High electron mobility transistor

A high electron mobility transistor (HEMT), comprising:

• a first III-V compound layer;
• a second III-V compound layer disposed on the first III-V compound layer, wherein the second III-V compound layer is different from the first III-V compound layer in composition;
• a source electrode and a drain electrode disposed above the second III-V compound layer;
• a gate electrode disposed over the second III-V compound layer located between the source electrode and the drain electrode in a first direction, wherein the second III-V compound layer comprises a first region disposed under the gate electrode;
• a first moat at least partially disposed in the second III-V compound layer and at least partially disposed between the first region and the source electrode in the first direction;
• a second moat at least partially disposed in the second III-V compound layer and at least partially disposed between the first region and the drain electrode in the first direction, wherein the gate electrode is partially disposed in the first moat and the second moat, and the gate electrode overlaps a part of the second III-V compound layer disposed between the second moat and the drain electrode;
• and
• a gate dielectric layer disposed on the second III-V compound layer, wherein the second moat is filled with the gate dielectric layer and the gate electrode.

A high electron mobility transistor (HEMT), comprising:

• a first III-V compound layer;
• a second III-V compound layer disposed on the first III-V compound layer, wherein the second III-V compound layer is different from the first III-V compound layer in composition;
• a source electrode and a drain electrode disposed above the second III-V compound layer;
• a gate electrode disposed over the second III-V compound layer located between the source electrode and the drain electrode in a first direction, wherein the second III-V compound layer comprises a first region disposed under the gate electrode;
• a first moat at least partially disposed in the second III-V compound layer and at least partially disposed between the first region and the source electrode in the first direction;
• a second moat at least partially disposed in the second III-V compound layer and at least partially disposed between the first region and the drain electrode in the first direction;
• a third moat at least partially disposed in the second III-V compound layer and at least partially disposed between the first moat and the source electrode in the first direction;
• and
• a fourth moat at least partially disposed in the second III-V compound layer and at least partially disposed between the second moat and the drain electrode in the first direction.

A high electron mobility transistor (HEMT), comprising:

• a first III-V compound layer;
• a second III-V compound layer disposed on the first III-V compound layer, wherein the second III-V compound layer is different from the first III-V compound layer in composition;
• a source electrode and a drain electrode disposed above the second III-V compound layer;
• a gate electrode disposed over the second III-V compound layer located between the source electrode and the drain electrode in a first direction, wherein the second III-V compound layer comprises a first region disposed under the gate electrode;
• a first moat at least partially disposed in the second III-V compound layer and at least partially disposed between the first region and the source electrode in the first direction;
• a second moat at least partially disposed in the second III-V compound layer and at least partially disposed between the first region and the drain electrode in the first direction;
• and
• an auxiliary electrode disposed on a part of the second III-V compound layer disposed between the second moat and the drain electrode, wherein the auxiliary electrode is electrically connected with the source electrode.