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Summarization: In this brief, extraction methods are proposed for determining the essential parameters of double gate junction field-effect transistors (FETs). First, a novel method for determining free carrier effective mobility, similar to a recently proposed method for MOSFETs, is developed. The same method is then extended to cover also the case when series resistance is present, while series resistance itself may be determined from the measurement from two FETs with different channel lengths. The key technological and design parameter is the threshold voltage, which may be unambiguously determined from the transconductance-to-current ratio with a constant-current method. The new methods are shown to be effective over a wide range of technical parameters, using technology computer-aided design simulations. Presented on: IEEE Transactions on Electron Devices

Summarization: The design of radiation-hard analog/mixed signal Integrated Circuits for high Total Ionizing Dose (TID) is a challenging task. Front-end electronics for the High-Luminosity Large Hadron Collider (HL-LHC) are expected to be exposed to doses exceeding 500 Mrad(SiO2). Using a recently developed TID-Process Design Kit (PDK) in 65 nm bulk CMOS, the present paper illustrates the design of micropower, current-mirror and folded cascode CMOS Operational Transconductance Amplifiers (OTAs) using moderate inversion techniques to favor insensitivity to high TID. Παρουσιάστηκε στο: 8th International Conference on Modern Circuits and Systems Technologies

Summarization: Frond-end electronics at the High Luminosity-Large Hadron Collider (HL-LHC) at CERN, will be exposed to ten-fold radiation doses. The use of enclosed gate (EG) MOSFETs of 65 nm Bulk CMOS process, is considered to be a viable solution in order to suppress performance degradation effects that occur after high TID exposure. The present paper presents a detailed analysis of the functionality of EG MOSFETs operating under high TID, taking into accountspecific layout characteristics. Παρουσιάστηκε στο: 26th International Conference "Mixed Design of Integrated Circuits and Systems"

Summarization: High doses of ionizing radiation drastically impair the electrical performance of CMOS technology. Enclosed gate layout remains an effective means to reduce this impact. Nevertheless, high total ionizing dose (TID) effects remain strong. The paper presents an effective approach to analytically model high TID effects in both NMOS and PMOS transistors with enclosed-gate layout in 65 nm commercial CMOS. Παρουσιάστηκε στο: 41st International Semiconductor Conference

Summarization: Ten-fold radiation levels are expected in the upgrade of the High-Luminosity Large Hadron Collider (HL-LHC) at CERN. Bulk silicon CMOS at 65 nm offers appreciable advantages among cost, performance, and resilience to high Total Ionizing Dose (TID). In the present paper, geometrical scaling of key analog design parameters of MOS transistors irradiated at high TID is investigated. Experiments are carried out for TID of 100, 200 and up to 500 Mrad(SiO2) and at -30°C, 0°C, and 25°C. We find that parameters are least degraded at -30°C. However, short-channel NMOSTs show a significant degradation of slope factor, which is more severe at 0°C than at 25°C. In contrast, the slope factor in short-channel PMOSTs shows lowest sensitivity to high TID. Παρουσιάστηκε στο: 25th International Conference ""Mixed Design of Integrated Circuits and Systems""

Summarization: High doses of ionizing irradiation cause significant shifts in design parameters of standard bulk silicon CMOS. Analog performance of a commercial 65 nm CMOS technology is examined for standard and enclosed gate layouts, with Total Ionizing Dose (TID) up to 500 Mrad(SiO2). The paper provides insight into geometrical and bias dependence of key design parameters such as threshold voltage, DIBL, transconductance efficiency, slope factor, and intrinsic gain. A modeling approach for an efficient representation of saturation transfer characteristics under TID from weak through moderate and strong inversion and over channel length is discussed. Παρουσιάστηκε στο: IEEE International Conference on Microelectronic Test Structures

Two challenging fields of semiconductor applications are the field of high-energy physics experiments, as a hostile operating environment for deep sub-micron MOSFETs and the field of high-precision, low-noise analog design with its requirements for detailed and accurate MOSFET noise models. An analysis is presented on MOS devices irradiated to ultrahigh radiation doses, as part of the viability study conducted at CERN in cooperation with TUC for the upcoming LHC upgrade due in 2025-2027. Our part was to analyze, characterize and model the damage inflicted on a specific commercially available 65nm bulk CMOS technology, in order to allow designers at CERN to properly use it for the predicted ten year lifespan of the experiment. To this end, we have presented in this work selected operational parameters of interest to designers, which were extracted for both MOS polarities, multiple VTH device types, at three different temperatures, down to -30° C, at four different irradiation levels, up to 500Mrad. Multiple device geometries were studied and are presented. Furthermore, measurements and analysis of the noise response of a commercially available 110nm bulk CMOS technology is demonstrated. The system and methodology for on-wafer noise measurements is presented along with our efforts in extracting and analyzing usable data from our measurements. The EKV3 parameter extraction approach using the two distinct incorporated noise models is also described. Our resulting measurements are presented for the three different MOS polarities provided for this task. Output as well as input referred noise spectra are presented, fitted with an analytical flicker noise model., Δύο διαφορετικά πεδία εφαρμογών των ημιαγωγών, με τις ιδιαίτερα ξεχωριστές τους προκλήσεις, είναι το πεδίο πειραμάτων φυσικής υψηλών ενεργειών, ως ένα πολύ εχθρικό περιβάλλον λειτουργίας για τρανζίστορ MOSFET υπο-μικρομετρικών διαστάσεων και το πεδίο της αναλογικής σχεδίασης υψηλής ακριβείας και χαμηλού θορύβου με τις απαιτήσεις του για λεπτομερή και ακριβή μοντέλα θορύβου για τρανζίστορ MOSFET. Παρουσιάζεται ανάλυση πάνω σε διατάξεις MOS που ακτινοβολήθηκαν σε υπερ-υψηλές δόσεις ακτινοβολίας, ως μέρος της μελέτης καταλληλότητας που διεξήχθη στο CERN σε συνεργασία με το Πολυτεχνείο της Κρήτης για την επερχόμενη αναβάθμιση του LHC κατά τα έτη 2025-2027. Δική μας εργασία ήταν το να αναλύσουμε, χαρακτηρίσουμε και μοντελοποιήσουμε τη ζημία που επέρχεται σε μια συγκεκριμένη εμπορικά διαθέσιμη τεχνολογία 65nm bulk CMOS, ώστε να επιτραπεί στους σχεδιαστές στο CERN να την αξιοποιήσουν κατάλληλα για όλη τη δεκαετή προβλεπόμενη διάρκεια του πειράματος. Προς το σκοπό αυτό παρουσιάσαμε σε αυτή την εργασία συγκεκριμένες λειτουργικές παραμέτρους που ενδιαφέρουν τους σχεδιαστές, οι οποίες εξήχθησαν για τις δύο πολικότητες MOS, τους τύπους διατάξεων διαφορετικής τάσης κατωφλίου, σε τρεις διαφορετικές θερμοκρασίες, έως και -30°C, σε τέσσερα διαφορετικά επίπεδα δόσης, έως και 500Mrad. Πολλές διαφορετικές γεωμετρίες μελετήθηκαν και παρουσιάζονται. Επιπρόσθετα, επιδεικνύεται η μέτρηση και ανάλυση της απόκρισης θορύβου μιας εμπορικά διαθέσιμης τεχνολογίας 110nm bulk CMOS. Παρουσιάζεται το σύστημα και η μεθοδολογία για την διεξαγωγή μετρήσεων θορύβου πάνω σε δισκία πυριτίου, μαζί με τη διαδικασία που ακολουθήσαμε για να εξαγάγουμε αξιοποιήσιμα δεδομένα από τις μετρήσεις μας καθώς και να τα αναλύσουμε. Περιγράφεται επίσης η προσέγγιση του ζητήματος εξαγωγής παραμέτρων μοντέλου EKV3, με τα δύο διαφορετικά ενσωματωμένα μοντέλα θορύβου. Οι μετρήσεις θορύβου παρουσιάζονται για τις τρεις πολικότητες που είχαμε διαθέσιμες για αυτόν το σκοπό. Παρουσιάζονται φάσματα θορύβου αναφερόμενου στην έξοδο καθώς και στην είσοδο, στα οποία έχει εφαρμοστεί ένα αναλυτικό μοντέλο θορύβου χαμηλής συχνότητας.

Summarization: Standard CMOS Process Design Kits (PDKs) do not address degradation the technology incurs when exposed to high Total Ionizing Dose (TID). Front-end electronics for the High-Luminosity Large Hadron Collider are expected to be exposed up to ten-fold doses. Bulk CMOS at 65 nm is a strong contender for such electronics due to a favorable trade-off among cost, performance, and TID-sensitivity. The present paper presents the extension of a foundry-provided PDK to cover also high TID effects. TID experiments have been carried out up to 500 Mrad. The PDK is based on binned BSIM4 models, which are adapted to different TID levels. Hence, designers may choose among different TID levels for their designs, contributing importantly to radiation-hard design practice. Παρουσιάστηκε στο: 7th International Conference on Modern Circuits and Systems Technologies

Summarization: This paper presents a novel charge-based approach to modeling bias-dependent noise in junction field-effect transistors (JFETs). Low frequency noise as well as thermal noise aspects are modeled within the recent charge-based model of the double-gate (DG) JFET. For low frequency noise, mobility fluctuations according to the Hooge model is addressed. Thermal noise is expressed within the charge-based modeling approach. The models are validated with respect to TCAD simulations and show correct dependence over a range of gate and drain bias. A custom setup for low frequency noise measurement of JFETs is described. Noise measurements of n-JFETs are discussed, and the compact model is compared with the measurement. Presented on