AlGaN/GaN Heterojunction Bipolar Transistors With Record fᴛ/fₘₐₓ=21.6 /4.23 GHz

We report a novel GaN heterojunction bipolar transistor (HBT) featuring n-AlGaN/n<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup>-GaN emitter layers, achieving a record <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub>/f<sub>MAX</sub></i> = 21.6/4.23 GHz at the current density of 12.7 mA and V<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CE</sub>=10V. This is the first time that the frequency of GaN HBTs have been extended to the S-band. The exceptional performance is attributed to three advancements in material and device fabrication: （1）regrowth emitter technology is used to achieve base ohmic contact, thereby reducing the parasitic base resistance. (2) An n<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup>-GaN emitter cap layer is used to achieve an ultra-low specific contact resistance of 1.35 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup>Ω·cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, effectively lowering the total emitter resistance, thereby reducing the collector charging time τ<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</i>. (3) down-scaling technologies, which reduce the parasitic base resistance and the base-collector (BC) junction capacitance, also helps to increasing the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i>. The device demonstrates a power density of 1.31 MW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, which is the highest for GaN HBTs on sapphire. These results underscore the potential of GaN HBTs for high-power, high-efficiency RF applications.

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Publication Details

Journal
IEEE Electron Device Letters
Published
2025-04-08
DOI
https://doi.org/10.1109/led.2025.3558540
Citations
2
Primary Topic
GaN-based semiconductor devices and materials
Type
article
Field-Weighted Citation Impact
2.52
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article

AlGaN/GaN Heterojunction Bipolar Transistors With Record fᴛ/fₘₐₓ=21.6 /4.23 GHz

Wei Tan, Jiaheng He, Weibin Wang, Jianxing Xu et al.
2 citations
IEEE Electron Device Letters
GaN-based semiconductor devices and materials
2.52
article

AlGaN/GaN Heterojunction Bipolar Transistors With Record fᴛ/fₘₐₓ=21.6 /4.23 GHz

Wei Tan, Jiaheng He, Weibin Wang, Jianxing Xu, Zhe Cheng, Yun Zhang, Xiaodong Wang, Lian Zhang, Changxin Mi, Chunyan Liu
article en
2 citations

Abstract

We report a novel GaN heterojunction bipolar transistor (HBT) featuring n-AlGaN/n<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup>-GaN emitter layers, achieving a record <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub>/f<sub>MAX</sub></i> = 21.6/4.23 GHz at the current density of 12.7 mA and V<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CE</sub>=10V. This is the first time that the frequency of GaN HBTs have been extended to the S-band. The exceptional performance is attributed to three advancements in material and device fabrication: （1）regrowth emitter technology is used to achieve base ohmic contact, thereby reducing the parasitic base resistance. (2) An n<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup>-GaN emitter cap layer is used to achieve an ultra-low specific contact resistance of 1.35 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup>Ω·cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, effectively lowering the total emitter resistance, thereby reducing the collector charging time τ<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</i>. (3) down-scaling technologies, which reduce the parasitic base resistance and the base-collector (BC) junction capacitance, also helps to increasing the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i>. The device demonstrates a power density of 1.31 MW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, which is the highest for GaN HBTs on sapphire. These results underscore the potential of GaN HBTs for high-power, high-efficiency RF applications.

IEEE Electron Device LettersVol. 46(6)
Chinese Academy of Sciences (CN), China Academy of Engineering Physics (CN), Institute of Semiconductors (CN)
Affordable and clean energy
Openalex Percentile: Top 12%
GaN-based semiconductor devices and materials
2.52
DOISourceOpenAlex
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