Nec Corporation

Samsung Electronics Co., Ltd.

Adeka Corporation

Shin-ichi Tanaka

Takashi Yamada

Kazuhiko Honjo

Jung-sik Choi

Myung-Beom Park

Ki-Hyeon Kim

Takehiro Zushi

Yuji Morishima

A copper electroplating method including dipping a substrate in a copper electroplating solution, the substrate including a seed layer; and forming a copper electroplating layer on the seed layer, wherein the copper electroplating solution includes water, a copper supply source, an electrolytic material, and a first additive, the first additive includes a compound represented by Formula 1, below: 

Copper electroplating method

The collector-top type transistor according to the present invention has at least principal semiconductor layers of an emitter layer, tunnel barrier layers having electron affinities smaller than those of the emitter and a base, the base layer, and a collector layer formed in the above-mentioned order on a semiconductor substrate in which the injection of the minority carriers from the emitter to the base is controlled by the tunneling mechanism via the tunnel barrier layer where the film thickness of the tunnel barrier layer in the extrinsic transistor region is regulated to be larger than that in the intrinsic transistor region.

Collector-top type transistor causing no deterioration in current gain

There is disclosed a heterojunction bipolar transistor comprising an emitter region having a first conductivity type, a base region having a second conductivity type opposite to the first conductivity type, and a collector region having a graded collector section formed of a first compound semiconductor material and a collector contact section formed of a second compound semiconductor material of the first conductivity type, and an emitter-base junction, a base-collector junction and an abrupt potential discontinuity are formed between the emitter region and the base region, between the base region and the graded collector section and between the graded collector section and the collector contact section, respectively, wherein the first compound semiconductor material is increased in bandgap from the base-collector junction toward the collector contact section and the second semiconductor material is smaller in bandgap at the abrupt junction than the first semiconductor material, so that the potential difference between the base region and the collector region is compensated by the abrupt potential discontinuity, thereby restricting the production of hot electrons.

Bipolar transistor with abrupt potential discontinuity in collector

For improvement in operation speed, there is provided a heterojunction bipolar transistor comprising, (a) an emitter region formed of a first semiconductor material of a first conductivity type, (b) a base region formed of a second semiconductor material of a second conductivity type opposite to the first conductivity type and forming a first junction together with the emitter region, and (c) a collector region formed of a third semiconductor material of the first conductivity type and forming a second junction together with the base region, the heterojunction bipolar transistor has a plurality of abrupt potential discontinuities including first and second abrupt potential discontinuities produced in succession to provide kinetic energies to a carrier injected from the emitter region, respectively, and the first abrupt potential discontinuity is produced at one of the first and second junctions, thereby allowing the carrier to move over a distance longer than a mean free path of the carrier in the ballistic manner.

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Tokyo, Japan

Shin-ichi Tanaka