Query:  in SiC Power MOSFETs During Heavy-Ion Irradiation---Part II

Candidate papers:

abstract: This article presents the results of a 2 D finite element simulation study of the gate damages induced by heavy ion irradiation in SiC power metal oxide semiconductor field effect transistors (MOSFETs) The time evolution of the electric field in the gate oxide is studied. Two effects are investigated: the first is associated with the charge deposition in the SiC portion of the MOSFET, with the time evolution studied using the 2 D finite element simulator; the second one results from holes generated during the ion transit, trapped in the gate oxide after the fast electrons have been quickly swept away by the electric field. Two different techniques have been combined for estimating the hole concentration in the gate oxide: the well known recombination rate was modified to consider the trapped charge yield, as was recently done to better interpret single event gate rupture (SEGR) failure of silicon power MOSFETs. Under ion irradiation test conditions at which the gate damage experimentally starts to be observed, we demonstrate that, because of the ion impact, regardless of the ion linear energy transfer (LET) the peak value of the electric field in the gate oxide becomes practically equal to the oxide breakdown field ~12 15 MV/cm) Moreover, we show that simulations can be used to predict the test conditions at which gate damage starts to appear as a function of LET and the range of heavy ions used in the irradiation experiments.
author_names: Carmine Abbate

Giovanni Busatto

D Tedesco

Annunziata Sanseverino

Francesco Velardi

Jeffery Wyss
title: Gate Damages Induced in SiC Power MOSFETs During Heavy Ion Irradiation Part II
venue: IEEE Transactions on Electron Devices
year: 2019

abstract: Experimental characterization of the damage induced to SiC power MOSFETs by heavy ion irradiation is presented as a premise to a finite element simulation study aimed at gaining an insight into the physics of damage formation. Thanks to the new experimental setup, which is capable of accurately measuring the time evolution of the gate and drain leakage currents during irradiation, we herein demonstrate that the gate of a SiC power MOSFET is damaged by heavy ion irradiation at biasing drain voltages lower than 100 V, which is less than 10% of the nominal blocking voltage of the tested devices. The evolution of the gate and drain leakage currents during irradiation is explained considering that localized resistive paths due to damage sites are formed across the gate oxide. The results presented herein indicate the strong sensitivity of SiC power MOSFETs to gate rupture even if the main concern in the literature addressed so far is the rupture of the drain structure due to single event burnout.
author_names: Carmine Abbate

Giovanni Busatto

D Tedesco

Annunziata Sanseverino

L Silvestrin

Francesco Velardi

Jeffery Wyss
title: Gate Damages Induced in SiC Power MOSFETs During Heavy Ion Irradiation Part I
venue: IEEE Transactions on Electron Devices
year: 2019

abstract: Heavy ion induced single event burnout (SEB) is investigated in high voltage silicon carbide power MOSFETs. Experimental data for 1200 V SiC power MOSFETs show a significant decrease in SEB onset voltage for particle linear energy transfers greater than 10 MeV/cm2/mg, above which the SEB threshold voltage is nearly constant at half of the rated maximum operating voltage for these devices. TCAD simulations show a parasitic bipolar junction transistor turn on mechanism, which drives the avalanching of carriers and leads to runaway drain current, resulting in SEB.
author_names: Arthur F Witulski

Dennis R Ball

Kenneth F Galloway

Arto Javanainen

Jean-Marie Lauenstein

Andrew L Sternberg

Ronald D Schrimpf
title: Single Event Burnout Mechanisms in SiC Power MOSFETs
venue: IEEE Transactions on Nuclear Science
year: 2018

abstract: The transient response of Silicon Carbide (SiC) Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) with three different gates due to a single ion strike is studied. Comparing the experiment and numerical simulation, it is suggested that the charge enhancement is due to the bipolar effect. We find the bipolar gain depends on the quality of gate oxide. The impact of fixed charge in SiO2 and interface traps at SiC/SiO2 on the charge collection is discussed.
author_names: Shinobu Onoda

Takahiro Makino

Naoya Iwamoto

Gyorgy Vizkelethy

K Kojima

Shinji Nozaki

Takeshi Ohshima
title: Charge Enhancement Effects in 6H SiC MOSFETs Induced by Heavy Ion Strike
venue: IEEE Transactions on Nuclear Science
year: 2010

abstract: Heavy ion induced degradation and catastrophic failure data for SiC power MOSFETs and Schottky diodes are examined to provide insight into the challenge of single event effect hardening of SiC power devices.
author_names: Jean-Marie Lauenstein

Megan C Casey

Alyson D Topper

Edward P Wilcox

Anthony M Phan

Stanley A Ikpe

Kenneth A Label
title: Silicon Carbide Power Device Performance Under Heavy Ion Irradiation
year: 2015

abstract: The condition monitoring problem of power devices is significant for diagnostics and prognostics of a switched mode power supply (SMPS) system. For power mosfet, the gate oxide degradation often occurs in various applications. However, there is no online condition monitoring method for gate oxide degradation so far. In this paper, a new precursor that can be used for online condition monitoring of power mosfet gate oxide degradation is proposed. Gate oxide degradation mechanisms and effect are summarized, and the mosfet turn on process is analyzed. Then, a theoretical model is established to describe the relationship between miller platform voltage and two types of gate oxide defects, and miller platform voltage is identified as a new precursor. The precursor can be extracted without impacting system operation, thus online condition monitoring can be accomplished. The accelerated degradation test is carried out for power mosfets with both high electric field and gamma irradiation methods, and the degraded devices injection and in situ monitoring of miller platform voltage are conducted on a BOOST circuit to verify the feasibility of the new precursor. Experimental results demonstrate that the new precursor can be applied to online condition monitoring of power mosfet gate oxide degradation in the SMPS system.
author_names: Xuerong Ye

Cen Chen

Yixing Wang

Guofu Zhai

George J Vachtsevanos
title: Online Condition Monitoring of Power MOSFET Gate Oxide Degradation Based on Miller Platform Voltage
venue: IEEE Transactions on Power Electronics
year: 2017

abstract: Linear PA Design. Conventional High Efficiency Amplifier Modes. Class AB PAs at GHz Frequencies. Practical Design of Class AB PAs. Overdrive and the Class F Mode. Switching Mode Amplifiers for RF Applications. Switching PA Modes at GHz Frequencies. Signals, Modulation Systems, and PA Nonlinearities. Efficiency Enhancement Techniques. Power Amplifier Bias Circuit Design. Power Amplifier Architecture. PA Linearization Techniques.
author_names: Steve C Cripps
title: RF Power Amplifiers for Wireless Communications
year: 1999

abstract: Heavy ion induced single event burnout (SEB) is studied experimentally for several types of 4H SiC Schottky power diodes with various bias voltages applied. Safe operating voltage area for each type was defined and analyzed. The comparison with Si power devices was carried out.
author_names: P S Gromova

Georgii G Davydov

Alexander S Tararaksin

A S Kolosova

D V Boychenko

V N Vyuginov

Victor V Luchinin
title: Heavy Ion Induced Single Event Burnout in SiC Schottky Diodes: Safe Operating Area
venue: 2019 IEEE 31st International Conference on Microelectronics (MIEL)
year: 2019

abstract: SiC trench structures having a width of 0.6 mm and a depth of 2.0 mm are fabricated by reactive ion etching (RIE) using a gas mixture of SF6, Ar, and O2. Further, SiC trench structures are cleaved to expose the sidewall for the channel region of a trench MOSFET. These structures were analyzed by pin point photoelectron spectroscopy using a 100 nm soft X ray beam. It is observed that around 2 nm thick homogeneous carbon rich layer containing 1 2% F forms on the SiC sidewalls. This may be caused due to the re deposition of RIE reaction products, CF4 and SiF4, under appropriate conditions to fabricate the trench walls that are approximately vertical using RIE. Further, a carbon rich layer having a thickness of about 2.4 nm is also formed on the bottom of the SiC trench, suggesting the possibility of selective etching of Si from the SiC substrates. The position of the dominant peak that is associated with the SiC component remains constant regardless of the trench depth, suggesting homogeneous band bending due to the RIE defects, which may explain the reason for no variation being observed in the gate oxide/SiC interface trap density values. Further, the band bending of 1.50 eV that is observed on the sidewall can be attributed to a positively charged carbon vacancy (V+C) [DOI: 10.1380/ejssnt.2018.257]
author_names: Masaharu Oshima
title: Conference ISSS 8 Photoelectron Nano spectroscopy of Reactive Ion Etching Induced Damages to the Trench Sidewalls and Bottoms of 4 H SiC Trench MOSFETs
year: 2018

abstract: In 2011, after many years of research and development SiC power MOSFETs became available in the commercial marketplace. This paper presents the results of Co60 total ionizing dose (TID) effects for the new high power high current 24 A SiC devices irradiated at room temperature and 125degC. These commercially available components remained operational after a radiation dose of more than 100 krad. However, gamma ray irradiation gave rise to changes in current voltage and capacitance voltage characteristics. Specifically, threshold voltage decreased, resulting in increased current drive. We also observed rises in interface state densities, as well as input, output and reverse transfer capacitances with increasing accumulated doses.
author_names: Akin Akturk

James McGarrity

Siddharth Potbhare

Neil Goldsman
title: Radiation Effects in Commercial 1200 V 24 A Silicon Carbide Power MOSFETs
venue: IEEE Transactions on Nuclear Science
year: 2012