Initial stages of SiC oxidation investigated by ion scattering and angle-resolved x-ray photoelectron spectroscopies

Radtke, C.; Baumvol, Israel Jacob Rabin; Morais, Jonder; Stedile, Fernanda Chiarello

doi:10.1063/1.1374518

Cited by 67 publications

(50 citation statements)

References 17 publications

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“…The clean sample presents a small amount of silicon bonded to oxygen and/or carbon in different stoichiometries, named silicon oxycarbides compounds (SiC x O y ), which could not be removed with wet etching in HF, attributed to the high chemical stability of these compounds against wet environments. 16 In the first stage of oxidation investigated, mainly these SiC x O y are formed, in agreement with previous work, 17 which are not adequate to be used as an insulator layer prior to the SiO 2 film deposition. As oxidation progresses in time, stoichiometric SiO 2 becomes the main compound observed.…”

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confidence: 85%

The Role Played in the Improvement of the SiO2/SiC Interface by a Thin SiO2 Film Thermally Grown Prior to Oxide Film Deposition

Pitthan

Palmieri

Corrêa

et al. 2012

ECS Solid State Letters

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To minimize electrical degradation from thermal oxidation of 4H-SiC, a thin and stoichiometric SiO 2 film was thermally grown, monitored by X-ray photoelectron spectroscopy. To obtain thicker films, SiO 2 was deposited by sputtering. Reduction in the flatband voltage was observed when compared to SiO 2 films thermally grown or deposited directly on 4H-SiC. Post-deposition annealing in Ar reduced the flatband voltage of the samples but induced an electrical degradation in the SiO 2 /4H-SiC interface. Nuclear reaction analyzes proved that the thin film thermally grown was not stable during the annealing, exchanging O atoms with the deposited film and with the gaseous ambient.

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confidence: 85%

The Role Played in the Improvement of the SiO2/SiC Interface by a Thin SiO2 Film Thermally Grown Prior to Oxide Film Deposition

Pitthan

Palmieri

Corrêa

et al. 2012

ECS Solid State Letters

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“…This kind of compound was already observed in the interfacial region of thermal oxides grown on crystalline SiC. 8,17,18 Concerning the O 1s region of the spectra, the predominant contribution to it is a component related to oxygen in SiO 2 (O ox ), centered at 534.5 eV in the case of Fig. 4.…”

Section: Resultsmentioning

confidence: 60%

“…1 Various explanations were already proposed to this bad performance, most of them attributing it to carbon present in the oxide, in particular at the SiO 2 /SiC interface. [5][6][7][8] Another processing problem of SiC is the low oxidation rate of this material: high temperatures and/or long oxidation times have to be used to achieve the desired oxide thickness.…”

Section: Introductionmentioning

confidence: 99%

Effects of ion irradiation in the thermal oxidation of SiC

2002

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We investigated the thermal growth of SiO 2 films on 6H-SiC ͑0001͒ samples irradiated with 170 keV Ar ϩ ions. Electronic, compositional, and structural features arisen from the irradiation process were accessed. All results are compared to those of nonirradiated substrates, revealing major differences due to ion bombardment such as the enhanced rate of oxidation, the variation of roughness of both oxide surface and SiO 2 /SiC interface, and of the stress in the formed oxide layer. Modifications on the electronic structure and crystallographic characteristics of the substrate underneath the oxide were also observed in samples in which the ion irradiation damaged layer was only partially consumed by the oxidation step. The present work evidences that a careful choice of sample preparation conditions is necessary to avoid undesired characteristics in the final SiO 2 /SiC structure and points to a way of preventing irradiation related degradation of electrical characteristics while maintaining the high oxidation rate.

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“…This interface cannot be wider than 15 nm, according to previous results [22]. In this near-interface reactive region [2,3,6,7,[11][12][13][14] carbon and/or excess silicon (from SiC not completely oxidized or from Si interstitials injected as a result of SiC oxidation) may also be present. The mobility of lattice oxygen could also be responsible for this phenomenon, but it has been ruled out [21] by previous analyses of samples oxidized in the 16 O 2 = 18 O 2 = 16 O 2 gas sequence.…”

Section: Volume 89 Number 25 P H Y S I C a L R E V I E W L E T T E Rmentioning

confidence: 66%

“…On the other hand, the properties of the SiO 2 =SiC interface lead to electrical characteristics worse than those of SiO 2 =Si, while the scatter of the available data [1] suggests poor interface control. Investigations of the thermal oxide film on SiC in its different regions have been pursued [2 -7], indicating that in the surface and bulk regions the oxide is similar to that grown on Si [4,8,9], that the interface is less abrupt [5,10], and that incompletely oxidized C or Si are found near the interface [2,3,6,7,[11][12][13][14]. However, a thorough understanding of the phenomena taking place during the thermal growth of SiO 2 on SiC is still missing.…”

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Limiting Step Involved in the Thermal Growth of Silicon Oxide Films on Silicon Carbide

et al. 2002

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Thermal growth of silicon oxide films on silicon carbide in O 2 was investigated using oxygen isotopic substitution and narrow resonance nuclear reaction profiling. This investigation was carried out in parallel with the thermal growth of silicon oxide films on Si. Results demonstrate that the limiting steps of the thermal oxide growth are different in these two semiconductors, being diffusion limited in the case of Si and reaction limited in the case of SiC. This fact renders the growth kinetics of SiO 2 on SiC very sensitive to the reactivity of the interface region, whose compositional and structural changes can affect the electrical properties of the structure. DOI: 10.1103/PhysRevLett.89.256102 PACS numbers: 81.65.Mq, 61.82.Fk, 68.35.Fx, 77.55.+f In semiconductor device applications involving high power, frequency, voltage, and/or temperature, Si use is limited by its physical properties. An example is the relative narrow band gap (1.1 eV) that prevents Si devices from operating at high temperatures. The polar crystal silicon carbide (SiC) appears to be the wide band-gap material of choice since besides the wider gap (2.9 eV for the 6H polytype) SiC has other desired properties such as high thermal conductivity, breakdown voltage, and saturated electron drift velocity. It is also the only known compound semiconductor on which SiO 2 can be grown thermally. On the other hand, the properties of the SiO 2 =SiC interface lead to electrical characteristics worse than those of SiO 2 =Si, while the scatter of the available data [1] suggests poor interface control. Investigations of the thermal oxide film on SiC in its different regions have been pursued [2 -7], indicating that in the surface and bulk regions the oxide is similar to that grown on Si [4,8,9], that the interface is less abrupt [5,10], and that incompletely oxidized C or Si are found near the interface [2,3,6,7,[11][12][13][14]. However, a thorough understanding of the phenomena taking place during the thermal growth of SiO 2 on SiC is still missing.Growth of SiO 2 on SiC is much slower than on Si, presenting more scattered data [15][16][17] and differences along the polar directions [ 0001 and (0001) in the hexagonal polytypes]. Several authors have tried to model the kinetics of the thermal growth of SiO 2 on SiC [15,17,18], mostly within the framework of the Deal and Grove model [19], which satisfactorily describes the thermal growth of SiO 2 on Si in dry O 2 for oxide thicknesses above 20 -30 nm. This model is based on a stationary flux of O 2 , the only mobile species, across the growing oxide and on reaction with Si to form SiO 2 only at an abrupt interface. These efforts were curve fittings which did not consider the reaction mechanisms and limiting steps characteristic of the SiO 2 =SiC system. The elucidation of the oxidation mechanismsidentification of the limiting steps and the mobile species and how they are transported during oxide thermal growth-is necessary to develop an oxidation model for SiC allowing prediction and control of the ...

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Initial stages of SiC oxidation investigated by ion scattering and angle-resolved x-ray photoelectron spectroscopies

Cited by 67 publications

References 17 publications

The Role Played in the Improvement of the SiO2/SiC Interface by a Thin SiO2 Film Thermally Grown Prior to Oxide Film Deposition

The Role Played in the Improvement of the SiO2/SiC Interface by a Thin SiO2 Film Thermally Grown Prior to Oxide Film Deposition

Effects of ion irradiation in the thermal oxidation of SiC

Limiting Step Involved in the Thermal Growth of Silicon Oxide Films on Silicon Carbide

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