Semiconductor device and method for manufacturing the same

A semiconductor device comprising:

• a first GaN-based semiconductor layer;
• a second GaN-based semiconductor layer provided on the first GaN-based semiconductor layer, the second GaN-based semiconductor layer having a larger bandgap than the first GaN-based semiconductor layer;
• a source electrode provided on the second GaN-based semiconductor layer;
• a drain electrode provided on the second GaN-based semiconductor layer;
• a recess provided between the source electrode and the drain electrode in the second GaN-based semiconductor layer;
• a gate insulating film provided on a surface of the recess;
• and
• a gate electrode provided on the gate insulating film, located in the recess,
• wherein a length of the gate electrode in a gate width direction is larger than a length of the gate electrode in a gate length direction,
• a length of the recess in the gate width direction is larger than a length of the recess in the gate length direction, and
• the length of the recess in the gate width direction is larger than the length of the gate electrode in the gate width direction.

A semiconductor device comprising:

• a first GaN-based semiconductor layer;
• a second GaN-based semiconductor layer provided on the first GaN-based semiconductor layer, the second GaN-based semiconductor layer having a larger bandgap than the first GaN-based semiconductor layer;
• a source electrode provided on the second GaN-based semiconductor layer;
• a drain electrode provided on the second GaN-based semiconductor layer;
• a recess provided between the source electrode and the drain electrode in the second GaN-based semiconductor layer;
• a gate insulating film provided on a surface of the recess;
• and
• a gate electrode provided on the gate insulating film, located in the recess,
• wherein a length of the recess in a gate width direction is larger than a length of the gate electrode in the gate width direction, and
• the length of the recess in a gate length direction at an end portion of the recess in the gate width direction is longer than the length of the gate electrode in the gate length direction at an end portion of the gate electrode in the gate width direction.

A semiconductor device comprising:

• a first GaN-based semiconductor layer;
• a second GaN-based semiconductor layer provided on the first GaN-based semiconductor layer, the second GaN-based semiconductor layer having a larger bandgap than the first GaN-based semiconductor layer;
• a source electrode provided on the second GaN-based semiconductor layer;
• a drain electrode provided on the second GaN-based semiconductor layer;
• a recess provided between the source electrode and the drain electrode in the second GaN-based semiconductor layer;
• a gate insulating film provided on a surface of the recess;
• and
• a gate electrode provided on the gate insulating film, the gate electrode having an end portion in a gate width direction, located in the recess,
• wherein a first distance between the gate electrode and the bottom of the recess is shorter than a second distance between an end portion of the gate electrode in the gate width direction and a side surface of the recess, the gate length direction is parallel to a direction in which a current of the transistor flows, and the gate width direction is perpendicular to the gate length direction.

A semiconductor device comprising:

• a first GaN-based semiconductor layer;
• a second GaN-based semiconductor layer provided on the first GaN-based semiconductor layer, the second GaN-based semiconductor layer having a larger bandgap than the first GaN-based semiconductor layer;
• a source electrode provided on the second GaN-based semiconductor layer;
• a drain electrode provided on the second GaN-based semiconductor layer;
• a recess provided between the source electrode and the drain electrode in the second GaN-based semiconductor layer;
• a gate insulating film provided on a surface of the recess;
• and
• a gate electrode provided on the gate insulating film, located in the recess,
• wherein a length of the gate electrode in a gate width direction is larger than a length of the gate electrode in a gate length direction,
• a length of the recess in the gate width direction is larger than a length of the recess in the gate length direction,
• the length of the recess in the gate width direction is larger than the length of the gate electrode in the gate width direction,
• the gate length direction is parallel to a direction in which a current of the transistor flows, and the gate width direction is perpendicular to the gate length direction.