Application of Raman spectroscopy for depth-dependent evaluation of the hydrogen concentration of amorphous silicon

Maurer, Claudia; Haas, Sabine; Beyer, W.; Maier, Florian; Zastrow, U.; Hülsbeck, Markus; Breuer, U.; Rau, Uwe

doi:10.1016/j.tsf.2018.02.037

Cited by 10 publications

(11 citation statements)

References 29 publications

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“…It is ignored that H outdiffusion can generate quite different depth profiles of hydrogen concentration, depending strongly on the a-Si:H material structure (compact or void-rich material) and on the properties of the film surface and the film-substrate interface. 37,57,58 Conclusions from optical (absorption) measurements toward the annealing temperature appear only possible if the depth dependence of the hydrogen concentration (or of the optical bandgap) is measured in the annealed state. Indeed, evaluation of hydrogen outdiffusion depth profiles (for rather small H diffusion lengths) may be an alternative way to determine the H diffusion coefficient 37,58 and thus the temperature in the laser spot (see Sec.…”

Section: Relationship Between Hydrogen Diffusion Length and Photo-mentioning

confidence: 99%

Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Beyer

Andrä

Bergmann

et al. 2018

Journal of Applied Physics

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Rapid thermal annealing by, e.g., laser scanning of hydrogenated amorphous silicon (a-Si:H) films is of interest for device improvement and for development of new device structures for solar cell and large area display application. For well controlled annealing of such multilayers, precise knowledge of temperature and/or hydrogen diffusion length in the heated material is required but unavailable so far. In this study, we explore the use of deuterium (D) and hydrogen (H) interdiffusion during laser scanning (employing a continuous wave laser at 532 nm wavelength) to characterize both quantities. The evaluation of temperature from hydrogen diffusion data requires knowledge of the high temperature (T > 500 °C) deuterium-hydrogen (D-H) interdiffusion Arrhenius parameters for which, however, no experimental data exist. Using data based on recent model considerations, we find for laser scanning of single films on glass substrates a broad scale agreement with experimental temperature data obtained by measuring the silicon melting point and with calculated data using a physical model as well as published work. Since D-H interdiffusion measures hydrogen diffusion length and temperature within the silicon films by a memory effect, the method is capable of determining both quantities precisely also in multilayer structures, as is demonstrated for films underneath metal contacts. Several applications are discussed. Employing literature data of laser-induced temperature rise, laser scanning is used to measure the H diffusion coefficient at T > 500 °C in a-Si:H. The model-based high temperature hydrogen diffusion parameters are confirmed with important implications for the understanding of hydrogen diffusion in the amorphous silicon material.

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Section: Relationship Between Hydrogen Diffusion Length and Photo-mentioning

confidence: 99%

Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Beyer

Andrä

Bergmann

et al. 2018

Journal of Applied Physics

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“…The reason for the emergence of the C peak was hydrogen annealing caused new chemical bonds between graphene layer and the FINEMET ribbon, such as Si-H and Si-H 2 bond. 14 There were three main effects for the FINEMET/ graphene composite ribbons during the hydrogen annealing process: [15][16][17][18][19] the rst was to remove contaminants (PMMA, etc. ), the second was to saturate the surface metal dangling bonds, and the third was to form hydrogen bonds and Si-H bonds to increase adhesion between the FINEMET ribbon and graphene.…”

Section: Resultsmentioning

confidence: 99%

Observation of the transition state of domain wall displacement and GMI effect of FINEMET/graphene composite ribbons

Zou

Chen

et al. 2019

RSC Adv.

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“…Furthermore, the relative change in the H signal at these annealing steps was measured by Raman spectroscopy using Horiba‐Yvon LabRAM at an excitation wavelength of 532 nm. Raman spectroscopy was also used to measure the H microstructure parameter ( R H ) [ 17 ] , the short‐range order (SRO), and the medium‐range order (MRO). [ 18 ] H concentration ( C H ) was measured by Fourier transform infrared spectroscopy (FTIR) on reference a‐Si:H samples deposited on crystalline silicon wafer substrates and used for estimating the H concentration in the investigated samples deposited on glass substrates.…”

Section: Methodsmentioning

confidence: 99%

“…For both Raman and infrared spectroscopy, the relative H content in the Si–H stretching modes was measured by fitting two Gaussian peaks centered at 2000 and 2090 cm −1 to the complex Si–H stretching vibration signal. [ 17 ] Hydrogen effusion measurements were performed as reported in the literature, [ 19 ] using a heating rate of 20 °C min −1 . For secondary‐ion mass spectrometry (SIMS) measurements, a time of flight instrument (TOF.SIMS‐5.NCS, Iontof GmbH, Münster, Germany) was used.…”

Section: Methodsmentioning

confidence: 99%

Investigation of Thermal Stability Effects of Thick Hydrogenated Amorphous Silicon Precursor Layers for Liquid‐Phase Crystallized Silicon

Bosan

Beyer

Breuer

et al. 2021

Physica Status Solidi (a)

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The thermal stability of thick (≈4 μm) plasma‐grown hydrogenated amorphous silicon (a‐Si:H) layers on glass upon application of a rather rapid annealing step is investigated. Such films are of interest as precursor layers for laser liquid‐phase crystallized silicon solar cells. However, at least half‐day annealing at T ≈550 °C is considered to be necessary so far to reduce the hydrogen (H) content and thus avoid blistering and peeling during the crystallization process due to H. By varying the deposition conditions of a‐Si:H, layers of rather different thermal stability are fabricated. Changes in the surface morphology of these a‐Si:H layers are investigated using scanning electron microscopy and profilometry measurements. Hydrogen effusion, secondary‐ion mass spectrometry (SIMS) depth profiling, and Raman spectroscopy measurements are also carried out. In summary, amorphous silicon precursor layers are fabricated that can be heated within 30 min to a temperature of 550 °C without peeling and major surface morphological changes. Successful laser liquid‐phase crystallization of such material is demonstrated. The physical nature of a‐Si:H material stability/instability upon application of rapid heating is studied.

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Application of Raman spectroscopy for depth-dependent evaluation of the hydrogen concentration of amorphous silicon

Cited by 10 publications

References 29 publications

Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Temperature and hydrogen diffusion length in hydrogenated amorphous silicon films on glass while scanning with a continuous wave laser at 532 nm wavelength

Observation of the transition state of domain wall displacement and GMI effect of FINEMET/graphene composite ribbons

Investigation of Thermal Stability Effects of Thick Hydrogenated Amorphous Silicon Precursor Layers for Liquid‐Phase Crystallized Silicon

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