Compound semiconductor device and method of manufacturing the same

A power supply apparatus, comprising

• a compound semiconductor device, wherein the compound semiconductor device comprises:
• a carrier transit layer;
• a carrier supply layer over the carrier transit layer;
• a source electrode and a drain electrode above the carrier supply layer;
• a gate electrode above the carrier supply layer between the source electrode and the drain electrode;
• and
• a first insulating film, a second insulating film, and a third insulating film above the carrier supply layer between the gate electrode and the drain electrode, wherein
• the gate electrode includes a portion above the third insulating film,
• a first concentration of electron traps in the first insulating film is higher than a second concentration of electron traps in the second insulating film, and
• a third concentration of electron traps in the third insulating film is higher than the second concentration of the electron traps in the second insulating film.

An amplifier, comprising

• a compound semiconductor device, wherein the compound semiconductor device comprises:
• a carrier transit layer;
• a carrier supply layer over the carrier transit layer;
• a source electrode and a drain electrode above the carrier supply layer;
• a gate electrode above the carrier supply layer between the source electrode and the drain electrode;
• and
• a first insulating film, a second insulating film, and a third insulating film above the carrier supply layer between the gate electrode and the drain electrode, wherein
• the gate electrode includes a portion above the third insulating film,
• a first concentration of electron traps in the first insulating film is higher than a second concentration of electron traps in the second insulating film, and
• a third concentration of electron traps in the third insulating film is higher than the second concentration of the electron traps in the second insulating film.

A method of manufacturing a compound semiconductor device comprising:

• forming a carrier supply layer over a carrier transit layer;
• forming a source electrode and a drain electrode above the carrier supply layer;
• forming a gate electrode above the carrier supply layer between the source electrode and the drain electrode;
• and
• forming a first insulating film, a second insulating film, and a third insulating film above the carrier supply layer between the gate electrode and the drain electrode, wherein
• the gate electrode includes a portion above the third insulating film,
• a first concentration of electron traps in the first insulating film is higher than a second concentration of electron traps in the second insulating film, and
• a third concentration of electron traps in the third insulating film is higher than the second concentration of the electron traps in the second insulating film.