Improvement of Crystal Quality of AlN Films with Different Polarities by Annealing at High Temperature

High-quality AlN film is a key factor affecting the performance of deep-ultraviolet optoelectronic devices. In this work, high-temperature annealing technology in a nitrogen atmosphere was used to improve the quality of AlN films with different polarities grown by magnetron sputtering. After annealing at 1400–1650 °C, the crystal quality of the AlN films was improved. However, there was a gap between the quality of non-polar and polar films. In addition, compared with the semi-polar film, the quality of the non-polar film was more easily improved by annealing. The anisotropy of both the semi-polar and non-polar films decreased with increasing annealing temperature. The results of Raman spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy revealed that the annihilation of impurities and grain boundaries during the annealing process were responsible for the improvement of crystal quality and the differences between the films with different polarities.

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Annealing Time Dependence on 1.5μm Photoluminescence of Laser-Ablated β-FeSi2

MRS Proceedings ◽

10.1557/proc-0891-ee03-24 ◽

2005 ◽

Vol 891 ◽

Author(s):

Shin-ichiro Uekusa ◽

Kunitoshi Aoki ◽

Mohammad Zakir Hossain ◽

Tomohiro Fukuda ◽

Noboru Miura

Keyword(s):

Thin Films ◽

High Temperature ◽

Thermal Diffusion ◽

Annealing Time ◽

Crystal Quality ◽

Photoluminescence Intensity ◽

X Ray Diffraction ◽

X Ray ◽

Long Time

ABSTRACTWe prepared β-FeSi2 thin-films by using a Pulsed Laser Deposition (PLD) method and succeeded to observe photoluminescence (PL) around 1.5 μm corresponding to β-FeSi2 band from the long-time and high-temperature annealed β-FeSi2 thin-films. The β-FeSi2 thin-films were ablated on Si(111) substrates heated at 550°C. After ablation, long-time and high-temperature thermal annealing was performed in order to improve the crystal-quality. Annealing times were 5, 10, 20 and 40 hrs, and annealing temperature was kept at 900 °C. Crystallinity was evaluated by an X-ray diffraction (XRD) measurement. We have observed eminent improvement on crystal-quality of β-FeSi2 thin-films. Annealed samples show (220) or (202) X-ray diffraction signals of β-FeSi2 and the full width at half maximum (FWHM) of these peaks were 0.27° although the thickness of the samples decreased with annealing time. Thermal-diffusion of Si atoms was observed from substrate to thin-films. Fe atoms in the ablated thin-films also diffused into the substrate. The relationship between the thickness of β-FeSi2 thin-films and the thermal-diffusion were investigated with rutherford backscattering (RBS) measurement. Maximum photoluminescence intensity around 1.5 μm was observed from the thickest β-FeSi2 thin-film with only 5 hrs annealing.

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Investigation on the Selenization Treatment of Kesterite Cu2Mg0.2Zn0.8Sn(S,Se)4 Films for Solar Cell

Nanomaterials ◽

10.3390/nano9070946 ◽

2019 ◽

Vol 9 (7) ◽

pp. 946 ◽

Cited By ~ 4

Author(s):

Dongyue Jiang ◽

Yu Zhang ◽

Yingrui Sui ◽

Wenjie He ◽

Zhanwu Wang ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Sol Gel ◽

Crystal Quality ◽

Crystalline Quality ◽

Soda Lime Glass ◽

Soda Lime Glass Substrate ◽

X Ray ◽

Morphological Studies ◽

Selenization Temperature

High-selenium Cu2Mg0.2Zn0.8Sn(S,Se)4 (CMZTSSe) films were prepared on a soda lime glass substrate using the sol–gel spin coating method, followed by selenization treatment. In this work, we investigated the effects of selenization temperature and selenization time on the crystal quality, and electrical and optical properties of CMZTSSe films. The study on the micro-structure by XRD, Raman, X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS) analysis showed that all CMZTSSe samples had kesterite crystalline structure. In addition, the crystalline quality of CMZTSSe is improved and larger Se takes the site of S in CMZTSSe with the increase of selenization temperature and selenization time. When increasing the selenization temperature from 500 to 530 °C and increasing the annealing time from 10 to 15 min, the morphological studies showed that the microstructures of the films were dense and void-free. When further increasing the temperature and time, the crystalline quality of the films began to deteriorate. In addition, the bandgaps of CMZTSSe are tuned from 1.06 to 0.93 eV through adjusting the selenization conditions. When CMZTSSe samples are annealed at 530 °C for 15 min under Se atmosphere, the crystal quality and optical–electrical characteristics of CMZTSSe will be optimal, and the grain size and carrier concentration reach maximums of 1.5–2.5 μm and 6.47 × 1018 cm−3.

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Growth of Semi-Polar (101¯3) AlN Film on M-Plane Sapphire with High-Temperature Nitridation by HVPE

Materials ◽

10.3390/ma14071722 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1722

Author(s):

Xu Li ◽

Jianyun Zhao ◽

Ting Liu ◽

Yong Lu ◽

Jicai Zhang

Keyword(s):

High Temperature ◽

Strong Dependence ◽

Hydride Vapor Phase Epitaxy ◽

X Ray Diffraction ◽

X Ray ◽

Aln Film ◽

Negative Role ◽

Average Size ◽

Nitridation Temperature

Aluminum nitride (AlN) films were grown on the m-plane sapphire by high-temperature hydride vapor phase epitaxy (HVPE). The effect of high-temperature nitridation on the quality of AlN film was studied. The high-temperature nitridation is favorable for the formation of semi-polar single (101¯3) orientation AlN film, the quality of which shows strong dependence on the nitridation temperature. The full width at half maximum of X-ray diffraction for (101¯3) AlN film was only 0.343° at the optimum nitridation temperature of 1300 °C. It is found that the nano-holes were formed on the surface of substrates by the decomposition of sapphire in the process of high-temperature nitridation, which is closely related to the quality improvement of AlN. At the critical nitridation temperature of 1300 °C, the average size of the nano-holes is about 70 nm, which is in favor of promoting the rapid coalescence of AlN micro-grains in the early stages. However, the size of nano-holes will be enlarged with the further increase of nitridation temperature, which begins to play a negative role in the coalescence of AlN grains. As a result, the grain size will be increased and extended to the epilayer, leading to the deterioration of the AlN film.

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X-ray diffraction analysis of kaolin M1 and M2 via the Williamson–Hall and Warren–Averbach methods

Journal of Chemical Research ◽

10.1177/1747519820984729 ◽

2021 ◽

pp. 174751982098472

Author(s):

Lalmi Khier ◽

Lakel Abdelghani ◽

Belahssen Okba ◽

Djamel Maouche ◽

Lakel Said

Keyword(s):

Grain Size ◽

High Temperature ◽

Low Temperature ◽

Diffraction Analysis ◽

Mechanical Resistance ◽

X Ray Diffraction ◽

Integral Breadth ◽

X Ray ◽

Mullite Phase

Kaolin M1 and M2 studied by X-ray diffraction focus on the mullite phase, which is the main phase present in both products. The Williamson–Hall and Warren–Averbach methods for determining the crystallite size and microstrains of integral breadth β are calculated by the FullProf program. The integral breadth ( β) is a mixture resulting from the microstrains and size effect, so this should be taken into account during the calculation. The Williamson–Hall chart determines whether the sample is affected by grain size or microstrain. It appears very clearly that the principal phase of the various sintered kaolins, mullite, is free from internal microstrains. It is the case of the mixtures fritted at low temperature (1200 °C) during 1 h and also the case of the mixtures of the type chamotte cooks with 1350 °C during very long times (several weeks). This result is very significant as it gives an element of explanation to a very significant quality of mullite: its mechanical resistance during uses at high temperature remains.

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Effects of Thermal Annealing on the Properties of Zirconium-Doped MgxZn1−XO Films Obtained through Radio-Frequency Magnetron Sputtering

Membranes ◽

10.3390/membranes11050373 ◽

2021 ◽

Vol 11 (5) ◽

pp. 373

Author(s):

Wen-Yen Lin ◽

Feng-Tsun Chien ◽

Hsien-Chin Chiu ◽

Jinn-Kong Sheu ◽

Kuang-Po Hsueh

Keyword(s):

Magnetron Sputtering ◽

Radio Frequency ◽

Photoelectron Spectroscopy ◽

Annealing Temperature ◽

Radio Frequency Magnetron ◽

Radio Frequency Magnetron Sputtering ◽

X Ray Diffraction ◽

Free Electrons ◽

X Ray ◽

Mg Content

Zirconium-doped MgxZn1−xO (Zr-doped MZO) mixed-oxide films were investigated, and the temperature sensitivity of their electric and optical properties was characterized. Zr-doped MZO films were deposited through radio-frequency magnetron sputtering using a 4-inch ZnO/MgO/ZrO2 (75/20/5 wt%) target. Hall measurement, X-ray diffraction (XRD), transmittance, and X-ray photoelectron spectroscopy (XPS) data were obtained. The lowest sheet resistance, highest mobility, and highest concentration were 1.30 × 103 Ω/sq, 4.46 cm2/Vs, and 7.28 × 1019 cm−3, respectively. The XRD spectra of the as-grown and annealed Zr-doped MZO films contained MgxZn1−xO(002) and ZrO2(200) coupled with Mg(OH)2(101) at 34.49°, 34.88°, and 38.017°, respectively. The intensity of the XRD peak near 34.88° decreased with temperature because the films that segregated Zr4+ from ZrO2(200) increased. The absorption edges of the films were at approximately 348 nm under 80% transmittance because of the Mg content. XPS revealed that the amount of Zr4+ increased with the annealing temperature. Zr is a potentially promising double donor, providing up to two extra free electrons per ion when used in place of Zn2+.

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Study of Detector-Grade CdMnTe:In Crystals Obtained by a Multi-Step Post-Growth Annealing Method

Crystals ◽

10.3390/cryst8100387 ◽

2018 ◽

Vol 8 (10) ◽

pp. 387 ◽

Cited By ~ 2

Author(s):

Pengfei Yu ◽

Yongren Chen ◽

Wei Li ◽

Wenfei Liu ◽

Bin Liu ◽

...

Keyword(s):

Annealing Temperature ◽

Crystal Quality ◽

High Resistivity ◽

Detector Performance ◽

Rocking Curve ◽

X Ray ◽

Annealing Step ◽

Subsequent Step ◽

Te Inclusions ◽

Annealing Method

A multi-step annealing method was successfully applied to inclusions reduction and resistivity improvement of CdMnTe:In (CMT:In) single crystals with high resistivity, including a Cd atmosphere annealing step followed by a Te atmosphere annealing step. After the Cd atmosphere annealing step, the density of Te inclusions was reduced distinctly, and it could be also decreased in the subsequent step of re-annealing under Te atmosphere. Both the resistivity and IR transmittance decreased notably after Cd atmosphere annealing, whereas they increased tremendously after re-annealing under a Te atmosphere. The reduction of full-width at-half-maximum (FWHM) and the increase of the intensity of the X-ray rocking curve indicated an improvement of the crystal quality. Meanwhile, after Cd atmosphere annealing, the increase of the intensity of the (D0,X) peak and the disappearance of the (A0,X) peak in photoluminescence (PL) measurements suggested further that the crystal quality was improved. The detector performance was enhanced obviously after annealing. The higher the annealing temperature, the better the performance was. The detector fabricated by CMT:In slice (Cd atmosphere annealing at 1073 K for 240 h and Te atmosphere re-annealing at 773 K for 120 h) with 9.43% energy resolution and 1.25 × 10−3 cm2/V μτ value had the best detector performance.

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Xps Analysis of the Sapphire Surface as a Function of High Temperature Vacuum Annealing

MRS Proceedings ◽

10.1557/proc-159-253 ◽

1989 ◽

Vol 159 ◽

Cited By ~ 5

Author(s):

E.D. Richmond

Keyword(s):

High Temperature ◽

Binding Energy ◽

Photoelectron Spectroscopy ◽

Vacuum Annealing ◽

Xps Analysis ◽

Chemical Changes ◽

Cleaning Procedure ◽

Sapphire Surface ◽

X Ray ◽

First Time

ABSTRACTFor the first time the (1102) surface of sapphire has been investigated by X-ray photoelectron spectroscopy to ascertain chemical changes resulting from annealing in vacuum at 1300° C and 1450° C. As received substrates had a substantial surface C contaminant. For substrates that were chemically cleaned before inserting them into the MBE system no trace of carbon is detected. A residual flourine contaminant results from the cleaning procedure and is desorbed by the vacuum annealing. Spectra of annealed substrates are compared to the unannealed chemically cleaned substrates. The annealed substrates exhibit 0.4 to 0.5 eV shift to higher binding energy of the Al peak and a 0.3 eV shift to higher binding energy of the O peak. In addition, a 2% depletion of oxygen from the surface occurs.

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Air Annealing Effect on Oxygen Vacancy Defects in Al-doped ZnO Films Grown by High-Speed Atmospheric Atomic Layer Deposition

Molecules ◽

10.3390/molecules25215043 ◽

2020 ◽

Vol 25 (21) ◽

pp. 5043

Author(s):

Chia-Hsun Hsu ◽

Xin-Peng Geng ◽

Wan-Yu Wu ◽

Ming-Jie Zhao ◽

Xiao-Ying Zhang ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Band Gap ◽

Photoelectron Spectroscopy ◽

High Speed ◽

Oxygen Vacancies ◽

Annealing Temperature ◽

Atomic Layer ◽

Zno Films ◽

X Ray ◽

Layer Deposition

In this study, aluminum-doped zinc oxide (Al:ZnO) thin films were grown by high-speed atmospheric atomic layer deposition (AALD), and the effects of air annealing on film properties are investigated. The experimental results show that the thermal annealing can significantly reduce the amount of oxygen vacancies defects as evidenced by X-ray photoelectron spectroscopy spectra due to the in-diffusion of oxygen from air to the films. As shown by X-ray diffraction, the annealing repairs the crystalline structure and releases the stress. The absorption coefficient of the films increases with the annealing temperature due to the increased density. The annealing temperature reaching 600 °C leads to relatively significant changes in grain size and band gap. From the results of band gap and Hall-effect measurements, the annealing temperature lower than 600 °C reduces the oxygen vacancies defects acting as shallow donors, while it is suspected that the annealing temperature higher than 600 °C can further remove the oxygen defects introduced mid-gap states.

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Comparative Study of ZnO Thin Films Grown on Quartz Glass and Sapphire (001) Substrates by Means of Magnetron Sputtering and High-Temperature Annealing

Applied Sciences ◽

10.3390/app9214509 ◽

2019 ◽

Vol 9 (21) ◽

pp. 4509

Author(s):

Weijia Yang ◽

Fengming Wang ◽

Zeyi Guan ◽

Pengyu He ◽

Zhihao Liu ◽

...

Keyword(s):

Thin Films ◽

High Temperature ◽

Magnetron Sputtering ◽

Comparative Study ◽

Quartz Glass ◽

Photoelectron Spectroscopy ◽

Zno Thin Films ◽

High Temperature Annealing ◽

X Ray ◽

Glass Substrates

In this work, we reported a comparative study of ZnO thin films grown on quartz glass and sapphire (001) substrates through magnetron sputtering and high-temperature annealing. Firstly, the ZnO thin films were deposited on the quartz glass and sapphire (001) substrates in the same conditions by magnetron sputtering. Afterwards, the sputtered ZnO thin films underwent an annealing process at 600 °C for 1 h in an air atmosphere to improve the quality of the films. X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectra, photoluminescence spectra, and Raman spectra were used to investigate the structural, morphological, electrical, and optical properties of the both as-received ZnO thin films. The ZnO thin films grown on the quartz glass substrates possess a full width of half maximum value of 0.271° for the (002) plane, a surface root mean square value of 0.50 nm and O vacancies/defects of 4.40% in the total XPS O 1s peak. The comparative investigation reveals that the whole properties of the ZnO thin films grown on the quartz glass substrates are comparable to those grown on the sapphire (001) substrates. Consequently, ZnO thin films with high quality grown on the quartz glass substrates can be achieved by means of magnetron sputtering and high-temperature annealing at 600 °C.

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Sub-nm-Scale Depth Profiling of Nitrogen in NO- and N2-Annealed SiO2/4H-SiC(0001) Structures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.963.226 ◽

2019 ◽

Vol 963 ◽

pp. 226-229

Author(s):

Kidist Moges ◽

Mitsuru Sometani ◽

Takuji Hosoi ◽

Takayoshi Shimura ◽

Shinsuke Harada ◽

...

Keyword(s):

Nitric Oxide ◽

High Temperature ◽

Photoelectron Spectroscopy ◽

Depth Profiling ◽

Annealing Duration ◽

Nanometer Scale ◽

Pure Nitrogen ◽

X Ray ◽

Initial Stage

We demonstrated an x-ray photoelectron spectroscopy (XPS)-based technique to reveal the detailed nitrogen profile in nitrided SiO2/4H-SiC structures with sub-nanometer-scale-resolution. In this work, nitric oxide (NO)- and pure nitrogen (N2)-annealed SiO2/4H-SiC(0001) structures were characterized. The measured results of NO-annealed samples with various annealing duration indicate that preferential nitridation just at the SiO2/SiC interfaces (~0.3 nm) proceeds in the initial stage of NO annealing and a longer duration leads to the distribution of nitrogen in the bulk SiO2 within few nanometers of the interface. The high-temperature N2 annealing was found to induce not only SiO2/SiC interface nitridation similarly to NO annealing but also SiO2 surface nitridation.

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