[paper] SPICE Modeling of a Radiation Sensor

Miloš Marjanović 1, Stefan D. Ilić 2, Sandra Veljković 1, Nikola Mitrović 1, Umutcan Gurer 3, Ozan Yilmaz 3, Aysegul Kahraman 4, Aliekber Aktag 3, Huseyin Karacali 3, Erhan Budak 3, Danijel Danković 1, Goran Ristić 1 and Ercan Yilmaz 3

The SPICE Modeling of a Radiation Sensor Based on a MOSFET

with a Dielectric HfO2/SiO2 Double-Layer

Sensors 2025, 25(2), 546; DOI:10.3390/s25020546

1 Department of Microelectronics, Faculty of Electronic Engineering, University of Niš, Serbia
2 Center of Microelectronic Technologies, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Serbia
3 Faculty of Arts and Sciences, Bolu Abant Izzet Baysal University, Turkey
4 Department of Physics, Faculty of Arts and Sciences, Bursa Uludag University, Turkey

Abstract: We report on a procedure for extracting the SPICE model parameters of a RADFET sensor with a dielectric HfO2/SiO2 double-layer. RADFETs, traditionally fabricated as PMOS transistors with SiO2, are enhanced by incorporating high-k dielectric materials such as HfO2 to reduce oxide thickness in modern radiation sensors. The fabrication steps of the sensor are outlined, and model parameters, including the threshold voltage and transconductance, are extracted based on experimental data. Experimental setups for measuring electrical characteristics and irradiation are described, and a method for determining model parameters dependent on the accumulated dose is provided. A SPICE model card is proposed, including parameters for two dielectric thicknesses: (30/10) nm and (40/5) nm. The sensitivities of the sensors are 1.685mV/Gy and 0.78mV/Gy, respectively. The model is calibrated for doses up to 20Gy, and good agreement between experimental and simulation results validates the proposed model.

FIG: (a) Block diagram of the radiation source setup; 

(b) radiation setup in the TENMAK lab.

The corresponding SPICE model card is presented below:

.MODEL RADFET PMOS VTO={if(TYPE==1,-0.493-(1.54e-3*DOSE),-0.65433-(7.54E-4*DOSE))}

+KP={if(TYPE==1,8.897e-6-(1.493e-8*DOSE),1.14E-5-(2.511E-9*DOSE))} L=50e-6 W=600e-6

+TPG=0 LAMBDA={if(TYPE==1,3.901E-2-(2.165E-4*DOSE),2.0115E-2-(1.8575E-4*DOSE))}

Acknowledgements: This research was funded by North Atlantic Treaty Organization (NATO) SPS MYP under grant number G5974, by the project “High-k Dielectric RADFET for Detection of RN Treats”, and supported by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia [grant number 451-03-65/2024-03/200102 and grant number 451-03-66/2024-03/200026].

[CI Inovador] OpenPDK Introduction

INOVA-ME: Curso de Capacitação, Inovação, Gestão e Empreendedorismo em Microeletrônica

INOVA-ME é um dos polos de capacitação do Programa CI Inovador financiado pelo MCTI e coordenado pela Softex , executado pelo Instituto de Informática da Universidade Federal do Rio Grande do Sul (INF-UFRGS).

The OpenPDK Introduction is part of the CI Inovador course, 

scheduled for January 24, 2025, from 13:30 to 15:00 BRT.

The conference call platform is MCONF, accessible via the following link: https://mconf.ufrgs.br/webconf/inova-me

Agenda:

---

1. General Introduction and Technical Presentation (1 hour)

Wladek Grabinski: General introduction to FOSS EDA/CAD and OpenPDK (20-25 minutes)

Dr. Wladek Grabinski, a distinguished expert with over 30 years of international experience in semiconductor R&D, compact modeling, and custom IC design. Currently, leading engineering R&D at GMC Consulting, and supports IHP OpenPDK Initiative. Dr. Grabinski has worked with renowned institutions such as EPFL, Motorola, and Freescale. He is an accomplished author of multiple books on analog/RF modeling and a recognized leader in developing advanced SPICE models for nanoscale CMOS technologies. Dr. Grabinski's contributions continue to shape the field of analog and RF IC design in the OpenPDK domain.

Krzysztof Herman: Technical OpenPDK presentation, 

including design demos and an IHP overview (20-25 minutes)

Dr. Krzysztof Herman, a research associate specializing in OpenPDK development at IHP in Germany. With over a decade of experience, including roles as a professor and researcher in Europe and Latin America, Dr. Herman has expertise spanning telecommunications, ASIC design, and FPGA development. He has also contributed to Antarctic and polar research expeditions, showcasing his multidisciplinary approach and dedication to advancing both science and technology.

Q&A: 10 minutes

2. OpenPDK Brazil Discussion and Demonstration (30 minutes)

Francisco Brito: Real chip design demonstration using IHP OpenPDK (10-12 minutes)

Dr. Francisco Brito Filho, UFERSA, Professor and Head of the LIEB/LAMERF Research Labs. Dr. Brito holds a PhD in RF Microelectronics and has extensive expertise in RF/AMS IC design, instrumentation, and biomedical engineering. With experience in academia, industry, and entrepreneurship, Dr. Brito has worked on innovative projects ranging from CMOS-based RFICs to advanced biomedical equipment. His leadership and technical excellence continue to drive impactful research and development in microelectronics. He is already teaching microelectronics classes using OpenPDK and OpenSource tools.

Q&A: 3 minutes

Juan Brito: OpenPDK Brazil Discussion (10-12 minutes)

Dr. Juan Brito has over two decades in Semiconductors and Integrated Circuits, deep expertise in device engineering, analog design, and advanced IC testing. Dr. Brito has passion for continuous development is evidenced by contributions to academic publications and involvement in international student exchange programs. He is lookin for new challenges that leverage technical and managerial expertise to drive innovation and sustainable growth in the semiconductor industry particularly in the OpenPDK domain.

Q&A: 3 minutes

[paper] Nanowire Biosensor Analytical Model

Ashkhen Yesayan, Aleksandr Grabski, Farzan Jazaeri, Jean-Michel Sallese

Design-Oriented Analytical Model for Nanowire Biosensors Including Dynamic Aspects

IEEE TED (2025) DOI 10.1109/TED.2025.3526113

Abstract: Nanowire Field Effect Transistor (NWFET) biosensors are known to be highly sensitivity devices that can detect extremely low concentrations of biomolecules. In this paper, we present an analytical model alongside with numerical simulations to calculate the sensitivity of NWFET biosensors. The model accounts for biosensing dynamics as well as diffusion of ions in the solution and across the functionalized layer. The signal-to-noise ratio is also estimated, which gives a lower limit in terms of sensitivity. The model is physics based and is validated against a commercial multiphysics simulations and experimental data. It predicts the bio-sensitivity down to femtomolar concentration of biomolecules without any fitting parameter.

FIG: Schematic structure of device (a), the charge distribution in theoretical model (b) 

and Si NWFET sensitivity simulated with presented model (c)

Acknowledgement: This work was supported by the Science Committee of RA, in the frames of the research project No:21T-2B321.

SwissChips: foster the Swiss semiconductor ecosystem

SwissChips is an inital three-year transitional measure jointly led by the Swiss Center for Electronics and Microtechnology (CSEM), EPFL and ETH, aimed to maintain and secure a strong position of Swiss researchers and research infrastructure in the strategically important areas of semiconductor technologies, microelectronics, and more specifically cutting-edge integrated circuit (IC) design within the European landscape [read more...]

[paper] Spatz: open-source RISC-V compact VPU

Matteo Perotti, Samuel Riedel, Matheus Cavalcante and Luca Benini^1,2

Spatz: Clustering Compact RISC-V-Based Vector Units to Maximize Computing Efficiency

arXiv:2309.10137v2 [cs.AR] 9 Jan 2025

1 IIS, ETH Zurich (CH)
2 DEI, Uni. Bologna (IT)

Abstract: The ever-increasing computational and storage requirements of modern applications and the slowdown of technology scaling pose major challenges to designing and implementing efficient computer architectures. To mitigate the bottlenecks of typical processor-based architectures on both the instruction and data sides of the memory, we present Spatz, a compact 64-bit floating-point-capable vector processor based on RISC-V’s Vector Extension Zve64d. Using Spatz as the main Processing Element (PE), we design an open-source dual-core vector processor architecture based on a modular and scalable cluster sharing a Scratchpad Memory (SCM). Unlike typical vector processors, whose Vector Register Files (VRFs) are hundreds of KiB large, we prove that Spatz can achieve peak energy efficiency with a latch-based VRF of only 2 KiB. An implementation of the Spatz-based cluster in GlobalFoundries’ 12LPP process with eight double-precision Floating Point Units (FPUs) achieves an FPU utilization just 3.4% lower than the ideal upper bound on a double-precision, floating-point matrix multiplication. The cluster reaches 7.7 FMA/cycle, corresponding to 15.7 GFLOPSDP and 95.7 GFLOPSDP/W at 1 GHz and nominal operating conditions (TT, 0.80 V, 25 °C), with more than 55% of the power spent on the FPUs. Furthermore, the optimally-balanced Spatz-based cluster reaches a 95.0% FPU utilization (7.6 FMA/cycle), 15.2 GFLOPSDP, and 99.3 GFLOPSDP/W (61% of the power spent in the FPU) on a 2D workload with a 7 × 7 kernel, resulting in an outstanding area/energy efficiency of 171 GFLOPSDP/W/mm2. At equi-area, the computing cluster built upon compact vector processors reaches a 30% higher energy efficiency than a cluster with the same FPU count built upon scalar cores specialized for streambased floating-point computation.

Fig: Placed-and-routed Spatz-based shared-L1 cluster, implemented as a 737 μm × 1003 μm block. The cluster’s main blocks are highlighted: namely the Snitch cores, VRFs, IPUs, FPUs, L1 SPM, and I$.

Acknowledgment: This work was supported in part through the TRISTAN (#101095947) and the ISOLDE (#101112274) projects, both funded through the Chips Joint Undertaking (CHIPS JU) of the European Union’s Horizon Europe’s research and innovation programme and its members.