semiconductor device comprising: a high electron mobility transistor and a diode in a same semiconductor chip, wherein the semiconductor chip has a semiconductor substrate having a first main surface and a second main surface positioned on mutually opposite sides in a thickness direction and a compound semiconductor layer formed on the semiconductor substrate, wherein the high electron mobility transistor has the compound semiconductor layer, a drain electrode, a gate electrode and a source electrode formed on a main surface of the compound semiconductor layer, wherein the diode has a cathode region formed in the semiconductor substrate, an anode region formed on the first main surface side of the semiconductor substrate so as to be in contact with the cathode region and an anode electrode formed on the main surface of the compound semiconductor layer, wherein the anode electrode is electrically connected to the anode region via a conductive material embedded in a hole which reaches the anode region of the first main surface of the semiconductor substrate from the main surface of the compound semiconductor layer, wherein the source electrode of the high electron mobility transistor and the anode region of the diode are electrically connected to each other, wherein a cathode electrode of the diode is electrically connected to the drain electrode of the high electron mobility transistor in the semiconductor chip, wherein the semiconductor substrate has a first semiconductor layer and a second semiconductor layer of a first conductivity type sequentially stacked from the second main surface, wherein the first semiconductor layer has a first impurity concentration, wherein the second semiconductor layer has a second impurity concentration lower than the first impurity concentration, and wherein the cathode electrode of the diode is electrically connected to the drain electrode via the conductive material embedded in a hole which reaches the first semiconductor layer of the semiconductor substrate from the main surface of the compound semiconductor layer.