Horizontal Current Bipolar Transistor <i>f</i> <sub> <i>T</i> </sub> and <i>f</i> <sub> <i>max</i> </sub> Recovery at Cryogenic Temperatures

RF characterization of the Horizontal Current Bipolar Transistor (HCBT) is performed in a cryostat over the temperature range from 300 K down to 20 K. Following the expected decrease of small-signal current gain (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub>), cut-off frequency (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i>) and maximum frequency of oscillations (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i>) from 300 K to 80 K, a recovery of all parameters is observed below 80 K, in contrast to any other published Si BJT technology. Compared with a commercial bipolar junction transistor (BJT) having a similar <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> at 300 K, the HCBT demonstrates a 3.2 times higher <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i> and 2.5 times higher <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i> at 20 K. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i> recovery is attributed to the mobility improvement in the freeze-out regime, whereas <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i> increases even more due to the reduction of the effective collector-base capacitance (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C<sub>BC</sub></i>) below 80 K. These characteristics could facilitate the use of Si BJTs in cryogenic applications such as quantum computing.

Authors

Institutions

Publication Details

Journal
IEEE Electron Device Letters
Published
2025-10-03
DOI
https://doi.org/10.1109/led.2025.3617216
Primary Topic
Advancements in Semiconductor Devices and Circuit Design
Type
article
Field-Weighted Citation Impact
0.00
Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Horizontal Current Bipolar Transistor f T and f max Recovery at Cryogenic Temperatures

Tomislav Suligoj, Filip Bogdanović, Lovro Marković, M. Koričić et al.
IEEE Electron Device Letters
Advancements in Semiconductor Devices and Circuit Design
article

Horizontal Current Bipolar Transistor f T and f max Recovery at Cryogenic Temperatures

Tomislav Suligoj, Filip Bogdanović, Lovro Marković, M. Koričić, A. Tabaković
article en

Abstract

RF characterization of the Horizontal Current Bipolar Transistor (HCBT) is performed in a cryostat over the temperature range from 300 K down to 20 K. Following the expected decrease of small-signal current gain (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub>), cut-off frequency (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i>) and maximum frequency of oscillations (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i>) from 300 K to 80 K, a recovery of all parameters is observed below 80 K, in contrast to any other published Si BJT technology. Compared with a commercial bipolar junction transistor (BJT) having a similar <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> at 300 K, the HCBT demonstrates a 3.2 times higher <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i> and 2.5 times higher <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i> at 20 K. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>T</sub></i> recovery is attributed to the mobility improvement in the freeze-out regime, whereas <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f<sub>max</sub></i> increases even more due to the reduction of the effective collector-base capacitance (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C<sub>BC</sub></i>) below 80 K. These characteristics could facilitate the use of Si BJTs in cryogenic applications such as quantum computing.

IEEE Electron Device LettersVol. 46(12)
University of Zagreb (HR)
Openalex Percentile: Top 73%
Advancements in Semiconductor Devices and Circuit Design
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.