A semiconductor Schottky rectifier built in an epitaxial semiconductor layer over a substrate has an anode structure and a cathode structure extending from the surface of the epitaxial layer. The cathode contact structure has a trench structure near the epi-layer and a vertical sidewall surface covered with a gate oxide layer. The cathode structure further comprises a polysilicon element adjacent to the gate oxide layer.

A method includes forming a solder layer on a surface of one or more chips. A lid is positioned over the solder layer on each of the one or more chips. Heat and pressure are applied to melt the solder layer and attach each lid to a corresponding solder layer. The solder layer has a thermal conductivity of ≥50 W/mK.

A method includes forming a solder layer on a surface of one or more chips. A lid is positioned over the solder layer on each of the one or more chips. Heat and pressure are applied to melt the solder layer and attach each lid to a corresponding solder layer. The solder layer has a thermal conductivity of ≥50 W/mK.

A method for circuit fabrication includes defining a solder bump, including a specified solder material and having a specified bump volume, to be formed at a target location on an acceptor substrate. A transparent donor substrate, having a donor film including the specified solder material, is positioned such that the donor film is in proximity to the target location on the acceptor substrate. A sequence of pulses of laser radiation is directed to pass through the first surface of the donor substrate and impinge on the donor film so as to induce ejection from the donor film onto the target location on the acceptor substrate of a number of molten droplets of the solder material such that the droplets deposited at the target location cumulatively reach the specified bump volume. The target location is heated so the deposited droplets melt and reflow to form the solder bump.

A method of using a solder reflow oven can include disposing at least one substrate including solder in a chamber of the oven. The method can include decreasing a pressure of the chamber to a first pressure between about 0.1-50 Torr. After decreasing the pressure of the chamber, the temperature of the at least one substrate can be increased to a first temperature. Formic acid vapor can be admitted into the chamber above the at least one substrate while nitrogen is discharged into the chamber below the at least one substrate. The method can also include removing at least a portion of the formic acid vapor from the enclosure. After the removing step, the temperature of the at least one substrate can be further increased to a second temperature higher than the first temperature. The at least one substrate can be maintained at the second temperature for a first time. And then, the at least one substrate can be cooled.

A method of using a solder reflow oven can include disposing at least one substrate including solder in a chamber of the oven. The method can include decreasing a pressure of the chamber to a first pressure between about 0.1-50 Torr. After decreasing the pressure of the chamber, the temperature of the at least one substrate can be increased to a first temperature. Formic acid vapor can be admitted into the chamber above the at least one substrate while nitrogen is discharged into the chamber below the at least one substrate. The method can also include removing at least a portion of the formic acid vapor from the enclosure. After the removing step, the temperature of the at least one substrate can be further increased to a second temperature higher than the first temperature. The at least one substrate can be maintained at the second temperature for a first time. And then, the at least one substrate can be cooled.

A method includes bonding an antenna substrate to a redistribution structure. The antenna substrate has a first part of a first antenna, and the redistribution structure has a second part of the first antenna. The method further includes encapsulating the antenna substrate in an encapsulant, and bonding a package component to the redistribution structure. The redistribution structure includes a third part of a second antenna, and the package component includes a fourth part of the second antenna.

A method includes bonding an antenna substrate to a redistribution structure. The antenna substrate has a first part of a first antenna, and the redistribution structure has a second part of the first antenna. The method further includes encapsulating the antenna substrate in an encapsulant, and bonding a package component to the redistribution structure. The redistribution structure includes a third part of a second antenna, and the package component includes a fourth part of the second antenna.

A method for forming an underfill structure and semiconductor packages including the underfill structure are disclosed. In an embodiment, the semiconductor package may include a package including an integrated circuit die; an interposer bonded to the integrated circuit die by a plurality of die connectors; and an encapsulant surrounding the integrated circuit die. The semiconductor package may further include a package substrate bonded to the interposer by a plurality of conductive connectors; a first underfill between the package and the package substrate, the first underfill having a first coefficient of thermal expansion (CTE); and a second underfill surrounding the first underfill, the second underfill having a second CTE less than the first CTE.

A method for forming an underfill structure and semiconductor packages including the underfill structure are disclosed. In an embodiment, the semiconductor package may include a package including an integrated circuit die; an interposer bonded to the integrated circuit die by a plurality of die connectors; and an encapsulant surrounding the integrated circuit die. The semiconductor package may further include a package substrate bonded to the interposer by a plurality of conductive connectors; a first underfill between the package and the package substrate, the first underfill having a first coefficient of thermal expansion (CTE); and a second underfill surrounding the first underfill, the second underfill having a second CTE less than the first CTE.