Heterojunction field effect transistor

A heterojunction field effect transistor comprising:

• a GaN-based multilayer body having a heterojunction;
• a plurality of finger-shaped drain electrodes formed parallel to each other on the GaN-based multilayer body;
• a plurality of finger-shaped source electrodes formed parallel to each other on the GaN-based multilayer body such that the source electrodes and the drain electrodes are alternately arranged in an arrangement direction of the drain electrodes;
• gate electrodes formed in regions between the drain electrodes and the source electrodes in plan view;
• an interlayer insulating film formed on the GaN-based multilayer body so as to cover the source electrodes, the drain electrodes, and the gate electrodes;
• first contact portions formed in the interlayer insulating film in regions above at least portions of the respective source electrodes, the first contact portions extending in a longitudinal direction of the source electrodes;
• and
• second contact portions formed in the interlayer insulating film in regions above at least portions of the respective drain electrodes, the second contact portions extending in a longitudinal direction of the drain electrodes,
• wherein a length of the first contact portions in the longitudinal direction is smaller than a length of the source electrodes in the longitudinal direction,
• wherein a length of the second contact portions in the longitudinal direction is smaller than a length of the drain electrodes in the longitudinal direction, and
• wherein, in each drain electrode, a distance X from ends of the second contact portion to ends of the drain electrode, the ends being outside the second contact portion, is greater than a distance Y from ends of the first contact portion to ends of the source electrode, the ends being outside the first contact portion,
• wherein the length of the second contact portions in the longitudinal direction is smaller than the length of the first contact portions in the longitudinal direction,
• wherein the second contact portions are disposed between both ends of the first contact portions in the longitudinal direction of the first contact portions,
• wherein a length of the source electrodes in the longitudinal direction is smaller than a length of the drain electrodes in the longitudinal direction, and
• wherein the source electrodes are disposed between both ends of the drain electrodes in the longitudinal direction of the drain electrodes.