Solder bumps are placed in direct contact with the silicon substrate of an amplifier integrated circuit having a flip chip configuration. A plurality of amplifier transistor arrays generate waste heat that promotes thermal run away of the amplifier if not directed out of the integrated circuit. The waste heat flows through the thermally conductive silicon substrate and out the solder bump to a heat-sinking plane of an interposer connected to the amplifier integrated circuit via the solder bumps.

Aspects of the disclosure provide a bipolar transistor structure with an elevated extrinsic base, and related methods to form the same. A bipolar transistor according to the disclosure may include a collector on a substrate, and a base film on the collector. The base film includes a crystalline region on the collector and a non-crystalline region adjacent the crystalline region. An emitter is on a first portion of the crystalline region of the base film. An elevated extrinsic base is on a second portion of the crystalline region of the base film, and adjacent the emitter.

A semiconductor device includes a bipolar junction transistor (BJT) structure including emitters in a first well having a first conductive type, collectors in respective second wells, the second wells having a second conductive type different from the first conductive type and being spaced apart from each other with the first well therebetween, and bases in the first well and between the emitters and the collectors. The BJT structure includes active regions having different widths that form the emitters, the collectors, and the bases.

Aspects of the disclosure provide a bipolar transistor structure with an elevated extrinsic base, and related methods to form the same. A bipolar transistor according to the disclosure may include a collector on a substrate, and a base film on the collector. The base film includes a crystalline region on the collector and a non-crystalline region adjacent the crystalline region. An emitter is on a first portion of the crystalline region of the base film. An elevated extrinsic base is on a second portion of the crystalline region of the base film, and adjacent the emitter.

A semiconductor device is provided that has a semiconductor substrate, a drift layer of a first conductivity type formed in the semiconductor substrate, a base region of a second conductivity type formed in the semiconductor substrate and above the drift layer, and an accumulation region of the first conductivity type provided between the drift layer and the base region and having an impurity concentration higher than an impurity concentration in the drift layer, wherein the accumulation region has a first accumulation region and a second accumulation region that is formed more shallowly than the first accumulation region is and on a side of a boundary with a region that is different from the accumulation region in a planar view.

A structure includes an electrical device, and an active contact landed on a portion of the electrical device. The active contact includes a first body of a first material. A thermal dissipation pillar is adjacent the active contact and unlanded on but over the portion of the electrical device. The thermal dissipation pillar includes a second body of a second material having a higher thermal conductivity than the first material. The thermal dissipation pillar may be in thermal communication with a wire in a dielectric layer over the active contact and the thermal dissipation pillar. The electrical device can be any integrated circuit device that generates heat.

Aspects of the disclosure provide an integrated circuit (IC) structure with a bipolar transistor stack within a substrate. The bipolar transistor stack may include: a collector, a base on the collector, and an emitter on a first portion of the base. A horizontal width of the emitter is less than a horizontal width of the base, and an upper surface of the emitter is substantially coplanar with an upper surface of the substrate. An extrinsic base structure is on a second portion of the base of the bipolar transistor stack, and horizontally adjacent the emitter. The extrinsic base structure includes an upper surface above the upper surface of the substrate.

A vertical bipolar transistor device is disclosed. The vertical bipolar transistor device includes a heavily-doped semiconductor substrate, a first semiconductor epitaxial layer, at least one first doped well, and an external conductor. The heavily-doped semiconductor substrate and the first doped well have a first conductivity type. The first semiconductor epitaxial layer has a second conductivity type. The first semiconductor epitaxial layer is formed on the heavily-doped semiconductor substrate. The first doped well is formed in the first semiconductor epitaxial layer. The external conductor is arranged outside the heavily-doped semiconductor substrate and the first semiconductor epitaxial layer and electrically connected to the heavily-doped semiconductor substrate and the first semiconductor epitaxial layer.

A device includes a substrate, a drift region in the substrate, a base region above the drift region; a first high concentration region selectively formed in a part on a surface side of the base region and having a concentration higher than the drift region; a trench portion formed in a front surface of the substrate and including extending portions; and mesa portions between the extending portions. The mesa portions includes first mesa portions having the first high concentration region and second mesa portions not having the first high concentration region, the trench portion includes a first trench portion having an first conductive portion (a gate conductive potion) and adjacent to the first mesa portion, a second trench portion having the first conductive portion and adjacent to the second mesa portion, and a third trench portion having an second conductive portion and adjacent to the first or second mesa portion.

A cascode transistor device includes a semiconductor substrate, and a first and a second compound semiconductor transistors. The first compound semiconductor transistor includes a first n-type doping layer, a first p-type doping layer and a second n-type doping layer sequentially disposed on the semiconductor substrate. The second compound semiconductor transistor includes a third n-type doping layer, a second p-type doping layer and a fourth n-type doping layer sequentially disposed on the second n-type doping layer. Each of these doping layers is formed with an exposed metal contact. The exposed metal contact on the second n-type doping layer is electrically connected to the exposed metal contact on the third n-type doping layer.