[Habilitation] Assessment of novel devices in CMOS technology

Assessment of novel devices in CMOS technology

by electrical characterization and physics-based model

Habilitation Presented To Obtain The Authorization 

To Direct Research From Sorbonne University

Lionel Trojman, PhD

Sorbonne Université, 2020

Organization of the thesis

Chapter 1: This chapter extends research work after the author’s PhD study. It focuses on HfO2-based dielectric MOSFETs with sub-1nm EOT. The study explores the impact of transport factors like saturation velocity on planar MOSFETs and the mobility of FDSOI-UTBB MOSFETs. Notably, the back-biased effect is considered, and an inversion charge model is developed for different front and back biases.

Chapter 2: Emphasis the application of the statistical defect-centric model to assess the impact of channel hot carriers on the reliability of low-dimensional MOSFETs.

Chapter 3: This chapter shifts focus to GaN-on-Si wafer devices for power electronic applications. These devices integrate MOS-like structures into III-V material-based devices, specifically MOS-HEMT and GET-SBD.

Chapter 4: Investigates RERAM devices. It stems from cooperative research with UNICAL and a PhD program in collaboration with Aix-Marseille University

FIG: Description of the gate structure (half device) of the studied device including the parasitic capacitance inner fringing (CIF), outer fringe (COF) and Junction overlap capacitance (COV)

 

 

[thesis] RF UTBB FDSOI MOSFET

Vanbrabant, Martin

RF characterization of the back-gate contact on Fully Depleted SOI MOSFETs

http:// hdl.handle.net/2078.1/thesis:26763

Ecole polytechnique de Louvain, Université catholique de Louvain, 2020. 

Academic year 2019–2020: Master in Electrical Engineering

Prom.: Prof. Jean-Pierre Raskin

Readers: Denis Flandre, Valeriya Kilchytska, Lucas Nyssens, Martin Rack

Abstract: Thanks to the thin buried-oxide, the UTBB FDSOI technology with a highly doped region under the BOX is one of the main candidates for future RF applications. One of the most interesting feature of this technology is the possibility to tune the threshold voltage, compensate variability issues and improve the overall device performance. In this work, the impact of the back-gate bias is mainly studied on the threshold voltage and RF FoMs of the front and back-gates.

Figure: Reconstructed (dashed) vs initial (full) Re{Yij} insaturationat VDS=0.8V, VGS=0.8V and VB=0V for a 4-port device.

[paper] Electrical characterization of advanced MOSFETs

Valeriya Kilchytska, Sergej Makovejev, Babak Kazemi Esfeh, Lucas Nyssens, Arka Halder,

Jean-Pierre Raskin and Denis Flandre

Electrical characterization of advanced MOSFETs towards analog and RF applications

IEEE LAEDC, San Jose, Costa Rica, 2020, 

doi: 10.1109/LAEDC49063.2020.9073536

Abstract - This invited paper reviews main approaches in the electrical characterization of advanced MOSFETs towards their target analog and RF applications. Advantages and necessity of those techniques will be demonstrated on different study cases of various advanced MOSFETs, such as FDSOI, FinFET, NW in a wide temperature range, based on our original research over the last years. 

URL: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9073536&isnumber=9072949

Acknowledgements - This work was partially funded by Eniac “Places2Be”, Ecsel “Waytogofast”, FNRS - FRFC “Towards Highly-efficient 10 nm MOSFETs”, FP7 “Nanosil” and “Nanofunction” projects. The authors thank our colleagues from CEA-Leti, ST and Imec, and particularly, F. Andrieu, O. Faynot, T. Poiroux, S. Barraud, M. Haond, N. Planes, N. Collaert, C. Claeys, M. Jurczak, B. Parvais, R. Rooyackers, for providing UTBB FD SOI, NW and FinFET devices and valuable discussions.

[MOS-AK/DATE 2015 Workshop] CEA-Leti's predictive model takes FDSOI further

 CEA-Leti's predictive model takes FDSOI further 

During DATE 2015’s MOS-AK Workshop, CEA-Leti presented the newest version of its advanced compact model for ultra-thin body and buried oxide fully depleted SOI (UTBB-FDSOI) technology.

Fully Depleted Silicon On Insulator (FDSOI) is a planar process technology that relies on two primary innovations. First, an ultra-thin layer of insulator, called the buried oxide, is positioned on top of the base silicon.

Then, a very thin silicon film implements the transistor channel. Thanks to its thinness, there is no need to dope the channel, thus making the transistor fully depleted. The combination of these two innovations is called “ultra-thin body and buried oxide Fully Depleted SOI” or UTBB-FDSOI.

Back in 2013, CEA-Leti had deployed a first compact model, but working in close cooperation with STMicroelectronics, the research lab understood that more subtle back gate channelling effects had to be addressed to fully exploit the benefits of UTBB-FDSOI and to explore the transistors’ behaviour in more details.

New analytical equations were written from scratch for the Leti-UTSOI2.1 compact model, improving on the predictability and accuracy capabilities of the previous version, Leti-UTSOI2.

To date, other models from the University of Hiroshima, and from the University of Berkeley fail to account for inversion effects at the back interface, when a strong forward back bias (FBB) is applied, told us Thierry Poiroux, Leti research engineer and model co-developer.

More specifically, the French lab used a unique analytical resolution scheme for the calculation of surface potentials at both interfaces of the transistor body, offering a refined description of narrow-channel effects, with an improved accuracy of moderate inversion regime and gate tunnelling current modelling.

Because the model is analytical, it is much faster than any numerical simulation. It is now available in all major SPICE and Fast SPICE simulators through licences with EDA vendors and will allow fabless companies and IC designers to virtually explore different UTBB-FDSOI parameters within a given foundry process node. The new model can also be used by foundries and fabless companies to perform a predictive analysis of future nodes to come, in order to orient their ongoing process optimization.

for more information visit CEA-Leti at www.leti.fr