[paper] Sub-THz HICUM for SiGe HBTs

Soumya Ranjan Panda, Thomas Zimmer, Anjan Chakravorty, Nicolas Derrier

and Sebastien Fregonese

Exploring Compact Modeling of SiGe HBTs in Sub-THz Range With HICUM

in IEEE TED, DOI: 10.1109/TED.2023.3321017.

IMS laboratory, CNRS, University of Bordeaux (F)
Department of Electrical Engineering, IIT Madras (IN)
STMicroelectronics, 38920 Crolles (F)

Abstract : This study delves deeper into the high frequency (HF) behavior of state-of-the-art sub-THz silicon germanium heterojunction bipolar transistors (SiGe HBTs) fabricated with 55 nm BiCMOS process technology from STM. Using measurement data, calibrated TCAD simulations, and compact model simulations, we present a comprehensive methodology for extracting several HF parameters (related to parasitic capacitance partitioning and nonquasi-static effects) of the industry standard model, HICUM. The parameter extraction strategies involve thorough physics-based investigation and sensitivity analysis. The latter allowed us to precisely evaluate the effects of parameter variations on frequency dependent characteristics. The accuracy of the finally deployed model is tested by comparing the model simulation with measured small-signal two-port parameters of SiGe HBTs up to 330 GHz.

FIG: a.)  TEM image of the SiGe HBT device; b.) 2D TCAD structure simulation; c.) Large signal equivalent circuit of HICUM L2 compact model; d.) and e.) adjunct networks for vertical NQS effects

Acknowledgment: The authors would like to acknowledge Dider Celi, STM, for valuable discussion about the compact modeling of heterojunction bipolar transistors (HBTs), and they also like to thank STM for providing the silicon wafers. This work was supported by NANO2022 Important Project of Common European Interest Project (IPCEI), and SHIFT Grant ID 101096256.

[book chapters] Equation-Based Compact Modeling

 

Debnath, P., Sarkar, B., & Chanda, M. (Eds.). (2023).

Differential Equation Based Solutions 

for Emerging Real-Time Problems

(1st ed.). CRC Press 

DOI 10.1201/9781003227847

Chapter: Differential Equation-Based Compact 2-D Modeling of Asymmetric Gate Oxide Heterojunction Tunnel FET; By: Sudipta Ghosh, Arghyadeep Sarkar

Abstract: Tunnel Field Effect Transistor (TFET) has emerged as an effective alternative device to replace MOSFET for a few decades. The major drawbacks of MOSFET devices are the short-channel effects, due to which the leakage current increases with a decrease in device dimension. So, scaling down TFET is more efficacious than that of MOSFETs. Sub-threshold swing (SS) is another advantageous characteristic of TFET devices for high-speed digital applications. In TFETs the SS could be well below 60 mV/decade, which is the thermal limit for MOSFET devices and therefore makes it more suitable than MOSFET for faster switching applications. It is observed from the literature studies that the performances of the TFET devices have been explored thoroughly by using 2-D TCAD simulation but an analytical model is always essential to understand the physical behavior of the device and the physics behind this; which facilitates further, the analysis of the device performances at circuit level as and when implemented.

Chapter: Differential Equation-Based Analytical Modeling of the Characteristics Parameters of the Junctionless MOSFET-Based Label-Free Biosensors; by: Manash Chanda, Papiya Debnath, Avtar Singh

Abstract: Recently Field Effect transistor (FET)-based biosensing applications have gained significant attention due to the demand for quick and accurate diagnosis of different enzymes, proteins, DNA, viruses, etc; cost-effective fabrication process; portability and better sensitivity and selectivity compared to the existing biosensors. FET is basically a three-terminal device with source, drain, and gate terminals. Basically, the gate terminal controls the current flow between the source and drain terminals. In FETs, first, a nanogap is created in the oxide layer or in the gate by etching adequate materials. When the biomolecules are trapped inside the nanocavity then the surface potentials change and also the threshold voltage varies. As a result, the output current also changes. Finally, by measuring the changes in the threshold voltage or the device current, one can easily detect the biomolecules easily.

[paper] Perovskite Photodiodes

Dong Li and Anlian Pan

Perovskite sensitized 2D photodiodes

Light Sci Appl 12, 139 (2023)

DOI: 10.1038/s41377-023-01187-2

Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, China

Abstract: A new type of perovskite sensitized programmable WSe2 photodiode is constructed based on MAPbI3/WSe2 heterojunction, presenting flexible reconfigurable characteristics and prominent optoelectronic performances. The unique design of MAPbI3/WSe2 device provides a new idea to fabricate high-performance programmable photodiodes. In addition, the combination of atomic thin 2D materials and ionic solids enables effective coupling between electronic transport and ionic transport, which may open up a new pathway for unconventional computing, information storage systems, and programmable optoelectronic devices.

FIG: Schematic view of MAPbI3/WSe2 device structure and working mechanism 

of the programmable perovskite sensitized WSe2 photodiode