The present disclosure relates to a radio frequency device that includes a mold device die and a multilayer redistribution structure underneath the mold device die. The mold device die includes a device region with a back-end-of-line (BEOL) portion and a front-end-of-line (FEOL) portion over the BEOL portion, a barrier layer, and a first mold compound. The FEOL portion includes isolation sections and an active layer surrounded by the isolation sections. The barrier layer formed of silicon nitride resides over the active layer and top surfaces of the isolation sections. The first mold compound resides over the barrier layer. Herein, silicon crystal does not exist between the first mold compound and the active layer. The multilayer redistribution structure includes a number of bump structures, which are at a bottom of the multilayer redistribution structure and electrically coupled to the FEOL portion of the mold device die.