Methods and devices used to cancel non-linear capacitances in high power radio frequency (RF) switches manufactured in bulk complementary metal-oxide-semiconductor (CMOS) processes are disclosed. The methods and devices are also applicable to stacked switches and RF switches fabricated in silicon-on-insulator (SOI) technology.

A radiofrequency filter includes a substrate, an isolation structure, an electrically conductive structure, a spacer structure, a dielectric layer, a patterned electrically conductive film, a first contact structure, and a second contact structure. The isolation structure is disposed in the substrate. The electrically conductive structure is disposed on the isolation structure. The spacer structure is disposed on the substrate and located on a sidewall of the electrically conductive structure. The dielectric layer is disposed on the electrically conductive structure. The patterned electrically conductive film is disposed on the dielectric layer. At least a part of the dielectric layer is located between the electrically conductive structure and the patterned electrically conductive film in a vertical direction. The first contact structure and the second contact structure are disposed on and electrically connected with the patterned electrically conductive film.

A radiofrequency filter includes a substrate, an isolation structure, an electrically conductive structure, a spacer structure, a dielectric layer, a patterned electrically conductive film, a first contact structure, and a second contact structure. The isolation structure is disposed in the substrate. The electrically conductive structure is disposed on the isolation structure. The spacer structure is disposed on the substrate and located on a sidewall of the electrically conductive structure. The dielectric layer is disposed on the electrically conductive structure. The patterned electrically conductive film is disposed on the dielectric layer. At least a part of the dielectric layer is located between the electrically conductive structure and the patterned electrically conductive film in a vertical direction. The first contact structure and the second contact structure are disposed on and electrically connected with the patterned electrically conductive film.

A dual sided molded package has a substrate with pads of varying size configured to receive electrically conductive interconnect members thereon. The pads include first pads that have a larger surface area than a surface area of second pads. In one implementation, one or more first pads are proximate the corners of the substrate. First interconnect members are attached to the first pads and second interconnect members are attached to the second pads. The first interconnect members have an exposed solderable area that is substantially equal to the surface area of the first pads, and the second interconnect members have an exposed solderable area that is substantially equal to the surface area of the second pads. The first exposed solderable area is larger than the second exposed solderable area.

In an embodiment, a method includes: forming an integrated circuit die, forming the integrated circuit die comprising: forming an interconnect structure over a front side of a substrate, the interconnect structure comprising a photonic component and a heater, the substrate comprising a first dielectric layer over a semiconductor substrate; removing the semiconductor substrate to expose a back side of the first dielectric layer; forming a second dielectric layer over the back side of the first dielectric layer; forming a redistribution structure over the second dielectric layer, the redistribution structure extending through the first dielectric layer and the second dielectric layer to be electrically connected to the interconnect structure; and forming an electrical connector over the redistribution structure; attaching a package substrate to the electrical connector; and attaching an electronic die over the interconnect structure and over the front side of the package substrate.