HEMT Source Field Plate Recess Electric Field Shielding

The device structure is segmented into multiple functional regions: a first dielectric layer with a first recess for electric field shielding, and a second dielectric layer with a second recess for charge trapping mitigation. This segmentation allows each layer to address specific reliability issues independently, improving overall device reliability without requiring complete structural redesign.

Dielectric layers are introduced as intermediary structures between the gate electrode and the semiconductor channel. These intermediary dielectric layers with recesses act as mediators that shield electric fields and prevent charge trapping, thereby improving reliability without directly modifying the active semiconductor regions.

The dielectric layers with recesses are formed preliminary to the gate electrode deposition. By pre-forming the recess structures in the dielectric layers before adding subsequent layers, the patent simplifies the overall manufacturing process compared to forming recesses after complete device assembly, as the recesses can be created using standard photolithography and etching processes on planar surfaces.

The dielectric layers are configured with local variations in thickness through the recess structures. The first dielectric layer has a first recess and the second dielectric layer has a second recess, creating localized regions with different electrical properties. This local quality approach allows targeted electric field shielding and charge trapping prevention only where needed, rather than requiring uniform thick dielectric layers throughout the entire device.