Cyclotron Resonance Studies of Effective Masses and Band Structure in SiC

We investigated the effects of the interface state density (DIT) at the interfaces between SiO2 and the Si-, C-, and a-faces of 4H-SiC in n-channel metal-oxide-semiconductor field-effect transistors that were subjected to dry/nitridation and pyrogenic/hydrotreatment processes. The interface state density over a very shallow range from the conduction band edge (0.00 eV < EC − ET) was evaluated on the basis of the subthreshold slope deterioration at low temperatures (11 K < T). The interface state density continued to increase toward EC, and DIT at EC was significantly higher than the value at the conventionally evaluated energies (EC − ET = 0.1–0.3 eV). The peak field-effect mobility at 300 K was clearly inversely proportional to DIT at 0.00 eV, regardless of the crystal faces and the oxidation/annealing processes.

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“…19,23 The calculated DOS is plotted in Fig. 6(b), and is shown to be significantly less than D IT near E C .…”

Section: Discussionmentioning

confidence: 97%

N-channel field-effect mobility inversely proportional to the interface state density at the conduction band edges of SiO2/4H-SiC interfaces

et al. 2015

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“…Here,

m_{ML}^{*}

m_{M Γ}^{*}

, and

m_{MK}^{*}

are the effective masses along each direction in the Brillouin zone. A previous study has reported these values simply at the bottom of the conduction band (

E_{normalC}

) (

m_{ML}^{*} = 0.33 m_{0}

m_{M Γ}^{*} = 0.58 m_{0}

, and

m_{MK}^{*} = 0.31 m_{0}

where

m_{0}

is the electron rest mass [ 13 ] ), and

m_{⊥}^{*} / m_{/ /}^{*}

E_{normalC}

has been obtained as 1.21, as depicted in Figure 3 by the dashed line. While the μ ratio at 140 K is close to this value, it gradually deviates from 1.21 at higher temperatures.…”

Section: Resultsmentioning

confidence: 85%

“…The results for higher

N_{normalD}

are plotted in darker colors. The dashed line depicts the ratio of the electron effective mass at

E_{normalC}

(

m_{⊥}^{*} / m_{/ /}^{*} = 1.21

), [ 13 ] and the solid line shows that of averaged effective mass (

m_{⊥, ave}^{*} / m_{/ /, ave}^{*}

) calculated by considering the energy dependence of the electron effective mass (Figure 4c).…”

Section: Resultsmentioning

confidence: 99%

“…In addition, the direction dependence of the mobility should be considered as well, especially in 4H-SiC. The hexagonal crystal structure of 4H-SiC causes anisotropic physical properties such as the effective mass, [11][12][13] the dielectric constant, [14,15] the impact ionization coefficient, [16][17][18] and the thermal conductivity. [19] Electron mobility has also been reported to exhibit anisotropy by several experiments [20][21][22][23][24][25] and the electron mobility along the h0001i direction (c-axis) shown in Figure 1 is known to be higher than that perpendicular to the c-axis.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Theoretical Study on Anisotropic Electron Mobility in 4H‐SiC

Ishikawa

Tanaka

Kaneko

et al. 2023

Physica Status Solidi (b)

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Electron mobility parallel to the c‐axis in 4H‐SiC was experimentally determined by Hall effect measurements over wide donor density and temperature ranges (6 × 1014–3 × 1018 cm−3 and 140–600 K), and it was compared with that perpendicular to the c‐axis obtained for the same conditions. Empirical equations for the mobility along both directions were determined as functions of donor density and temperature, which contribute to the simulation and designing of SiC devices. The origin of the mobility anisotropy was discussed focusing on the electron effective mass anisotropy. For a precise analysis taking into account the effect of electrons at a higher energy region than the conduction band bottom, an averaged electron effective mass considering the energy distribution was theoretically calculated from the band structure of SiC. As a result, we clarified that the electron mobility anisotropy including its temperature dependence is well explained by the averaged electron effective mass anisotropy.This article is protected by copyright. All rights reserved.

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“…The latter is dependent upon the density of states in the materials, which for SiC is quite complex [23,24]. Both e 1 and m ⁄ also depend on the particular polytype of SiC, the polarization of the incident radiation, and, in the case of m ⁄ , the free carrier type (electron or hole).…”

Section: Theorymentioning

confidence: 99%

Notes on the plasma resonance peak employed to determine doping in SiC

Engelbrecht

Rooyen

Henry

et al. 2015

Infrared Physics & Technology

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h i g h l i g h t sThe article provides a review of past research and information about the plasma resonance in silicon carbide. Attention was given to all parameters involved for the three most common polytypes of SiC. The second plasma resonance was investigated. An explanation for not observing the 2nd plasma minimum in 3C-SiC is provided. a b s t r a c tThe doping level of a semiconductor material can be determined using the plasma resonance frequency to obtain the carrier concentration associated with doping. This paper provides an overview of the procedure for the three most common polytypes of SiC. Results for 3C-SiC are presented and discussed. In phosphorus doped samples analysed, it is submitted that the 2nd plasma resonance cannot be detected due to high values of the free carrier damping constant c.

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Cyclotron Resonance Studies of Effective Masses and Band Structure in SiC

Cited by 8 publications

References 42 publications

N-channel field-effect mobility inversely proportional to the interface state density at the conduction band edges of SiO2/4H-SiC interfaces

N-channel field-effect mobility inversely proportional to the interface state density at the conduction band edges of SiO2/4H-SiC interfaces

Experimental and Theoretical Study on Anisotropic Electron Mobility in 4H‐SiC

Notes on the plasma resonance peak employed to determine doping in SiC

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