During electro-oxidative metal removal on a semiconductor substrate, the substrate having a metal layer is anodically biased and the metal is electrochemically dissolved into an electrolyte. Metal particles (e.g., copper particles when the dissolved metal is copper) can inadvertently form on the surface of the substrate during electrochemical metal removal and cause defects during subsequent semiconductor processing. Contamination with such particles can be mitigated by preventing particle formation and/or by dissolution of particles. In one implementation, mitigation involves using an electrolyte that includes an oxidizer, such as hydrogen peroxide, during the electrochemical metal removal. An electrochemical metal removal apparatus in one embodiment has a conduit for introducing an oxidizer to the electrolyte and a sensor for monitoring the concentration of the oxidizer in the electrolyte.

A semiconductor package including a first stack; a plurality of TSVs passing through the first stack; a second stack on the first stack and including a second surface facing a first surface of the first stack; a first pad on the first stack and in contact with the TSVs; a second pad on the second stack; a bump connecting the first and second pads; a first redundancy pad on the first surface of the first stack, spaced apart from the first pad, and not in contact with the TSVs; a second redundancy pad on the second surface of the second stack and spaced apart from the second pad; and a redundancy bump connecting the first redundancy pad and the second redundancy pad, wherein the first pad and first redundancy pad are electrically connected to each other, and the second pad and second redundancy pad are electrically connected to each other.

A chip structure including a chip body and a plurality of conductive bumps. The chip body includes an active surface and a plurality of bump pads disposed on the active surface. The conductive bumps are disposed on the active surface of the chip body and connected to the bump pads respectively, and at least one of the conductive bumps has a trapezoid shape having one pair of parallel sides and one pair of non-parallel sides.

An electronic device includes a multilevel package substrate with first and second levels extending in planes of first and second directions and spaced apart from one another along a third direction, the first level having a first side with landing areas spaced apart from one another along the first direction. The multilevel package substrate includes a conductive structure having first and second ends and conductive portions in the first and second levels that provide a conductive path along the first direction from the landing areas toward the second end, where the conductive structure includes indents that extend into the conductive portions in the first level, the indents spaced apart from one another along the first direction and positioned along the first direction between respective pairs of the landing areas.

A semiconductor package including a first stack; a plurality of TSVs passing through the first stack; a second stack on the first stack and including a second surface facing a first surface of the first stack; a first pad on the first stack and in contact with the TSVs; a second pad on the second stack; a bump connecting the first and second pads; a first redundancy pad on the first surface of the first stack, spaced apart from the first pad, and not in contact with the TSVs; a second redundancy pad on the second surface of the second stack and spaced apart from the second pad; and a redundancy bump connecting the first redundancy pad and the second redundancy pad, wherein the first pad and first redundancy pad are electrically connected to each other, and the second pad and second redundancy pad are electrically connected to each other.

A radio frequency (“RF”) transistor amplifier die includes a semiconductor layer structure having a plurality of transistor cells, and an insulating layer on a surface of the semiconductor layer structure. Conductive pillar structures protrude from the insulating layer opposite the surface of the semiconductor layer structure, and are configured to provide input signal, output signal, or ground connections to the transistor cells. The ground connections are arranged between the input and/or output signal connections to the transistor cells. Related devices and packages are also discussed.

A method of using a processing oven may include disposing at least one substrate in a chamber of the oven and activating a lamp assembly disposed above them to increase their temperature to a first temperature. A chemical vapor may be admitted into the chamber above the at least one substrate and an inert gas may be admitted into the chamber below the at least one substrate. The temperature of the at least one substrate may then be increased to a second temperature higher than the first temperature and then cooled down.

A method of using a processing oven may include disposing at least one substrate in a chamber of the oven and activating a lamp assembly disposed above them to increase their temperature to a first temperature. A chemical vapor may be admitted into the chamber above the at least one substrate and an inert gas may be admitted into the chamber below the at least one substrate. The temperature of the at least one substrate may then be increased to a second temperature higher than the first temperature and then cooled down.

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.