Showing posts with label NQS. Show all posts
Showing posts with label NQS. Show all posts

Oct 25, 2023

[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.


Oct 5, 2020

[paper] TFT Compact Model of AMOLEDs Image‐Retention

A Novel Charge Based TFT Compact Model Applicable 
to Image‐Retention Simulation of AMOLEDs
Genshiro Kawachi 
Tianma Japan Ltd., Kanagawa, Japan
SID Symposium Digest of Technical Papers, 51(1), 1390–1393. 
P‐193: Late‐News‐Poster; First published: 25 September 2020
DOI: 10.1002/sdtp.14145

Abstract: A novel TFT compact model based on surface potential and charge calculations has been developed. Two kinds of non‐quasi‐static (NQS) models are included to describe the transient effects of TFTs. Appling the new model, accurate simulation of image retention phenomena in AMOLEDs was realized.
Fig: Transient response of a 2T1C pixel circuit (a) after switching from black to gray level: (b) simulation assuming a distributed τNQS model and measured results are compared.