The present disclosure, in some embodiments, relates to a method of forming a semiconductor structure. The method includes forming a plurality of bulk micro defects within a handle substrate. Sizes of the plurality of bulk micro defects are increased to form a plurality of bulk macro defects (BMDs) within the handle substrate. Some of the plurality of BMDs are removed from within a first denuded region and a second denuded region arranged along opposing surfaces of the handle substrate. An insulating layer is formed onto the handle substrate. A device layer comprising a semiconductor material is formed onto the insulating layer. The first denuded region and the second denuded region vertically surround a central region of the handle substrate that has a higher concentration of the plurality of BMDs than both the first denuded region and the second denuded region.

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.

Radio frequency (RF) circuits generate noise that can interfere with other RF circuits on the same semiconductor die. An isolation material disposed in an isolation region between a first active region of a first RF circuit and a second active region of a second RF circuit comprises a porosified region of the semiconductor material of the semiconductor die. The isolation material (e.g., porosified material) has a higher resistivity and lower permittivity than the semiconductor material to reduce transmission of noise interference between the first RF circuit and the second RF circuit. The isolation material in the isolation region of the semiconductor material comprises a porosity in the range 20% to 50% higher than the porosity of the semiconductor material in the first and second active regions. The porosified region has a lower permittivity and a higher resistivity than the non-porosified region to protect against the transmission of noise interference.

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.

A technique to make silicon oxide regions from porous silicon and related semiconductor structures is disclosed. The porous silicon is made in situ by anodizing P doped silicon regions. Thus, the shape and profile of the oxide regions may be controlled by controlling the shape and profile of the P doped silicon regions.

The present disclosure, in some embodiments, relates to a semiconductor structure. The semiconductor structure includes a handle substrate having a plurality of bulk macro defects (BMDs). An insulating layer is disposed onto a top surface of the handle substrate. A device layer, including a semiconductor material, is disposed onto the insulating layer. The handle substrate has a first denuded region and a second denuded region that vertically surround a central region of the handle substrate. The central region has a higher concentration of the plurality of BMDs than both the first denuded region and the second denuded region.

The present disclosure, in some embodiments, relates to a method of forming a semiconductor structure. The method includes forming a plurality of bulk micro defects within a handle substrate. Sizes of the plurality of bulk micro defects are increased to form a plurality of bulk macro defects (BMDs) within the handle substrate. Some of the plurality of BMDs are removed from within a first denuded region and a second denuded region arranged along opposing surfaces of the handle substrate. An insulating layer is formed onto the handle substrate. A device layer comprising a semiconductor material is formed onto the insulating layer. The first denuded region and the second denuded region vertically surround a central region of the handle substrate that has a higher concentration of the plurality of BMDs than both the first denuded region and the second denuded region.

A technique to make silicon oxide regions from porous silicon and related semiconductor structures is disclosed. The porous silicon is made in situ by anodizing P doped silicon regions. Thus, the shape and profile of the oxide regions may be controlled by controlling the shape and profile of the P doped silicon regions.

A technique to make silicon oxide regions from porous silicon and related semiconductor structures are disclosed. The porous silicon is made in situ by anodizing P doped silicon regions. Thus, the shape and profile of the oxide regions may be controlled by controlling the shape and profile of the P doped silicon regions.

A method of manufacturing a semiconductor device includes forming an auxiliary mask including a plurality of mask openings on a main surface of a crystalline semiconductor substrate. A porous structure is formed in the semiconductor substrate. The porous structure includes a porous layer at a distance to the main surface and porous columns that extend from the porous layer into direction of the main surface and that are laterally separated from each other by a non-porous portion. A non-porous device layer is formed on the non-porous portion and on the porous columns.