This invention provides a low-
voltage, high-
linearity heterojunction HEMT device based on junction field-effect modulation, comprising a substrate, a buffer layer, and a multilayer heterostructure of at least two alternating
layers of barrier and channel
layers. Source and drain electrodes are located on either side of the
barrier layer and extend into the buffer layer. A
passivation layer is formed on the upper surface of the
barrier layer. A gate trench is formed in the middle region of the
passivation layer, extending through the
passivation layer to the upper surface of the
barrier layer. The gate
electrode includes multiple discrete gate pillars and a gate cap. The multiple discrete gate pillars are periodically arranged along the gate width direction, located within the gate trench, and extend through at least two alternating
layers of barrier and channel layers into the buffer layer. The gate cap is located on the upper surface of the multiple discrete gate pillars, supported by the pillars, and has no contact with the passivation and barrier layers. A
metal interconnect layer is electrically connected to the source and drain electrodes. This design achieves both low
subthreshold swing and meets the application requirements of low
power consumption and high
linearity.