A III-N enhancement-mode transistor includes a III-N structure including a conductive channel, source and drain contacts, and a gate electrode between the source and drain contacts. An insulator layer is over the III-N structure, with a recess formed through the insulator layer in a gate region of the transistor, with the gate electrode at least partially in the recess. The transistor further includes a field plate having a portion between the gate electrode and the drain contact, the field plate being electrically connected to the source contact. The gate electrode includes an extending portion that is outside the recess and extends towards the drain contact. The separation between the conductive channel and the extending portion of the gate electrode is greater than the separation between the conductive channel and the portion of the field plate that is between the gate electrode and the drain contact.