Title: Optimisation of extrinsic base doping of a SiGe heterojunction bipolar transistor integrated in a BiCMOS 55 nm technology for high frequency performances

Authors: C.G. Lachkhab; M. Lakhdara; A. Boulgheb; S. Latreche

Addresses: University of Frères Mentouri Constantine 1 (UFMC), P.O. Box 25017, Constantine, Algeria; Laboratory Hyper frequency and Semi-conductors (LHS), Department of Electronics, Algeria ' University of Frères Mentouri Constantine 1 (UFMC), P.O. Box 25017, Constantine, Algeria; Laboratory Hyper frequency and Semi-conductors (LHS), Department of Electronics, Algeria ' University of Frères Mentouri Constantine 1 (UFMC), P.O. Box 25017, Constantine, Algeria; Laboratory Hyper frequency and Semi-conductors (LHS), Department of Electronics, Algeria ' University of Frères Mentouri Constantine 1 (UFMC), P.O. Box 25017, Constantine, Algeria; Laboratory Hyper frequency and Semi-conductors (LHS), Department of Electronics, Algeria

Abstract: This work presents an optimisation of the frequency performance of a new technology of a SiGe heterojunction bipolar transistor (HBT), realised in an industrial BiCMOS55 process technology with a double poly-silicon, self-aligned, selective epitaxial growth (DPSA-SEG) architecture, produced by ST microelectronics. This technology features high attractive performances (fT/fmax = 320/370 GHz). The simulation results are produced by using 2D COMSOL Multiphysics software, based on the drift diffusion model (DDM) and interface semiconductor. Our findings concentrated on the optimisation of the intrinsic and extrinsic base doping on the dynamic properties of HBT. The doping of the extrinsic base significantly affects the frequencies fT and fmax of the HBT compared to the doping of the intrinsic base. The maximum oscillation frequency reached was fmax = 630 GHz for a doping of 2.1019 cm-3of the poly silicon base (extrinsic base) whereas the transition frequency climbed to fT = 351. 6 GHz for the same extrinsic base doping.

Keywords: HBT; heterojunction bipolar transistor; BiCMOS055; SiGe; Comsol; DDM; drift diffusion model; frequency; intrinsic base; extrinsic base.

DOI: 10.1504/IJNT.2023.135816

International Journal of Nanotechnology, 2023 Vol.20 No.11/12, pp.1017 - 1026

Published online: 05 Jan 2024 *

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