Patent ID: 11121057

Abstract:
The present disclosure relates to a radio frequency device that includes a device region with a back-end-of-line (BEOL) portion and a front-end-of-line (FEOL) portion, first bump structures, a first mold compound, and a second mold compound. The FEOL portion includes an active layer, a contact layer, and isolation sections. Herein, the active layer and the isolation sections reside over the contact layer, and the active layer is surrounded by the isolation sections. The BEOL portion is formed underneath the FEOL portion, and the first bump structures and the first mold compound are formed underneath the BEOL portion. Each first bump structure is partially encapsulated by the first mold compound, and electrically coupled to the FEOL portion via connecting layers within the BEOL portion. The second mold compound resides over the active layer without a silicon material, which has a resistivity between 5 Ohm-cm and 30000 Ohm-cm, in between.