[paper] DC, LF noise and TID mechanisms in 16nm FinFETs

Stefano Bonaldo^ab, Teng Ma^ab, Serena Mattiazzo^bc, Andrea Baschirotto^de, Christian Enz^f, Daniel M.Fleetwood^g, Alessandro Paccagnella^ab, Simone Gerardin^ab

DC response, low-frequency noise, and TID-induced mechanisms in 16-nm FinFETs for high-energy physics experiments

J. NIMA Section A; available online 18 April 2022, 166727

DOI: j.nima.2022.166727

     
a University of Padova (I)
b INFN Padova (I)
c University of Padova (I)
d INFN Milano (I)
e University of Milano Bicocca (I)
f ICLab, EPFL, Lausanne (CH)
g Vanderbilt University, Nashville (USA)

Abstract: Total-ionizing-dose (TID) mechanisms are evaluated in 16nm Si bulk FinFETs at doses up to 1 Grad (SiO₂) for applications in high-energy physics experiments. The TID effects are evaluated through DC and low-frequency noise measurements by varying irradiation bias conditions, transistor channel lengths, and fin/finger layouts. The TID response of nFinFETs irradiated under positive gate bias at ultrahigh doses shows a rebound of threshold voltage with significant increase in the 1/f noise amplitude. The degradation is related to the generation of border and interface traps at the upper corners of STI oxides and at the gate oxide/channel interfaces. In contrast, pFinFETs have the worst degradation due to positive charge trapping in STI oxides, which severely degrades the device transconductance and total drain current, while negligible effects are visible in the threshold voltage and 1/f noise. The TID sensitivity depends strongly on the transistor layout. Short-channel devices have the best TID tolerance thanks to the influence of halo implantation, while pFinFETs designed with low number of fins have the worst degradation because of high densities of positive charge in the surrounding thick STI oxides. As a guideline for IC design, short-channel transistors with more than 4-fins may be preferred in order to facilitate circuit qualification.

Fig: Low-frequency noise measured at |Vds|=50mV and |Vgs|=0.85V at room temperature for pFinFET with Nfin=2 and L=16 nm, irradiated up to 1Grad (SiO2) in the ON condition

Acknowledgment: This work has been carried out within the FinFET16v2 experiment funded by the National Institute for Nuclear Physics - INFN, Italy.

[paper] Noise Degradation and Recovery in Gamma-irradiated SOI nMOSFET

S.Amora^b, V.Kilchytska^a, F.Tounsi^a, N.André^a, M.Machhout^b, L.A.Francis^a, D.Flandre^a

Characteristics of noise degradation and recovery in gamma-irradiated SOI nMOSFET

with in-situ thermal annealing

Solid-State Electronics; 108300; online 7 April 2022, 

DOI: 10.1016/j.sse.2022.108300

   
a SMALL, ICTEAM Institute, Université catholique de Louvain (B)
b Faculté des Sciences de Université de Monastir (TN)

Abstract: This paper demonstrates a procedure for complete in-situ recovery of on-membrane CMOS devices from total ionizing dose (TID) defects induced by gamma radiation. Several annealing steps were applied using an integrated micro-heater with a maximum temperature of 365°C. The electrical characteristics of the on-membrane nMOSFET are recorded prior and during irradiation (up to 348 krad (Si)), as well as after each step of the in-situ thermal annealing. High-resolution current sampling measurements reveal the presence of oxide defects after irradiation, with a clear dominant single-trap signature in the random telegraph noise (RTN) traces. Drain current over time measurements are used for the trap identification and further for the defects' parameters extraction. The power spectral density (PSD) curves confirm a clear dominance of the RTN behavior in the low-frequency noise. A radiation-induced oxide trap is detected at 5.4 nm from the Si-SiO2 interface, with an energy of 0.086 eV from the Fermi level in the bandgap. After annealing, the RTN behavior vanishes with a further important reduction of flicker noise. Low-frequency noise measurements of the transistor confirmed the neutralization of oxide defects after annealing. The electro-thermal annealing of the nMOSFET allows a total recovery of its original characteristics after being severely degraded by radiation-induced defects.

Fig: Device under test : (a) cross-section schematic, (b) microscopic front view

showing the membrane and other embedded elements

Compact Transistor Modeling with Radiation Effects

A Radiation-Hardened Instrumentation Amplifier for Sensor Readout Integrated Circuits in Nuclear Fusion Applications

Kyungsoo Jeong 1, Duckhoon Ro 1, Gwanho Lee 2  Myounggon Kang 2* and Hyung-Min Lee 1*

1 School of Electrical Engineering, Korea University, Seoul 02841, Korea; jksoo2002@korea.ac.kr (K.J.); roduckhoon@korea.ac.kr (D.R.)

2 Department of Electronics Engineering, Korea National University of Transportation, Chungju 27469, Korea; ghlee@ut.ac.kr

* Correspondence: mgkang@ut.ac.kr (M.K.); hyungmin@korea.ac.kr (H.-M.L.); Tel.: +82-43-841-5164 (M.K.); +82-2-3290-3219 (H.-M.L.)

Abstract: A nuclear fusion reactor requires a radiation-hardened sensor readout integrated circuit (IC), whose operation should be tolerant against harsh radiation effects up to MGy or higher. This paper proposes radiation-hardening circuit design techniques for an instrumentation amplifier (IA), which is one of the most sensitive circuits in the sensor readout IC. The paper studied design considerations for choosing the IA topology for radiation environments and proposes a radiation-hardened IA structure with total-ionizing-dose (TID) effect monitoring and adaptive reference control functions. The radiation-hardened performance of the proposed IA was verified through model-based circuit simulations by using compact transistor models that reflected the TID effects into complementary metal–oxide–semiconductor (CMOS) parameters. The proposed IA was designed with the 65 nm standard CMOS process and provides adjustable voltage gain between 3 and 15, bandwidth up to 400 kHz, and power consumption of 34.6 µW, while maintaining a stable performance over TID effects up to 1 MGy.

Electronics 2018, 7, 429; doi:10.3390/electronics7120429
Received: 22 November 2018; Accepted: 9 December 2018; Published: 12 December 2018