US 12,262,556 B2
Power amplifier
Shaojun Ma, Nagaokakyo (JP); Shigeki Koya, Nagaokakyo (JP); Masayuki Aoike, Nagaokakyo (JP); Shinnosuke Takahashi, Nagaokakyo (JP); Yasunari Umemoto, Nagaokakyo (JP); and Masatoshi Hase, Nagaokakyo (JP)
Assigned to Murata Manufacturing Co., Ltd., Kyoto-fu (JP)
Filed by Murata Manufacturing Co., Ltd., Kyoto-fu (JP)
Filed on Dec. 13, 2021, as Appl. No. 17/549,566.
Claims priority of application No. 2020-207804 (JP), filed on Dec. 15, 2020.
Prior Publication US 2022/0190124 A1, Jun. 16, 2022
Int. Cl. H01L 29/737 (2006.01); H01L 29/423 (2006.01); H03F 3/217 (2006.01); H10D 10/80 (2025.01); H10D 64/00 (2025.01); H10D 64/23 (2025.01); H10D 64/27 (2025.01); H10D 64/60 (2025.01)
CPC H10D 64/118 (2025.01) [H03F 3/217 (2013.01); H10D 10/821 (2025.01); H10D 64/231 (2025.01); H10D 64/281 (2025.01); H10D 64/60 (2025.01)] 9 Claims
OG exemplary drawing
 
1. A power amplifier that includes a substrate, and an emitter layer, a base layer, and a collector layer laminated in this order on a major surface of the substrate, the power amplifier comprising:
an electrical insulator adjacent to the emitter layer;
an emitter electrode between the substrate and both the emitter layer and the electrical insulator;
a base electrode electrically connected to the base layer;
a collector electrode electrically connected to the collector layer; and
an etching stop layer separating the base layer from the collector layer in a direction perpendicular to the major surface of the substrate, wherein
the base electrode overlaps the emitter electrode, the electrical insulator, the base layer, and the substrate in the direction perpendicular to the major surface of the substrate,
the base electrode is electrically connected to the base layer by passing through the etching stop layer separating the base layer from the collector layer,
the base electrode further comprises two main portions extending in a first direction parallel to the major surface of the substrate and a connection portion connecting the two main portions by extending in a second direction parallel to the major surface of the substrate and perpendicular to the first direction, and
the base electrode comprising the two main portions and the connection portion being surrounded by the etching stop layer and separated from the collector layer by the etching stop layer.