Patent ID: 11923313
Assignee: QORVO US, INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 9:
10. An apparatus comprising:
a mold device die comprising a device region, a first mold compound, and an extra layer, wherein:
the device region includes a front-end-of-line (FEOL) portion and a back-end-of-line (BEOL) portion, which resides underneath the FEOL portion and comprises connecting layers;
the FEOL portion comprises an active layer, a contact layer, and isolation sections, wherein a bottom surface of the active layer and bottom surfaces of the isolation sections are in contact with a top surface of the contact layer, the isolation sections surround the active layer, the isolation sections do not reside over the active layer, and the isolation sections extend vertically beyond a top surface of the active layer to define an opening within the isolation sections and over the active layer;
the extra layer is in contact with the top surface of the active layer of the FEOL portion and within the opening, wherein the extra layer is formed of silicon germanium or silicon nitride; and
the first mold compound directly resides over the extra layer to fill the opening, wherein no silicon crystal exists between the first mold compound and the active layer;

a multilayer redistribution structure formed underneath the BEOL portion of the mold device die, wherein the multilayer redistribution structure comprises a plurality of bump structures on a bottom surface of the multilayer redistribution structure and redistribution interconnections within the multilayer redistribution structure, wherein the plurality of bump structures are electrically coupled to the FEOL portion of the mold device die via the redistribution interconnections and the connecting layers within the BEOL portion; and
a second mold compound residing over the multilayer redistribution structure and encapsulating the mold device die.