Poole-Frenkel Research Articles

Leakage current transport mechanism under reverse bias in Au/Ni/GaN Schottky barrier diode

The leakage current transport mechanism under reverse bias of Au/Ni/GaN Schottky diode is studied using temperature dependent current-voltage (I-V-T) and capacitance-voltage (C-V) characteristics. I-V measurement in this study is in the range of 140 K–420 K in steps of 10 K. A reduction in voltage dependent barrier height and a strong internal electric field in depletion region under reverse bias suggested electric field enhanced thermionic emission in carrier transport via defect states in Au/Ni/GaN SBD. A detailed analysis of reverse leakage current revealed two different predominant transport mechanisms namely variable-range hopping (VRH) and Poole-Frenkel (PF) emission conduction at low (<260 K) and high (>260 K) temperatures respectively. The estimated thermal activation energies (0.20–0.39 eV) from Arrhenius plot indicates a trap assisted tunneling of thermally activated electrons from a deep trap state into a continuum of states associated with each conductive threading dislocation.

Study of structural and electrical properties of Ag-starch nanocomposites

ABSTRACTIn the present work, Ag nanoparticles prepared by chemical reduction were used to synthesize Ag-starch nanocomposites. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to ascertain the formation of Ag-starch nanocomposites. Current-voltage (I-V) measurements reveal that the conductivity of starch increases with increasing concentration of Ag nanoparticles. I-V data was further analysed to ascertain the actual conduction mechanism responsible for charge transport in starch and Ag-starch nanocomposites. Poole-Frenkel (PF) emission was found to be dominant conduction mechanism responsible for increased conductivity of Ag-starch nanocomposites.

The electron trap parameter extraction-based investigation of the relationship between charge trapping and activation energy in IGZO TFTs under positive bias temperature stress

Experimental extraction of the electron trap parameters which are associated with charge trapping into gate insulators under the positive bias temperature stress (PBTS) is proposed and demonstrated for the first time in amorphous indium-gallium-zinc-oxide thin-film transistors. This was done by combining the PBTS/recovery time-evolution of the experimentally decomposed threshold voltage shift (ΔVT) and the technology computer-aided design (TCAD)-based charge trapping simulation. The extracted parameters were the trap density (NOT) = 2.6×1018 cm−3, the trap energy level (ΔET) = 0.6 eV, and the capture cross section (σ0) = 3 × 10−19 cm2.Furthermore, based on the established TCAD framework, the relationship between the electron trap parameters and the activation energy (Ea) is comprehensively investigated. It is found that Ea increases with an increase in σ0, whereas Ea is independent of NOT. In addition, as ΔET increases, Ea decreases in the electron trapping-dominant regime (low ΔET) and increases again in the Poole–Frenkel (PF) emission/hopping-dominant regime (high ΔET). Moreover, our results suggest that the cross-over ΔET point originates from the complicated temperature-dependent competition between the capture rate and the emission rate. The PBTS bias dependence of the relationship between Ea and ΔET suggests that the electric field dependence of the PF emission-based electron hopping is stronger than that of the thermionic field emission-based electron trapping.

Mechanism of oxide thickness and temperature dependent current conduction in n+-polySi/SiO2/p-Si structures — a new analysis

The conduction mechanism of gate leakage current through thermally grown silicon dioxide (SiO2) films on (100) p-type silicon has been investigated in detail under negative bias on the degenerately doped n-type polysilicon (n+-polySi) gate. The analysis utilizes the measured gate current density JG at high oxide fields Eox in 5.4 to 12 nm thick SiO2 films between 25 and 300 °C. The leakage current measured up to 300 °C was due to Fowler–Nordheim (FN) tunneling of electrons from the accumulated n +-polySi gate in conjunction with Poole Frenkel (PF) emission of trapped-electrons from the electron traps located at energy levels ranging from 0.6 to 1.12 eV (depending on the oxide thickness) below the SiO2 conduction band (CB). It was observed that PF emission current IPF dominates FN electron tunneling current IFN at oxide electric fields Eox between 6 and 10 MV/cm and throughout the temperature range studied here. Understanding of the mechanism of leakage current conduction through SiO2 films plays a crucial role in simulation of time-dependent dielectric breakdown (TDDB) of metaloxide–semiconductor (MOS) devices and to precisely predict the normal operating field or applied gate voltage for lifetime projection of the MOS integrated circuits.

Mechanistic analysis of temperature-dependent current conduction through thin tunnel oxide in n+-polySi/SiO2/n+-Si structures

We present a detailed investigation on temperature-dependent current conduction through thin tunnel oxides grown on degenerately doped n-type silicon (n+-Si) under positive bias (VG) on heavily doped n-type polycrystalline silicon (n+-polySi) gate in metal-oxide-semiconductor devices. The leakage current measured between 298 and 573 K and at oxide fields ranging from 6 to 10 MV/cm is primarily attributed to Poole-Frenkel (PF) emission of trapped electrons from the neutral electron traps located in the silicon dioxide (SiO2) band gap in addition to Fowler-Nordheim (FN) tunneling of electrons from n+-Si acting as the drain node in FLOating gate Tunnel OXide Electrically Erasable Programmable Read-Only Memory devices. Process-induced neutral electron traps are located at 0.18 eV and 0.9 eV below the SiO2 conduction band. Throughout the temperature range studied here, PF emission current IPF dominates FN electron tunneling current IFN at oxide electric fields Eox between 6 and 10 MV/cm. A physics based new analytical formula has been developed for FN tunneling of electrons from the accumulation layer of degenerate semiconductors at a wide range of temperatures incorporating the image force barrier rounding effect. FN tunneling has been formulated in the framework of Wentzel-Kramers-Brilloiun taking into account the correction factor due to abrupt variation of the energy barrier at the cathode/oxide interface. The effect of interfacial and near-interfacial trapped-oxide charges on FN tunneling has also been investigated in detail at positive VG. The mechanism of leakage current conduction through SiO2 films plays a crucial role in simulation of time-dependent dielectric breakdown of the memory devices and to precisely predict the normal operating field or applied floating gate (FG) voltage for lifetime projection of the devices. In addition, we present theoretical results showing the effect of drain doping concentration on the FG leakage current.

Rectifying electronic transport and the role of Fowler-Nordheim tunneling in Ag/PVDF/Au capacitor structures

The electron transport through β phase dominant Polyvinylidene fluoride (PVDF) thin films in its intrinsic form is investigated and reports the stable rectification up to ±30 V in Ag/PVDF/Au capacitor structures. A practical resistance ratio of ∼40 between −1 V and 1 V and a maximum ratio of ∼77 at −24 V and 24 V exhibits its potential usage in selector devices. Furthermore, the nonpolar electronic transport is analysed with Schottky, Space Charge Limited Current (SCLC), Poole-Frenkel (PF) and Fowler-Nordheim (FN) tunneling mechanisms with respect to electrode, thickness and temperature variations.

Dielectric Properties of and Charge Transport in Columnar Microfibrous Thin Films of Parylene C

Parylene-C microfibrous thin films ( $\mu $ FTFs), grown using oblique-angle physicochemical vapor deposition, were examined for potential use as low-relative-permittivity (i.e., low- $\kappa $ ) interlayer dielectrics in integrated circuits and, more importantly, flexible electronics. These films were characterized using capacitance–voltage–temperature (CVT) and current–voltage–temperature experiments at different temperatures (ranging from 298 to 420 K) and frequencies (ranging from 1 kHz to 1 MHz). Field emission scanning electron microscopy revealed the Parylene C $\mu $ FTFs to be highly porous. Consequently, their $\kappa $ values are at least 20% lower than those of bulk Parylene C. The dependences of $\kappa $ on frequency and temperature suggest that molecular dipole oscillations are responsible for charge polarization in the $\mu $ FTFs. The dc leakage current in the $\mu $ FTFs at temperatures not exceeding 100 °C (~373 K) was found to arise from Poole–Frenkel (PF) emissionmechanism with a barrier energy of about 0.77 eV. Moreover, when fitted to the PF model, the experimental data yielded high-frequency values $\kappa _{\infty }$ of $\kappa $ in agreement with those obtained from CVT experiments, thus confirming our identification of PF as themajor responsiblemechanism and confirming the low- $\kappa $ characteristic of microfibrous Parylene C. The ac current transport in the $\mu $ FTFs was found attributable to small-polaron-tunneling hopping conduction and characterized by the power law $ \omega ^{s}$ , with $s\in [{0.082,0.85}]$ increasing with temperature. AC conduction in the $\mu $ FTFs is temperature-activated with an activation energy that decreases from 0.020 to 0.012 eV as frequency increases from 1 kHz to 1 MHz.

Fabrication of multi-layer Bi2Se3 devices and observation of anomalous electrical transport behaviors

In this paper, we report on the fabrication of multi-layer bismuth selenide (Bi2Se3) devices by lithography process and their electrical transport characteristics studied at room temperature. The observation of a non-linear current-voltage characteristic is analyzed with various current transport mechanisms such as Schottky barrier, space-charge limited conduction (SCLC), Fowler-Nordheim (F-N) tunneling and Poole-Frenkel (P-F) conduction. The F-N tunneling via field emission current induced in high-voltage was found to be the dominant conduction mechanism which could responsible for the nonlinear behavior as compared to SCLC and P-F conduction phenomena. The charge traps present in the Bi2Se3 bulk causes SCLC and P-F conduction. A carrier mobility in Bi2Se3 is extracted as ~ 1220cm2V−1s−1. Our study further advances the understanding of the fundamental charge transport mechanisms appeared in Bi2Se3 which will be an essential parameter in the development of various electronic applications such as resistive memory switching and sensing devices.

Current conduction mechanisms through thin tunnel oxide during erase operation of flash electrically erasable programmable read-only memory devices

The mechanism of current conduction through thin tunnel oxide during erase operation of flash electrically erasable programmable read-only memory devices has been studied both theoretically and experimentally. The floating gate (FG) leakage current measured between 25 and 300 °C and at oxide fields ranging from 6 to 10 MV/cm is primarily attributed to Poole–Frenkel (PF) emission of trapped electrons from the electron traps located at about 1.0 eV below the silicon dioxide conduction band in addition to Fowler–Nordheim (FN) tunneling of electrons from the degenerately doped n-type polycrystalline silicon (n+-polySi) FG. It is observed that PF emission current IPF dominates FN electron tunneling current IFN at oxide electric fields Eox between 6 and 10 MV/cm and throughout the temperature range studied here. The observed thickness dependence of FG leakage current at a given applied oxide field arises due to different electron trap concentrations in the oxide. A physics based new temperature dependent analytical formula has also been developed for FN tunneling of electrons from the accumulation layer of semiconductors. In addition, the authors present theoretical results showing the effect of the FG doping concentration on the leakage current.

Contrasting conduction mechanisms of two internal barrier layer capacitors: (Mn, Nb)-doped SrTiO3 and CaCu3Ti4O12

The d.c. conduction is investigated in the two different types of internal barrier layer capacitors, namely, (Mn, Nb)-doped SrTiO3 (STO) and CaCu3Ti4O12 (CCTO). Scanning electron microscopy (SEM) and Capacitance - Voltage (C-V) analysis are performed to estimate the effective electric field at a grain boundary, EGB. Then, the d.c. conduction mechanism is discussed based on the J (Current density)-EGB characteristics. Three different conduction mechanisms are successively observed with the increase of EGB in both systems. In (Mn, Nb)-doped STO, non-linear J-EGB characteristics is temperature dependent at the intermediate EGB and becomes relatively insensitive to the temperature at the higher EGB. The J- EGB at each regime is explained by the Schottky emission (SE) followed by Fowler-Nordheim (F-N) tunneling. Based on the F-N tunneling, the breakdown voltage is then scaled by the function of the depletion layer thickness and Schottky barrier height at the average grain boundary. The proposed function shows a clear linear relationship with the breakdown. On the other hand, F-N tunneling was not observed in CCTO in our measurement. Ohmic, Poole-Frenkel (P-F), and SE are successively observed in CCTO. The transition point from P-F and SE depends on EGB and temperature. A charge-based deep level transient spectroscopy study reveals that 3 types of trap states exist in CCTO. The trap one with Et ∼ 0.65 eV below the conduction band is found to be responsible for the P-F conduction.

A Comprehensive Study of Reverse Current Degradation Mechanisms in Au/Ni/n-GaN Schottky Diodes

In this paper, we perform a comprehensive study on the reverse current degradation mechanisms in Au/Ni/n-GaN Schottky diodes based on an in-depth understanding on the defect-related current transport mechanisms. Instead of traditional Poole–Frenkel (PF) emission model, an extended bulk-limited PF transport process, including the compensation effect, is adopted to explain the variation of the PF current slope as a function of the stress time, which majorly takes place inside the depletion region near the neutral semiconductor side. Based on the electrostatic analysis, we develop a shallow donor-like defects model to address the current degradation kinetics, which states that the energetic electrons produced by Fowler–Nordheim tunneling can induce significant Joule heating effect during the subsequent drift move of field, and give rise to the formation of the donor-like defects, and in turn enhance the surface electrical field to cause a significant increase of the tunneling component, in good agreement with the emission microscope observations.

Leakage current conduction, hole injection, and time-dependent dielectric breakdown of n-4H-SiC MOS capacitors during positive bias temperature stress

The conduction mechanism(s) of gate leakage current JG through thermally grown silicon dioxide (SiO2) films on the silicon (Si) face of n-type 4H-silicon carbide (4H-SiC) has been studied in detail under positive gate bias. It was observed that at an oxide field above 5 MV/cm, the leakage current measured up to 303 °C can be explained by Fowler-Nordheim (FN) tunneling of electrons from the accumulated n-4H-SiC and Poole-Frenkel (PF) emission of trapped electrons from the localized neutral traps located at ≈2.5 eV below the SiO2 conduction band. However, the PF emission current IPF dominates the FN electron tunneling current IFN at oxide electric fields Eox between 5 and 10 MV/cm and in the temperature ranging from 31 to 303 °C. In addition, we have presented a comprehensive analysis of injection of holes and their subsequent trapping into as-grown oxide traps eventually leading to time-dependent dielectric breakdown during electron injection under positive bias temperature stress (PBTS) in n-4H-SiC metal-oxide-silicon carbide structures. Holes were generated in the heavily doped n-type polycrystalline silicon (n+-polySi) gate (anode) as well as in the oxide bulk via band-to-band ionization by the hot-electrons depending on their energy and SiO2 film thickness at Eox between 6 and 10 MV/cm (prior to the intrinsic oxide breakdown field). Transport of hot electrons emitted via both FN and PF mechanisms was taken into account. On the premise of the hole-induced oxide breakdown model, the time- and charge-to-breakdown (tBD and QBD) of 8.5 to 47 nm-thick SiO2 films on n-4H-SiC were estimated at a wide range of temperatures. tBD follows the Arrhenius law with activation energies varying inversely with initial applied constant field Eox supporting the reciprocal field (1/E) model of breakdown irrespective of SiO2 film thicknesses. We obtained an excellent margin (6.66 to 6.33 MV/cm at 31 °C and 5.11 to 4.55 MV/cm at 303 °C) of normal operating field for a 10-year projected lifetime of 8.5 to 47 nm-thick SiO2 films on n-4H-SiC under positive bias on the n+-polySi gate. Furthermore, the projected maximum operating oxide field was little higher in metal gate devices compared to n+-polySi gate devices having an identically thick thermal SiO2 films under PBTS.

Simulation of Gate Leakage Current of AlGaN/GaN HEMTs: Effects of the Gate Edges and Self-Heating

The gate leakage current (IG) of AlGaN/GaN high electron mobility transistors (HEMTs) at various ambient temperatures is simulated by considering its mechanism as domination of trap-assisted tunneling (TAT) and Poole-Frenkel (PF) emission for low electric field in the AlGaN barrier, and domination of Fowler–Nordheim (FN) tunneling for high electric field in the AlGaN barrier. Two bias cases are studied: VGS (gate voltage) variation while VDS (drain voltage) = 0 V without self-heating and VDS variation while VGS = 0 V with self-heating. For the first case, FN tunneling current mainly concentrates near the gate edges and so it is not changed with the gate length. While PF emission and TAT current do not show big variation along the gate, they are affected by the gate length and show higher values for longer gate. For the second case, with VDS increasing the elevated device temperature caused by the self-heating obviously increases PF emission and also increases IG because PF emission is the dominant mechanism of IG. With VDS further increasing, although the higher device temperature presents, IG is not affected by the self-heating because the temperature-independent FN tunneling becomes the dominant mechanism of IG.

Effects of electrode on resistance switching properties of ZnMn2O4 films deposited by magnetron sputtering

ZnMn2O4 films for resistance random access memory (RRAM) were fabricated with different device structures by magnetron sputtering. The effects of electrode on I-V characteristics, resistance switching behavior, endurance and retention characteristics of ZnMn2O4 films were investigated. The ZnMn2O4 films, using p-Si and Pt as bottom electrode, exhibit bipolar resistive switching (BRS) behavior dominated by the space-charge-limited conduction (SCLC) mechanism in the high resistance state (HRS) and the filament conduction mechanism in the low resistance state (LRS), but the ZnMn2O4 films using n-Si as bottom electrodes exhibit both bipolar and unipolar resistive switching behaviors controlled by the Poole-Frenkel (P-F) conduction mechanism in both HRS and LRS. Ag/ZnMn2O4/p-Si device possesses the best endurance and retention characteristics, in which the number of stable repetition switching cycle is over 1000 and the retention time is longer than 106 seconds. However, the highest RHRS/RLRS ratio of 104 and the lowest VON and VOFF of 3.0 V have been observed in Ag/ZnMn2O4/Pt device. Though the Ag/ZnMn2O4/n-Si device also possesses the highest RHRS/RLRS ratio of 104, but the highest values of VON,VOFF, RHRS and RLRS, as well as the poor endurance and retention characteristics.

Bipolar resistive switching and conduction mechanism of an Al/ZnO/Al-based memristor

In this study, a direct-current reactive sputtered Al/ZnO/Al-based memristor device was fabricated and its resistive switching (RS) characteristics investigated. The optical and structural properties were confirmed by using UV–vis spectrophotometry and x-ray diffraction, respectively. The memristive and resistive switching characteristics were determined using time dependent current–voltage (I-V-t) measurements. The typical pinched hysteresis I-V loops of a memristor were observed. In addition, the device showed forming-free, uniform and bipolar RS behavior. The low electric field region exhibited ohmic conduction, while the Schottky emission (SE) was found to be the dominant conduction mechanism in the high electric field region. A weak Poole-Frenkel (PF) emission also appeared. In conclusion, it was suggested that the SE and PF mechanisms were related to the oxygen vacancies in the ZnO.

Electrical characteristics and conduction mechanisms of amorphous subnanometric Al2O3–TiO2 laminate dielectrics deposited by atomic layer deposition

Electric conduction mechanisms of amorphous Al2O3/TiO2 (ATO)-laminates deposited by atomic layer deposition with sub-nanometer individual layer thicknesses were studied in a large temperature range. Two characteristic field regions are identified. In the low field region (E ≤ 0.31 MV/cm), the leakage current is dominated by the trap-assisted tunneling through oxygen vacancies occurring in the TiO2, while in the high electric field region (E &amp;gt; 0.31 MV/cm) the Poole Frenkel (PF) hopping is the appropriate conduction process with energy levels depending on the temperature and the electric field. It is shown that the PF potential levels decrease with the applied ATO field due to the overlapping of the Coulomb potential. Amorphous ATO-laminates show the presence of two intrinsic potential energy levels ϕi, which are 0.18 eV for low temperature region and 0.4 eV at high temperature region. Oxygen vacancies are the main origin of traps, which is consistent with the principal mechanisms for leakage in ATO-laminates.

Observation of temperature effect on electrical properties of novel Au/Bi0.7Dy0.3FeO3/ZnO/p-Si thin film MIS capacitor for MEMS applications

In this work the dependence of electrical properties on operation temperature (27°C to 200°C) of Au-Cr/Bi0.7Dy0.3FeO3 (BDFO)/ZnO/p-Si (MIS device) are discussed. The thin film of BDFO was deposited by pulsed laser deposition (PLD) on p-Si. From the electrical characterization, the devices properties like ideality factor (η), barrier height) (BH) of Au-Cr/BDFO/ZnO/p-Si MIS were determined. The values of η and BH were found to be 1.34 and 0.86eV at 200°C and 2.16 and 0.30eV; respectively, at room temperature (27°C). The leakage current conduction mechanism of the device was investigated and found to be Schottky emission (SE) in the low electric field (<0.92MVcm−1) regime and trap assisted Poole–Frenkel (PF) mechanism for high electric field regime. The coexistence of ferroelectric and ferromagnetic coupling and excellent dielectric properties in multiferroic BDFO offers potential in the field of memory devices; sensing and energy harvesting (cantilevers).

A compact model of the reverse gate-leakage current in GaN-based HEMTs

The gate-leakage behavior in GaN-based high electron mobility transistors (HEMTs) is studied as a function of applied bias and temperature. A model to calculate this current is given, which shows that trap-assisted tunneling, trap-assisted Frenkel-Poole (FP) emission, and direct Fowler-Nordheim (FN) tunneling have their main contributions at different electric field regions. In addition, the proposed model clearly illustrates the effect of traps and their assistance to the gate leakage. We have demonstrated the validity of the model by comparisons between model simulation results and measured experimental data of HEMTs, and a good agreement is obtained.

(Invited) Understanding the Structure and Electrical Response of Combined Threshold and Memristive Switching Devices Obtained from Amorphous Nb2O5 Layers

Redox-based resistive switching cells (ReRAM) are intensively studied for next generation non-volatile memory due to simple device structure, low power consumption, and good endurance.[1] High density integration demands for technologies like three dimensional (3D) stacking and 4F 2 crossbar array architectures.[2] However, passive ReRAM arrays require the integration of bidirectional selector devices with high selectivity to suppress sneak-path currents.[3] A promising concept is based on threshold-type devices as obtained from NbO2, which typically show a negative differential resistance (NDR) characteristic.[4] This volatile resistance change can be utilized for the realization of a highly non-linear selector element. The presentation comprises two studies. The first one addresses the fabrication and nano-scale characterization of combined threshold and memory cells (TS-ReRAM) with a potential for future high-density 3D integration. The cells are built from a 10 nm thick amorphous Nb2O5 layer grown by atomic layer deposition (ALD) and integrated into Pt/Nb2O5/Ti/Pt nano-crossbar structures. After electroforming, the devices combine the functions of volatile threshold and non-volatile memresistive switching. The structural changes induced by the electroforming step are analyzed by means of electron nano-diffraction. The results confirm the formation of crystalline NbO2 within a small regime localized inside the Nb2O5-x based switching cell.[5] This finding supports the proposal of an Nb2O5-x/NbO2 filament being the central element of the TS-ReRAM cell. The second study aims upon a deeper understanding of the threshold switching (TS) phenomenon in NbO2-based TS-ReRAM devices. A widely accepted model for TS in NbO2 is based on a combination of Joule heating and an insulator to metal transition (IMT) at TIMT , NbO2 ≈ 1080 K.[6] This model, however, leads to fundamental contradictions like a too low discontinuity in the I-V characteristics. Recently it has been shown that an increase in temperature of about 200 K is sufficient to suppress the TS-effect.[7] Therefore we set-up a two-dimensional axial symmetric simulation of the TS-behavior of the Nb2O5-x / NbO2 based cells.[8] The continuum model includes a filamentary switching, divided into a threshold and a memristive switching region. The fully coupled heat transfer and continuity equation system is solved by Newton-Raphson iteration. The conduction mechanism for the threshold regime is based on a Poole Frenkel (PF) like barrier lowering and exponentially coupled to the electric field. The interplay of Joule heating and an increase of conducting charge carriers causes an electric field controlled thermal runaway process, which is interrupted by the resistance of the memory in low resistance state limiting further Joule heating. The proposed model reproduces the experimental results fairly well. [8] The understanding of the structural modifications associated with the electroforming and resistive switching process in NbO2/Nb2O5-x based TS-ReRAM cells makes the fabrication of such devices by means of the ALD technique feasible. In addition, our proposed two dimensional simulation based on an electric field triggered thermal runaway (FTTR) mechanism provides a deeper understanding of the switching limitations in the TS-ReRAM structures. Additionally, the realization of Boolean logic functionality using the TS-ReRAM devices has been demonstrated.[9] This work was supported in part by the Deutsche Forschungsgemeinschaft (SFB917), and by FP7 under grant ENHANCE-238409.

Simulation of temperature dependent dielectric breakdown in n+-polySi/SiO2/n-6H-SiC structures during Poole-Frenkel stress at positive gate bias

We present for the first time a thorough investigation of trapped-hole induced gate oxide deterioration and simulation results of time-dependent dielectric breakdown (TDDB) of thin (7–25 nm) silicon dioxide (SiO2) films thermally grown on (0 0 0 1) silicon (Si) face of n-type 6H-silicon carbide (n-6H-SiC). Gate oxide reliability was studied during both constant voltage and current stress with positive bias on the degenerately doped n-type poly-crystalline silicon (n+-polySi) gate at a wide range of temperatures between 27 and 225 °C. The gate leakage current was identified as the Poole-Frenkel (PF) emission of electrons trapped at an energy 0.92 eV below the SiO2 conduction band. Holes were generated in the n+-polySi anode material as well as in the oxide bulk via band-to-band ionization depending on the film thickness tox and the energy of the hot-electrons (emitted via PF mechanism) during their transport through oxide films at oxide electric fields Eox ranging from 5 to 10 MV/cm. Our simulated time-to-breakdown (tBD) results are in excellent agreement with those obtained from time consuming TDDB measurements. It is observed that irrespective of stress temperatures, the tBD values estimated in the field range between 5 and 9 MV/cm better fit to reciprocal field (1/E) model for the thickness range studied here. Furthermore, for a 10 year projected device lifetime, a good reliability margin of safe operating field from 8.5 to 7.5 MV/cm for 7 nm and 8.1 to 6.9 MV/cm for 25 nm thick SiO2 was observed between 27 and 225 °C.