Abstract
A nitride-based semiconductor device includes first and second nitride-based semiconductor layers, first electrodes, doped nitride-based semiconductor layers, a second electrode, and gate electrodes. The second nitride-based semiconductor layer is disposed on the first nitride-based semiconductor layer. The first and second nitride-based semiconductor layers collectively have an active portion and an electrically isolating portion surrounding the active portion. The first electrodes are disposed over the second nitride-based semiconductor layer. The first electrodes, doped nitride-based semiconductor layers, the gate electrode, and the second electrode are disposed over the second nitride-based semiconductor layer. Each of the doped nitride-based semiconductor layers has a side surface facing away from the second electrode and spaced apart from the interface.