Thickness measurement of a thin hetero-oxide film with an interfacial oxide layer by X-ray photoelectron spectroscopy

Kim, Kyung Joong; Lee, Seung Mi; Jang, Jong Shik; Moret, Mona P.

doi:10.1016/j.apsusc.2011.11.110

Cited by 15 publications

(14 citation statements)

References 19 publications

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“…In addition, the suboxide layer existing between the silicon substrate and the oxide film determines the SiO 2 /Si interface characteristics due to incomplete oxygen bonding. The suboxide density ( N SiO x ) present at the SiO 2 /Si interface can be calculated through eq using the ratio of the XPS silicon peak area and the suboxide peak area. − where D is the atomic density of the element, I SiO x is the suboxide peak area, and σ is the photoionization cross-sectional constant. The value of σ Si /σ SiO x was calculated as 1.1 based on the case where the photoelectron energy of the X-ray was 1487 eV.…”

Section: Resultsmentioning

confidence: 99%

Dipole Formation and Electrical Properties According to SiO₂ Layer Thickness at an Al₂O₃/SiO₂ Interface

et al. 2021

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Interfacial and electrical properties of Al 2 O 3 /SiO 2 /Si were analyzed to determine the change in interfacial defects and suboxide density according to the thickness of the SiO 2 layer and to determine the effect on dipole and flat-band voltage. As the thickness of the SiO 2 layer increased (5/7/10 nm), the density of the suboxide present at the interface (2.23/3.23/4.73 × 10 14 atoms/cm 2 ) also increased, respectively. In addition, the slow state density, fixed oxide charge density, and interface state density calculated through the capacitance−voltage (C−V) curve all differ depending on the thickness of the SiO 2 layer and are further reduced by postmetallization annealing (PMA). The flat-band voltages (V FB ) of the SiO 2 /Si sample with thicknesses of 5, 7, and 10 nm before PMA are −1.27, −1.32, and −2.20 V, respectively, and further decreased after PMA (−0.64, −0.80, and −1.74 V). Consequently, it was demonstrated that there was a difference in interfacial defects and suboxides according to the thickness. In addition, it was confirmed that when the interfacial defects and suboxides were reduced, the oxide charge state density and oxygen diffusion decreased, and thus the dipole layer strength and V FB shift decreased.

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Section: Resultsmentioning

confidence: 99%

Dipole Formation and Electrical Properties According to SiO₂ Layer Thickness at an Al₂O₃/SiO₂ Interface

et al. 2021

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“…To improve the contact properties, many strategies for surface treatments have been reported, such as ion implantation to match a work function and organic molecule/polymer binding interlayers for modulating the carrier injection mechanism, especially for field-effect transistors (FETs). ,, Compatible with low-temperature and large-area additive processing, we introduced an ultrathin end-functionalized PS interlayer between the PEDOT:PSS legs and Ag interconnects selectively. Note that 4 nm-thick grafted PS layers have been estimated from the results of X-ray spectroscopy in previous reports. ,,, A silane-terminated polymer (PS-Si(CH 3 ) 2 Cl) coupled with a sulfonate group (SO 3 – ) on a PEDOT:PSS surface provides additional paths for carrier injection. Thus, as shown in Figure a, the reduced contact resistance originating from improved charge injection can be expected after introducing a PS interlayer, which is an essential factor for maximizing the output performance of the integrated TEG modules.…”

Section: Resultsmentioning

confidence: 99%

“…Note that 4 nm-thick grafted PS layers have been estimated from the results of X-ray spectroscopy in previous reports. 40,41,45,46 A silane-terminated polymer (PS-Si(CH 3 ) 2 Cl) coupled with a sulfonate group (SO 3 − ) on a PEDOT:PSS surface provides additional paths for carrier injection. Thus, as shown in Figure 3a, the reduced contact resistance originating from improved charge injection can be expected after introducing a PS interlayer, which is an essential factor for maximizing the output performance of the integrated TEG modules.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Output Performance of All-Solution-Processed Organic Thermoelectrics: Spray Printing and Interface Engineering

Hwang

Jeong

Park

et al. 2020

ACS Appl. Mater. Interfaces

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We report two organocompatible strategies to enhance the output performance of all-solution-processed poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thermoelectric generators (TEGs): introducing an additive spray printing process and functionalized polymer interlayers to reduce the module resistance. The spray printing enabled the deposition of 1-μm-thick PEDOT:PSS layers with a high degree of design freedom, resulting in a significantly reduced sheet resistance of 16 Ω sq–1 that is closely related to the thermoelectric output performance. Also, by inserting an ultrathin silane-terminated polystyrene (PS) interlayer between the PEDOT:PSS thermoelectric layers and inkjet-printed Ag interconnects selectively, the contact resistivity extracted by the transmission line method was reduced from 6.02 × 10–2 to 2.77 × 10–2 Ω cm2. We found that the PS interlayers behaved as a thin tunneling layer, which facilitated the carrier injection from the inkjet-printed Ag electrodes into the PEDOT:PSS films by field emission with an effectively lowered energy barrier. The activation energy was also extracted using the Richardson equation, resulting in a reduction of 2.59 ± 0.04 meV after the PS treatment. Scalable plastic-compatible processability and selective interface engineering enabled to demonstrate the flexible 74-leg PEDOT:PSS TEGs exhibiting the open-circuit voltage of 9.21 mV and the output power of 2.23 nW at a temperature difference of 10 K.

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“…For the thickness measurement of ultrathin oxide films, mutual calibration method is based on the combination of a ZOM for the compensation of the offset value and a length‐unit traceable method (LTM) for the calibration of the thickness scale traceable to the SI length unit 10–13,15 …”

Section: Theory Of Mutual Calibrationmentioning

confidence: 99%

“…For the thickness measurement of ultrathin oxide films, mutual calibration method is based on the combination of a ZOM for the compensation of the offset value and a length-unit traceable method (LTM) for the calibration of the thickness scale traceable to the SI length unit. [10][11][12][13]15 F I G U R E 1 The offset c, shown as the average and standard deviation of the data in descending order of thickness. 4 F I G U R E 2 Si 2p X-ray photoelectron spectroscopy (XPS) spectra of amorphous SiO 2 films with various thickness on amorphous Si…”

Section: Theory Of Mutual Calibrationmentioning

confidence: 99%

Review on the thickness measurement of ultrathin oxide films by mutual calibration method

Kim

2021

Surface & Interface Analysis

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Mutual calibration was suggested as a method to determine the absolute thickness of ultrathin oxide films. It was motivated from the large offset values in the reported thicknesses in the Consultative Committee for Amount of Substance (CCQM) pilot study P‐38 for the thickness measurement of SiO2 films on Si(100) and Si(111) substrates in 2004. Large offset values from 0.5 to 1.0 nm were reported in the thicknesses by ellipsometry, X‐ray reflectometry (XRR), medium‐energy ion scattering spectrometry (MEIS), Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), and transmission electron microscopy (TEM). However, the offset value for the thicknesses by X‐ray photoelectron spectroscopy (XPS) was close to zero (−0.013 nm). From these results, the mutual calibration method was reported for the thickness measurement of SiO2 films on Si(100) by combination of TEM and XPS. The mutual calibration method has been applied for the thickness measurements of hetero oxide films such as Al2O3 and HfO2. Recently, the effect of surface contamination was reported to be critical to the thickness measurement of HfO2 films by XPS. On the other hand, MEIS was proved to be a powerful zero offset method which is not affected by the surface contamination. As a result, the reference thicknesses in the CCQM pilot study P‐190 for the thickness measurement of HfO2 films on Si(100) substrate were determined by mutual calibration method from the average XRR data and MEIS analysis. Conclusively, the thicknesses of ultrathin oxide films can be traceably certified by mutual calibration method and most thickness measurement methods can be calibrated from the certified thicknesses.

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Thickness measurement of a thin hetero-oxide film with an interfacial oxide layer by X-ray photoelectron spectroscopy

Cited by 15 publications

References 19 publications

Dipole Formation and Electrical Properties According to SiO₂ Layer Thickness at an Al₂O₃/SiO₂ Interface

Dipole Formation and Electrical Properties According to SiO₂ Layer Thickness at an Al₂O₃/SiO₂ Interface

Enhanced Output Performance of All-Solution-Processed Organic Thermoelectrics: Spray Printing and Interface Engineering

Review on the thickness measurement of ultrathin oxide films by mutual calibration method

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Thickness measurement of a thin hetero-oxide film with an interfacial oxide layer by X-ray photoelectron spectroscopy

Cited by 15 publications

References 19 publications

Dipole Formation and Electrical Properties According to SiO2 Layer Thickness at an Al2O3/SiO2 Interface

Dipole Formation and Electrical Properties According to SiO2 Layer Thickness at an Al2O3/SiO2 Interface

Enhanced Output Performance of All-Solution-Processed Organic Thermoelectrics: Spray Printing and Interface Engineering

Review on the thickness measurement of ultrathin oxide films by mutual calibration method

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Product

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Dipole Formation and Electrical Properties According to SiO₂ Layer Thickness at an Al₂O₃/SiO₂ Interface

Dipole Formation and Electrical Properties According to SiO₂ Layer Thickness at an Al₂O₃/SiO₂ Interface