Semiconductor device

A semiconductor device comprising:

• a first semiconductor element;
• and
• a second semiconductor element,
• the first semiconductor element including:
• a first semiconductor layer made of an AlxGa1−xN (0≦x<1);
• a second semiconductor layer provided on the first semiconductor layer and made of an undoped or first conductivity type AlyGa1−yN (0<y≦1, x<y);
• an anode electrode and a cathode electrode which are connected to the second semiconductor layer;
• and
• a third semiconductor layer of second conductivity type provided between the anode electrode and the cathode electrode when viewed from a direction perpendicular to an upper surface of the second semiconductor layer,
• the second semiconductor element including:
• a fourth semiconductor layer made of an undoped AlzGa1−zN (0≦z<1);
• a fifth semiconductor layer provided on the fourth semiconductor layer and made of an undoped or first conductivity type AluGa1−uN (0<y≦1, z<u);
• and
• a source electrode and a drain electrode which are connected to the fifth semiconductor layer,
• the anode electrode being connected to the source electrode, and the cathode electrode being connected to the drain electrode, and
• the third semiconductor layer being depleted when a predetermined magnitude or more of voltage is applied between the anode electrode and the cathode electrode.

A semiconductor device comprising:

• a first semiconductor layer made of an AlxGa1−xN (0≦x<1);
• a second semiconductor layer provided on the first semiconductor layer and made of an undoped or first conductivity type AlyGa1−yN (0<y≦1, x<y);
• an anode electrode, a cathode electrode, and a source electrode which are connected to the second semiconductor layer;
• and
• a third semiconductor layer of second conductivity type provided between the anode electrode and the cathode electrode when viewed from a direction perpendicular to an upper surface of the second semiconductor layer,
• the third semiconductor layer being depleted when a predetermined magnitude or more of voltage is applied between the anode electrode and the cathode electrode.