Semiconductor device

A semiconductor device comprising

• a substrate,
• an electron transit layer disposed on the substrate,
• an electron supply layer disposed on the electron transit layer,
• a gate portion arranged on the electron supply layer, and
• a source electrode and a drain electrode that are disposed so as to sandwich the gate portion and are electrically connected to the electron supply layer, respectively, wherein
• the source electrode passes above the gate portion, extends toward the drain electrode side, and faces the drain electrode,
• the electron transit layer includes a conductive path forming layer in contact with the electron supply layer, a first semiconductor region containing an acceptor-type impurity, and a second semiconductor region disposed at a position closer to the conductive path forming layer than the first semiconductor region and containing an acceptor-type impurity,
• the first semiconductor region has a higher concentration of acceptor impurity than a concentration of acceptor impurity of the second semiconductor region,
• the gate portion includes a nitride semiconductor layer formed on the electron supply layer and a gate electrode formed on the nitride semiconductor layer, and
• the semiconductor device further comprises
• a passivation film covering a surface of the electron supply layer, a side surface of the nitride semiconductor layer, and a side surface and an upper surface of the gate electrode, and
• a barrier metal film disposed between the passivation film and the source electrode and formed so as to cover the gate portion, wherein
• both sides of the upper surface of a portion of the passivation film covering the gate portion are formed into curved surfaces of a convex shape protruding outward.