Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device, comprising:

• forming a first nitride-based semiconductor layer over a substrate;
• forming a second nitride-based semiconductor layer on the first nitride-based semiconductor layer;
• forming a gate electrode over the second nitride-based semiconductor layer;
• forming a first dielectric layer on the second nitride-based semiconductor layer and the gate electrode;
• forming a first field plate over the first dielectric layer;
• forming a second dielectric layer on the first dielectric layer and the first field plate;
• forming a second field plate over the second dielectric layer;
• and
• forming a first electrode and a second electrode over the second nitride-based semiconductor layer, wherein the gate electrode is located between the first and second electrodes,
• wherein the first field plate comprises:
• a first portion located in a region between the first electrode and the gate electrode and not vertically overlapping with the gate electrode;
• a second portion partially and vertically overlapping with the gate electrode;
• and a third portion connecting the first portion to the second portion,
• wherein the second field plate comprises:
• a fourth portion located in a region between the first electrode and the first field plate and not vertically overlapping with the first field plate;
• a fifth portion partially and vertically overlapping with the first portion of the first field plate;
• and a sixth portion connecting the fourth portion and the fifth portion, and
• wherein the second field plate does not vertically overlap with the gate electrode, and a height of a top-most surface of the second field plate with respect to the second nitride-based semiconductor layer is less than a height of a top-most surface of the first field plate with respect to the second nitride-based semiconductor layer.

A semiconductor device, comprising:

• a first nitride-based semiconductor layer disposed above a substrate;
• a second nitride-based semiconductor layer disposed on the first nitride-based semiconductor layer and having a bandgap greater than a bandgap of the first nitride-based semiconductor layer;
• a first electrode and a second electrode disposed above the second nitride-based semiconductor layer;
• a first gate electrode disposed above the second nitride-based semiconductor layer and between the first and second electrodes;
• a first field plate disposed over the second nitride-based semiconductor layer and extending from a region between the first electrode and the first gate electrode to a region directly over the first gate electrode;
• a second field plate disposed over the second nitride-based semiconductor layer and extending from a region between the first electrode and the first field plate to a region directly over the first field plate, wherein the second field plate is horizontally spaced away from the first gate electrode;
• a third electrode disposed above the second nitride-based semiconductor layer, wherein the second electrode is located between the first and third electrodes;
• a second gate electrode disposed above the second nitride-based semiconductor layer and located between the second and third electrodes;
• a third field plate disposed over the second nitride-based semiconductor layer and extending from a region between the third electrode and the second gate electrode to a region directly over the second gate electrode;
• and
• a fourth field plate disposed over the second nitride-based semiconductor layer and extending from a region between the third electrode and the third field plate to a region directly over the third field plate.