Wavelength selective materials modification of bulk As2S3 and As2Se3 by free electron laser irradiation

Hari, Parameswar; Cheney, C. Parks; Luepke, Gunter; Singh, Sankalp Kumar; Tolk, N. H.; Sanghera, J.S.; Aggarwal, Ishwar D.

doi:10.1016/s0022-3093(00)00072-7

Cited by 21 publications

(15 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Finally, we refer to a pioneering work for As 2 S(Se) 3 by Hari et al (2000). They report that, upon pulsed irradiation of infrared light with photon energies of ~0.4 eV (< E g /2), vibrational absorptions of impurities such as C-H x are *A recent calculation suggests that As atoms with sp 2 electron configuration also produce tail states (unpublished).…”

Section: Low-energy (Sub-gap Mid-gap Vibrational) Excitationmentioning

confidence: 99%

Photo-induced phenomena in chalcogenide glasses

Tanaka

2014

Chalcogenide Glasses

View full text Add to dashboard Cite

Section: Low-energy (Sub-gap Mid-gap Vibrational) Excitationmentioning

confidence: 99%

Photo-induced phenomena in chalcogenide glasses

Tanaka

2014

Chalcogenide Glasses

View full text Add to dashboard Cite

“…We believed that this layer was composed of the oxides of As 2 O 3 and SO 2 , because that the O 2 plasma is well known to be very effective to oxidize the surface of many solid materials, including GaAs, 13 Al, 14 and Si, 15 etc., and it is also know that the surfaces of solid As and S can even spontaneously oxidize in air. 16 The low etch rate ͑20 nm/ min͒ of pure Ar plasma for sample 2 in Table I was generated by a pure physical sputtering effect of the plasma. Ar is an inert gas, having no chemical etching effect, but Ar ions are much heavier than O ions, they can remove material via physical sputtering effect.…”

Section: B Etch Rate and Selectivitymentioning

confidence: 99%

Dry-etch of As2S3 thin films for optical waveguide fabrication

Ruan

Luther‐Davies

et al. 2005

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

Plasma etching to As 2 S 3 thin films for optical waveguide fabrication has been studied using a helicon plasma etcher. The etching effects using the processing gases or gas mixtures of O 2 , Ar, and CF 4 were compared. It was found that the O 2 plasma had no chemical etching effect to the As 2 S 3 , but it could oxidize the surface of the As 2 S 3. The Ar plasma provided a strong ion sputtering effect to the films. The CF 4 plasma exhibited a too strong chemical etch to the As 2 S 3 , leading to serious undercutting and very rough sidewalls of the waveguides. Ar and O 2 gases were compared as the additives to dilute the CF 4 processing gas. The etch rate of the As 2 S 3 was reduced dramatically from over 2000 nm/ min to a few hundred nm/min when the pure CF 4 gas was heavily diluted with 70% Ar or O 2 gas. The undercutting and sidewall roughness of the etched waveguides were also decreased greatly when above dilution was made, which was associated with an enormous weakening of the isotropic chemical etch induced by neutral reactants in the plasma. In addition, the O 2 showed a better dilution effect than the Ar in reducing the etch rate of the As 2 S 3 ; and the O 2 /CF 4 plasma also enabled a much lower erosion rate to Al mask layers than the Ar/ CF 4 plasma at similar plasma conditions. The As 2 S 3 waveguides with near vertical and very smooth sidewalls were obtained using an optimized O 2 /CF 4 plasma. Moreover, the etching behaviors and mechanisms were explained base on the etching results, and on the characteristics of the applied plasma diagnosed using Langmuir probe and optical spectroscopy techniques.

show abstract

“…This fact manifests the high stability of As 2 S 3 -based bulk glasses towards thermal and visible light-irradiation treatments. However, a recent study of bulk As 2 S 3 glass has shown that wavelength-selective infrared irradiation can cause a significant reduction of the intensity of vibrational modes associated with CH x impurities [21]. Thus, the method of wavelength-selective infrared irradiation may provide a novel non-thermal treatment for the reduction of infrared absorption attributed to impurities in As 2 S 3 -based glasses.…”

Section: Mid Infrared Transmittancementioning

confidence: 99%

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

et al. 2002

View full text Add to dashboard Cite

The effect of rare earth (Dy and Sm) and transition metal (Mn) luminescent impurities on the optical properties of As 2 S 3 glass is studied in a wide spectral region. The Raman, infrared, band-to-band and edge absorption spectroscopies are employed to obtain information about the incorporation of impurity ions in the host glass structure and the corresponding changes in intrinsic optical characteristics. The effects of light-soaking and thermal treatment on the doped As 2 S 3 glasses were examined as well. In the fundamental absorption region a reflectivity maximum at 2.98 eV shows blue (Dy, Sm) or red (Mn) shift depending on the electronegativity of the impurity, in accordance with the corresponding variations of the glass structure. Near the edge absorption the impurity affects strongly the slope and the magnitude of the weak absorption tail. In the wide range of transparency the addition of impurity suppresses several absorption bands indicating the interaction of dopants with the host glass contaminations. Some variations of the characteristic Raman spectra under light exposure and thermal ageing of doped glasses were registered. The observed effects of metal dopants on the As 2 S 3 glass are discussed in connection with the expected behaviour of the impurities in the glass.

show abstract

Wavelength selective materials modification of bulk As2S3 and As2Se3 by free electron laser irradiation

Cited by 21 publications

References 5 publications

Photo-induced phenomena in chalcogenide glasses

Photo-induced phenomena in chalcogenide glasses

Dry-etch of As2S3 thin films for optical waveguide fabrication

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

Contact Info

Product

Resources

About