A Study of the Shallow Electron Traps at the 4H-SiC/SiO&lt;sub&gt;2&lt;/sub&gt; Interface

Ólafsson, Halldór; Sveinbjörnsson, Einar Ö.; Rudenko, Tamara; Kilchytska, Valeriya; Tyagulski, I.P.; Osiyuk, I. N.

doi:10.4028/www.scientific.net/msf.433-436.547

Cited by 8 publications

(14 citation statements)

References 5 publications

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“…[11][12][13][14][15][16]18 A main focus in this section is to separate the TDRC signals coming from D it , NIT ox fast , and NIT ox slow , to determine their densities and energy distributions, and based on this knowledge to quantitatively explain the features of the C-V characteristics reported in the previous section. [11][12][13][14][15][16]18 A main focus in this section is to separate the TDRC signals coming from D it , NIT ox fast , and NIT ox slow , to determine their densities and energy distributions, and based on this knowledge to quantitatively explain the features of the C-V characteristics reported in the previous section.…”

Section: B Tdrc Spectramentioning

confidence: 99%

“…5. [13][14][15][16][17][18] Since no saturation is reached when increasing the accumulation bias up to the maximum values before failure occurs, the total amount of NIT ox centers in the samples cannot be determined. III A., for filling voltages lower than those corresponding to C FB in both type of samples no charge injection into the oxide takes place.…”

Section: B Tdrc Spectramentioning

confidence: 99%

“…Furthermore, only those D it with energy positions deep enough to be filled during these small charging biases will respond and in the following, they are denoted as deep D it . Previous studies have shown anomalously low effective capture cross sections for these states, [13][14][15][16] and therefore, values of smaller than 10 8 s −1 have to be considered when deducing the density versus energy distributions. 1͒.…”

Section: B Tdrc Spectramentioning

confidence: 99%

“…[2][3][4] Recently, various N + implantation processes of gate areas before wet oxidation treatments have been compared for the realization of Si face 4H-SiC n-MOSFETs. [13][14][15][16][17][18] The composition and structure of these near interface states are not yet clarified. High-low frequency capacitance-voltage ͑C-V͒ measurements performed on n-MOS capacitors at room temperature reveal 9,10 a strong reduction in the electron interface trap density near the conduction band in the samples with a high N concentration at the SiO 2 / SiC interface.…”

Section: Introductionmentioning

confidence: 99%

“…[5][6][7][8][9] The devices with the highest N concentration at the interface ͑ϳ1 ϫ 10 19 cm −3 ͒ present the highest channel mobility ͑22 cm 2 / V s͒, the lowest threshold voltage ͑2.4 V͒, and the smallest subthreshold swing ͑310 mV/decade at drain current of 10 −11 A͒. 17,19,20 These NIT ox have mainly been associated with a parallel shift in the C-V curves at low temperatures 14 while the defect states responsible for other features of the C-V curves ͑the shape and the frequency dependence͒ have received less attention so far. In this work we have employed comparative studies of gate oxides that have been grown on a N + preimplanted area and on a virgin Si face 4H-SiC material by means of C-V characteristics, performed at different temperatures and frequencies, and thermal dielectric relaxation current ͑TDRC͒ 11,12 technique.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of electron traps at the 4H–SiC/SiO2 interface; influence by nitrogen implantation prior to wet oxidation

Pintilie

Teodorescu

Moscatelli

et al. 2010

Journal of Applied Physics

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Density of interface states, electron traps, and hole traps as a function of the nitrogen density in SiO 2 on SiCInterfaces between 4H-SiC and Si O 2 : Microstructure, nanochemistry, and near-interface traps J. Appl. Phys. 97, 034302 (2005); 10.1063/1.1836004 Study on electron trapping and interface states of various gate dielectric materials in 4H-SiC metal-oxidesemiconductor capacitors Electron states at the SiO 2 / 4H -SiC interface have been investigated using capacitor structures and especially, the influence of excess nitrogen, introduced by ion implantation, at the interface is studied in detail. Implanted and nonimplanted n-type samples with an interfacial concentration of nitrogen of ϳ10 19 cm −3 and 10 16 cm −3 , respectively, were analyzed by capacitance-voltage ͑C-V͒ measurements, performed at different temperatures and probe frequencies, and thermal dielectric relaxation current ͑TDRC͒ measurements performed in the temperature range of 35-295 K. Three main categories of electron states are disclosed, true interface states ͑D it ͒, fast near interface states ͑NIT ox fast ͒ and slow near interface states ͑NIT ox slow ͒. The density versus energy distributions of D it and NIT ox fast have been deduced from the TDRC data and they are shown to give a close quantitative agreement with the shape and frequency dependence of the C-V curves. Further, the amount of NIT ox slow extracted from TDRC is demonstrated to be responsible for the parallel shifts and hysterezis effects occurring in the C-V characteristics. All three categories of electron states are reduced in concentration in the implanted samples. This holds particularly for NIT ox fast with a peak at ϳ0.1 eV below the conduction band edge of 4H-SiC that is suppressed by at least two orders of magnitude relative to the nonimplanted samples. The decrease for D it is also substantial ͑a factor of ϳ10͒ while the loss for NIT ox slow is considerably smaller ͑only ϳ30%͒. The results provide firm evidence that NIT ox fast and NIT ox slow do not originate from the same kind of defect center.

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Section: B Tdrc Spectramentioning

confidence: 99%

Section: B Tdrc Spectramentioning

confidence: 99%

Section: B Tdrc Spectramentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Analysis of electron traps at the 4H–SiC/SiO2 interface; influence by nitrogen implantation prior to wet oxidation

Pintilie

Teodorescu

Moscatelli

et al. 2010

Journal of Applied Physics

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Synergetic optimization of charge transport and breakdown strength of epoxy nanocomposites: Realizing sandwich topological structure through constructing a SiC@SiO2/EP surface layer and m-BNNS/EP insert layer

Xie

Gou

et al. 2022

Materials Science in Semiconductor Processing

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Interfaces between 4H-SiC and SiO2: Microstructure, nanochemistry, and near-interface traps

Pippel¹,

Woltersdorf²,

Ólafsson³

et al. 2004

Journal of Applied Physics

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118

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We report on electrical and microscopic investigations aimed to clarify the origin of near-interface traps (NITs) in metal-silicon dioxide-4H-silicon carbide structures. Using capacitance-voltage and thermal dielectric relaxation current (TDRC) analysis we investigated NITs close to the 4H-SiC conduction-band edge in differently prepared thermal and deposited oxides and found that the traps give rise to two characteristic TDRC signatures belonging to two groups of trap levels. The total trapped charge exceeds 1 ϫ 10 13 cm −2. The observed density and energy distribution of these traps are nearly identical in all thermal and deposited oxides investigated, suggesting that the NITs belong to intrinsic defects at the SiO 2 / SiC interface which are readily formed during oxide deposition or thermal oxidation of 4H-SiC. Using high-resolution electron microscopy combined with nanochemical analysis (electron energy-loss near-edge spectroscopy and energy-filtered transmission electron microscopy) we investigated the SiO 2 / SiC interface in samples receiving reoxidation and did not find any indication of graphitic regions at or near the SiO 2 / SiC interface or in the bulk silicon dioxide within a detection limit of 0.7 nm. In addition, no amorphous carbon accumulation was observed near the SiO 2 / SiC interface. The overall results strongly suggest that the NITs near the 4H-SiC conduction band are not related to carbon structures in the SiO 2 / SiC interlayer.

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A Study of the Shallow Electron Traps at the 4H-SiC/SiO<sub>2</sub> Interface

Cited by 8 publications

References 5 publications

Analysis of electron traps at the 4H–SiC/SiO2 interface; influence by nitrogen implantation prior to wet oxidation

Analysis of electron traps at the 4H–SiC/SiO2 interface; influence by nitrogen implantation prior to wet oxidation

Synergetic optimization of charge transport and breakdown strength of epoxy nanocomposites: Realizing sandwich topological structure through constructing a SiC@SiO2/EP surface layer and m-BNNS/EP insert layer

Interfaces between 4H-SiC and SiO2: Microstructure, nanochemistry, and near-interface traps

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