US Patent 9911817 Field-plate structures for semiconductor devices

Field-plate structures are disclosed for electrical field management in semiconductor devices. A field-plate semiconductor structure includes a semiconductor substrate, a source ohmic contact, a drain ohmic contact, and a gate contact disposed over a gate region between the source ohmic contact and the drain ohmic contact, and a source field plate connected to the source ohmic contact. A field-plate dielectric is disposed over the semiconductor substrate. An encapsulating dielectric is disposed over the gate contact, wherein the encapsulating dielectric covers a top surface of the gate contact. The source field plate is disposed over the field-plate dielectric in a field plate region, from which the encapsulating dielectric is absent.