Resistive element and power amplifier circuit

A resistive element, comprising:

• a resistive element portion;
• and
• a conduction control layer, wherein
• the resistive element portion includes:
• a substrate;
• a first nitride semiconductor layer above the substrate;
• a second nitride semiconductor layer above the first nitride semiconductor layer, the second nitride semiconductor layer having a band gap larger than a band gap of the first nitride semiconductor layer;
• a two-dimensional electron gas layer on a first nitride semiconductor layer side at an interface between the first nitride semiconductor layer and the second nitride semiconductor layer;
• a first electrode disposed above the first nitride semiconductor layer and ohmically connected to the two-dimensional electron gas layer;
• a second electrode disposed above the first nitride semiconductor layer and apart from the first electrode in plan view, and ohmically connected to the two-dimensional electron gas layer;
• and
• an insulating layer between the first electrode and the second electrode in the plan view, the insulating layer being in contact with a top surface of the second nitride semiconductor layer, wherein
• the two-dimensional electron gas layer between the first electrode and the second electrode in the plan view functions as an electric resistance element,
• the conduction control layer
• is disposed above the insulating layer between the first electrode and the second electrode in the plan view,
• has a length, in a direction in which the first electrode and the second electrode are aligned in the plan view, which is at least half a space between the first electrode and the second electrode, and
• supplies an electric field to the two-dimensional electron gas layer to control a resistance value of the electric resistance element, in accordance with a voltage supplied from a source outside of the resistive element portion, and
• the resistive element has a resistance-value stabilization structure that functions to keep a resistance value of the electric resistance element constant.