Abstract: The present disclosure describes a front-end module (FEM) and a process for making the same. In the disclosed FEM, a thinned flip-chip die, which includes a device region with a metal layer, resides over a module carrier. A mold compound resides over the module carrier, surrounds the thinned flip-chip die, and extends beyond a top surface of the thinned flip-chip die to define an opening over the top surface of the thinned flip-chip die and within the mold compound. A ferrimagnetic portion resides over the top surface of the thinned flip-chip die and within the opening, and a permanent magnetic portion resides over the ferrimagnetic portion and within the opening. Herein, the permanent magnetic portion, the ferrimagnetic portion, and the metal layer of the device region are vertically aligned, and form a circulator vertically stacked with the thinned flip-chip die.

Abstract: A method for a base station in communication with a user device through a wireless communications network is described. The method includes communicating with a user device on a current frequency through a wireless communications network. The method may also include determining, based at least in part on a model, a probability that a higher capacity may be acquired by the user device on a frequency other than the current frequency; predicting a first recommended frequency for the user device that is likely to have a higher capacity than the current frequency; instructing the user device to scan the first recommended frequency; receiving an indication from the user device that the first recommended frequency has a higher capacity than the current frequency; and communicating with the user device on the first recommended frequency.

Abstract: The present disclosure relates to a switch system that provides a control method for switches based on dual-phase materials. The disclosed switch system includes a heat resistor, a power management (PM) unit configured to provide a control voltage at a voltage port coupled to the heat resistor, and a phase-change-based switch. Herein, the heat resistor is underneath the phase-change-based switch, and configured to generate heat energy from the control voltage and provide the heat energy to the phase-change-based switch. The phase-change-based switch is capable of being switched on and off by switching between a crystalline phase and an amorphous phase based on the heat energy provided by the heat resistor. The control voltage provided by the PM unit contains waveform information of target heat energy required for switching on and off the phase-change-based switch.

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, 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 first mold compound resides over the active layer without silicon crystal, which has no germanium content, in between. The multilayer redistribution structure includes redistribution interconnections and a number of bump structures that are at bottom of the multilayer redistribution structure and electrically coupled to the mold device die via the redistribution interconnections.

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, 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 first mold compound resides over the active layer without silicon crystal, which has no germanium content, in between. The multilayer redistribution structure includes redistribution interconnections and a number of bump structures that are at bottom of the multilayer redistribution structure and electrically coupled to the mold device die via the redistribution interconnections.

Abstract: The present disclosure relates to a radio frequency device that includes a transfer device die and a multilayer redistribution structure underneath the transfer device die. The transfer 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 transfer substrate. The FEOL portion includes isolation sections and an active layer surrounded by the isolation sections. A top surface of the device region is planarized. The transfer substrate resides over the top surface of the device region. Herein, silicon crystal does not exist within the transfer substrate or between the transfer substrate 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 transfer device die.

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.

Abstract: The present disclosure relates to a radio frequency (RF) device including a device substrate, a thinned device die with a device region over the device substrate, a first mold compound, and a second mold compound. The device region includes an isolation portion, a back-end-of-line (BEOL) portion, and a front-end-of-line (FEOL) portion with a contact layer and an active section. The contact layer resides over the BEOL portion, the active section resides over the contact layer, and the isolation portion resides over the contact layer to encapsulate the active section. The first mold compound resides over the device substrate, surrounds the thinned device die, and extends vertically beyond the thinned device die to define an opening over the thinned device die and within the first mold compound. The second mold compound fills the opening and directly connects the isolation portion of the thinned device die.

Abstract: The present disclosure relates to a radio frequency device that includes a transfer device die and a multilayer redistribution structure underneath the transfer device die. The transfer 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 transfer substrate. The FEOL portion includes isolation sections and an active layer surrounded by the isolation sections. A top surface of the device region is planarized. The transfer substrate including a porous silicon (PSi) region resides over the top surface of the device region. Herein, the PSi region has a porosity between 1% and 80%. 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 transfer device die.

Abstract: The present disclosure relates to a thermally enhanced package, which includes a carrier, a thinned die over the carrier, a mold compound, and a heat extractor. The thinned die includes a device layer over the carrier and a dielectric layer over the device layer. The mold compound resides over the carrier, surrounds the thinned die, and extends beyond a top surface of the thinned die to define an opening within the mold compound and over the thinned die. The top surface of the thinned die is at a bottom of the opening. At least a portion of the heat extractor is inserted into the opening and in thermal contact with the thinned die. Herein the heat extractor is formed of a metal or an alloy.

Abstract: The present disclosure relates to a radio frequency (RF) device including a device substrate, a thinned device die with a device region over the device substrate, a first mold compound, and a second mold compound. The device region includes an isolation portion, a back-end-of-line (BEOL) portion, and a front-end-of-line (FEOL) portion with a contact layer and an active section. The contact layer resides over the BEOL portion, the active section resides over the contact layer, and the isolation portion resides over the contact layer to encapsulate the active section. The first mold compound resides over the device substrate, surrounds the thinned device die, and extends vertically beyond the thinned device die to define an opening over the thinned device die and within the first mold compound. The second mold compound fills the opening and directly connects the isolation portion of the thinned device die.

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, a thermally conductive film, and a first mold compound. The FEOL portion includes isolation sections and an active layer surrounded by the isolation sections. The thermally conductive film, which has a thermal conductivity greater than 10 W/m·K and an electrical resistivity greater than 1E5 Ohm-cm, resides between the active layer and the first mold compound. 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.

Abstract: The present disclosure relates to a Gallium-Nitride (GaN) based module, which includes a module substrate, a thinned switch die residing over the module substrate, a first mold compound, and a second mold compound. The thinned switch die includes an electrode region, a number of switch interconnects extending from a bottom surface of the electrode region to the module substrate, an aluminium gallium nitride (AlGaN) barrier layer over a top surface of the electrode region, a GaN buffer layer over the AlGaN barrier layer, and a lateral two-dimensional electron gas (2DEG) layer realized at a heterojunction of the AlGaN barrier layer and the GaN buffer layer. The first mold compound resides over the module substrate, surrounds the thinned switch die, and extends above a top surface of the thinned switch die to form an opening over the top surface of the thinned switch die. The second mold compound fills the opening.

Abstract: The present disclosure relates to a thermally enhanced package, which includes a carrier, a thinned die over the carrier, a mold compound, and a heat extractor. The thinned die includes a device layer over the carrier and a dielectric layer over the device layer. The mold compound resides over the carrier, surrounds the thinned die, and extends beyond a top surface of the thinned die to define an opening within the mold compound and over the thinned die. The top surface of the thinned die is at a bottom of the opening. At least a portion of the heat extractor is inserted into the opening and in thermal contact with the thinned die. Herein the heat extractor is formed of a metal or an alloy.

Abstract: The present disclosure relates to a radio frequency (RF) device and a process for making the same. According to the process, a precursor wafer, which includes device regions, individual interfacial layers, individual p-type doped layers, and a silicon handle substrate, is firstly provided. Each individual interfacial layer is over an active layer of a corresponding device region, each individual p-type doped layer is over a corresponding individual interfacial layer, and the silicon handle substrate is over each individual p-type doped layer. Herein, each individual interfacial layer is formed of SiGe, and each individual p-type doped layer is a silicon layer doped with a p-type material that has a doped concentration greater than 1E18cm-3. Next, the silicon handle substrate is completely removed to provide an etched wafer, and each individual p-type doped layer is completely removed from the etched wafer.

Abstract: The present disclosure relates to a radio frequency (RF) device including a device substrate, a thinned device die with a device region over the device substrate, a first mold compound, and a second mold compound. The device region includes an isolation portion, a back-end-of-line (BEOL) portion, and a front-end-of-line (FEOL) portion with a contact layer and an active section. The contact layer resides over the BEOL portion, the active section resides over the contact layer, and the isolation portion resides over the contact layer to encapsulate the active section. The first mold compound resides over the device substrate, surrounds the thinned device die, and extends vertically beyond the thinned device die to define an opening over the thinned device die and within the first mold compound. The second mold compound fills the opening and directly connects the isolation portion of the thinned device die.

Abstract: The present disclosure relates to a Gallium-Nitride (GaN) based module, which includes a module substrate, a thinned switch die residing over the module substrate, a first mold compound, and a second mold compound. The thinned switch die includes an electrode region, a number of switch interconnects extending from a bottom surface of the electrode region to the module substrate, an aluminium gallium nitride (AlGaN) barrier layer over a top surface of the electrode region, a GaN buffer layer over the AlGaN barrier layer, and a lateral two-dimensional electron gas (2DEG) layer realized at a heterojunction of the AlGaN barrier layer and the GaN buffer layer. The first mold compound resides over the module substrate, surrounds the thinned switch die, and extends above a top surface of the thinned switch die to form an opening over the top surface of the thinned switch die. The second mold compound fills the opening.

Abstract: The present disclosure relates to a radio frequency (RF) device and a process for making the same. According to the process, a precursor wafer, which includes device regions, individual interfacial layers, individual p-type doped layers, and a silicon handle substrate, is firstly provided. Each individual interfacial layer is over an active layer of a corresponding device region, each individual p-type doped layer is over a corresponding individual interfacial layer, and the silicon handle substrate is over each individual p-type doped layer. Herein, each individual interfacial layer is formed of SiGe, and each individual p-type doped layer is a silicon layer doped with a p-type material that has a doped concentration greater than 1E18cm-3. Next, the silicon handle substrate is completely removed to provide an etched wafer, and each individual p-type doped layer is completely removed from the etched wafer.

Abstract: The present disclosure relates to a thermally enhanced package, which includes a carrier, a thinned die over the carrier, a mold compound, and a heat extractor. The thinned die includes a device layer over the carrier and a dielectric layer over the device layer. The mold compound resides over the carrier, surrounds the thinned die, and extends beyond a top surface of the thinned die to define an opening within the mold compound and over the thinned die. The top surface of the thinned die is at a bottom of the opening. At least a portion of the heat extractor is inserted into the opening and in thermal contact with the thinned die. Herein the heat extractor is formed of a metal or an alloy.

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, a thermally conductive film, and a first mold compound. The FEOL portion includes isolation sections and an active layer surrounded by the isolation sections. The thermally conductive film, which has a thermal conductivity greater than 10 W/m·K and an electrical resistivity greater than 1E5 Ohm-cm, resides between the active layer and the first mold compound. 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.