A bipolar transistor including a first collector layer, a second collector layer, a base layer, and an emitter layer is disposed on a substrate. Etching characteristics of the second collector layer are different from etching characteristics of the first collector layer and the base layer. In plan view, an edge of an interface between the first collector layer and the second collector layer is disposed inside an edge of a lower surface of the base layer, and an edge of an upper surface of the second collector layer coincides with the edge of the lower surface of the base layer or is disposed inside the edge of the lower surface of the base layer.

A method of manufacturing an electronic device includes providing a substrate, forming a solder on the substrate, and bonding a diode to the substrate through the solder, wherein the solder is formed by stacking a plurality of first conductive layers and a plurality of second conductive layers alternately, and the plurality of first conductive layers and the plurality of second conductive layers include different materials.

A method of manufacturing an electronic device includes providing a substrate, forming a solder on the substrate, and bonding a diode to the substrate through the solder, wherein the solder is formed by stacking a plurality of first conductive layers and a plurality of second conductive layers alternately, and the plurality of first conductive layers and the plurality of second conductive layers include different materials.

A bonded assembly includes a first semiconductor die that includes first metallic bonding structures embedded within a first bonding-level dielectric layer, and a second semiconductor die that includes second metallic bonding structures embedded within a second bonding-level dielectric layer and bonded to the first metallic bonding structures by metal-to-metal bonding. One of the first metallic bonding structures a pad portion, and a via portion located between the pad portion and the first semiconductor device, the via portion having second tapered sidewalls.

A light emitting device including a first LED stack, a second LED stack disposed on the first LED stack, a third LED stack disposed on the second LED stack, and a common electrode electrically connected to a first conductivity type semiconductor layer of each of the first, second, and third LED stacks, in which the common electrode includes a step in at least one of the first, second and third LED stacks.

A circuit element is formed on a substrate made of a compound semiconductor. A bonding pad is disposed on the circuit element so as to at least partially overlap the circuit element. The bonding pad includes a first metal film and a second metal film formed on the first metal film. A metal material of the second metal film has a higher Young's modulus than a metal material of the first metal film.

A circuit element is formed on a substrate made of a compound semiconductor. A bonding pad is disposed on the circuit element so as to at least partially overlap the circuit element. The bonding pad includes a first metal film and a second metal film formed on the first metal film. A metal material of the second metal film has a higher Young's modulus than a metal material of the first metal film.

A light source unit for a display device includes: a printed circuit board including a soldering pad located on a substrate of glass and including a copper layer, and a first diffusing barrier pattern located on the soldering pad and including a molybdenum alloy; and a light emitting diode mounted on the soldering pad through a solder resist. In one embodiment, the printed circuit board is a glass printed circuit board.

A display apparatus is disclosed that includes a substrate, a display element, a transistor, and a pad. The substrate includes a display area and a peripheral area. The display element is disposed on the display area. The transistor is electrically connected to the display element. The pad is disposed on the peripheral area and having a multilayered structure. The pad includes a pad metal layer, a first pad protective layer disposed on the pad metal layer, and a second pad protective layer interposed between the pad metal layer and the first pad protective layer. The second pad protective layer includes a different material from the first pad protective layer. The transistor includes a semiconductor layer disposed on the substrate, a gate electrode disposed on a gate insulating layer that covers the semiconductor layer, and a connection electrode arranged on an interlayer insulating layer covering the gate electrode. The connection electrode has the same multilayered structure as the multilayered structure of the pad, and the connection electrode is connected to the semiconductor layer.

An interfacial structure, along with methods of forming such, are described. The structure includes a first interfacial layer having a first dielectric layer, a first conductive feature disposed in the first dielectric layer, and a first thermal conductive layer disposed on the first dielectric layer. The structure further includes a second interfacial layer disposed on the first interfacial layer. The second interfacial layer is a mirror image of the first interfacial layer with respect to an interface between the first interfacial layer and the second interfacial layer. The second interfacial layer includes a second thermal conductive layer disposed on the first thermal conductive layer, a second dielectric layer disposed on the second thermal conductive layer, and a second conductive feature disposed in the second dielectric layer.