Patent ID: 7898057

Claim:
A radio frequency (RF) semiconductor device comprising: a die including an active area comprising an array of transistor cells, one or more of the transistor cells having a source region, a gate electrode and a drain region; the drain regions of one or more of the transistor cells being coupled together, a metal gate interconnection on an upper surface of the die and coupled to the gate electrodes of the cells, a metal source interconnection on the upper surface of the die and coupled to the source regions of the cells, and a metal drain interconnection on a bottom surface of the die and coupled to the drain regions of the cells; and a package to make electrical connections to the source regions, gate electrodes and drain regions of the cells, said package including an external source lead serving as a heat sink and coupled to the source interconnection, an external gate lead coupled to the gate interconnection, and an external drain lead coupled to the drain interconnection; wherein the die further comprises a dielectric platform surrounding the active area and wherein the gate interconnection is over the dielectric platform to at least partially shield the gate electrode from the drain region of the die, and further comprising a shielding plate being coupled to the external source lead of the package via the source region and being disposed between the gate interconnection and the drain region to at least partially decouple the capacitance between the gate electrode and the drain region; and wherein said dielectric platform comprises a matrix of silicon dioxide vertical structures and wherein the vertical structures are separated by cavities, top portions of the cavities are plugged and lower portions of the cavities are filled essentially with air.