Semiconductor device

A semiconductor device comprising:

• a group-III nitride semiconductor layered structure that includes a heterojunction;
• an insulating layer which has a gate opening that reaches the group-III nitride semiconductor layered structure and which is disposed on the group-III nitride semiconductor layered structure;
• a gate insulating film that covers a bottom and a side of the gate opening;
• a gate electrode defined on the gate insulating film inside the gate opening;
• a source electrode and a drain electrode which are disposed to be spaced apart from the gate electrode such that the source electrode and the drain electrode sandwich the gate electrode and each of which are electrically connected to the group-III nitride semiconductor layered structure;
• a first conductive layer embedded in the insulating layer between the gate electrode and the drain electrode and electrically connected to the source electrode;
• a second conductive layer that is embedded in the insulating layer above the first conductive layer in a region closer to the drain electrode side than the first conductive layer and electrically connected to the source electrode;
• and
• a third conductive layer which is disposed above the insulating layer in a region closer to the drain electrode side than the second conductive layer and electrically connected to the source electrode.

A semiconductor device comprising:

• a group-III nitride semiconductor layered structure that includes a heterojunction;
• an insulating layer which has a gate opening that reaches the group-III nitride semiconductor layered structure and which is disposed on the group-III nitride semiconductor layered structure;
• a gate insulating film that covers a bottom and a side of the gate opening;
• a gate electrode defined on the gate insulating film inside the gate opening;
• a source electrode and a drain electrode which are disposed to be spaced apart from the gate electrode such that the source electrode and the drain electrode sandwich the gate electrode and each of which are electrically connected to the group-III nitride semiconductor layered structure;
• a first conductive layer embedded in the insulating layer between the gate electrode and the drain electrode and electrically connected to the source electrode;
• a second conductive layer that is embedded in the insulating layer above the first conductive layer in a region closer to the drain electrode side than the first conductive layer and electrically connected to the source electrode;
• and
• a third conductive layer which is embedded in the insulating layer above the second conductive layer in a region closer to the drain electrode side than the second conductive layer and electrically connected to the source electrode.

A semiconductor device comprising:

• a group-III nitride semiconductor layered structure that includes a heterojunction;
• an insulating layer which has a gate opening that reaches the group-III nitride semiconductor layered structure and which is disposed on the group-III nitride semiconductor layered structure;
• a gate insulating film that covers a bottom and a side of the gate opening;
• a gate electrode defined on the gate insulating film inside the gate opening;
• a source electrode and a drain electrode which are disposed to be spaced apart from the gate electrode such that the source electrode and the drain electrode sandwich the gate electrode and each of which are electrically connected to the group-III nitride semiconductor layered structure;
• a first conductive layer embedded in the insulating layer between the gate electrode and the drain electrode and electrically connected to the source electrode;
• and
• a second conductive layer that is embedded in the insulating layer above the first conductive layer in a region closer to the drain electrode side than the first conductive layer and electrically connected to the source electrode, wherein
• the insulating layer includes a first insulating layer supporting the first conductive layer, a second insulating layer covering the first conductive layer and supporting the second conductive layer, and a third insulating layer covering the second conductive layer;
• and
• the first insulating layer is formed of a SiN layer.

A semiconductor device comprising:

• a group-III nitride semiconductor layered structure that includes a heterojunction;
• an insulating layer which has a gate opening that reaches the group-III nitride semiconductor layered structure and which is disposed on the group-III nitride semiconductor layered structure;
• a gate insulating film that covers a bottom and a side of the gate opening;
• a gate electrode defined on the gate insulating film inside the gate opening;
• a source electrode and a drain electrode which are disposed to be spaced apart from the gate electrode such that the source electrode and the drain electrode sandwich the gate electrode and each of which are electrically connected to the group-III nitride semiconductor layered structure;
• a first conductive layer embedded in the insulating layer between the gate electrode and the drain electrode and electrically connected to the source electrode;
• a second conductive layer that is embedded in the insulating layer above the first conductive layer in a region closer to the drain electrode side than the first conductive layer and electrically connected to the source electrode;
• and
• a floating conductive layer which is embedded in the insulating layer between the gate electrode and the source electrode, the floating conductive layer being insulated from the gate electrode by the gate insulating film and also insulated from the source electrode.