Patent ID: 11296046

Abstract:
The present disclosure relates to a radio frequency (RF) 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, and a first mold compound. The FEOL portion includes an active layer formed from a strained silicon epitaxial layer, in which a lattice constant is greater than 5.461 at a temperature of 300K. The first mold compound resides over the active 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.