Relief structures of crossed superimposed diffraction gratings formed in As2S3 films
Închide
Articolul precedent
Articolul urmator
571 7
Ultima descărcare din IBN:
2020-08-05 08:43
SM ISO690:2012
SERGEEV, Sergei, YOVU, M., BRANISTE, Tudor. Relief structures of crossed superimposed diffraction gratings formed in As2S3 films. In: Materials Science and Condensed Matter Physics, Ed. 7, 16-19 septembrie 2014, Chișinău. Chișinău, Republica Moldova: Institutul de Fizică Aplicată, 2014, Editia 7, p. 236.
EXPORT metadate:
Google Scholar
Crossref
CERIF

DataCite
Dublin Core
Materials Science and Condensed Matter Physics
Editia 7, 2014
Conferința "Materials Science and Condensed Matter Physics"
7, Chișinău, Moldova, 16-19 septembrie 2014

Relief structures of crossed superimposed diffraction gratings formed in As2S3 films


Pag. 236-236

Sergeev Sergei1, Yovu M.1, Braniste Tudor2
 
1 Institute of Applied Physics, Academy of Sciences of Moldova,
2 National Center for Materials Study and Testing, Technical University of Moldova
 
 
Disponibil în IBN: 11 martie 2019


Rezumat

Thin films of chalcogenide glasses are widely used as inorganic registration medium both for optical and electron beam recording due to their convenient optical and chemical properties. The amorphous films of arsenic sulfide (As2S3) exhibit high resolution of recording and possess required registration features for recording of complex patterns. The relief structures of circular symmetry, composed of N superimposed crossed diffraction gratings were formed in As2S3 thin films by ebeam recrding and following chemical etching.. Thin films of As2S3 of thickness about d=1.4 μm were prepared by thermally evaporation in vacuum on glass substrates. The underlying semitransparent electrode was used for charge leakage. E-beam recording of grating structures was performed with the aim of scanning electron microscope BS 300 (Tesla). All gratings had the same grating period value of 2 μm. Each grating of complex structure was recorded after corresponding rotation of sample. Angle of rotation determined the mutual orientation of gratings and assured the preparing the final grating structure with circle symmetry. Its value ranged from 18º to 90º, and depended on number of superimposed gratings (N) witch was varied from 2 to 10. The surface relief grating structures were formed by chemical etching in KOH water solution. The surfaces of relief structures were studied in atomic force microscope (AFM). For number of superimposed gratings ranged from 4 to 6 the mosaic surface structures with fragments of circle symmetry were clearly observed. For example the AFM image of surface relief structure composed of N=6 superimposed gratings is presented in Fig. 1. A set of equal dot rings can be seen. It seems that such structure is similar to the structure of 2D quasicrystal. Diffraction properties of superimposed gratings were studied in transmission mode at normal incidence of He-Ne laser beam ( =0.633 μm). The group of crossed gratings generated a multi-beam light diffraction, which was imaged on the screen as set of light spots arranged uniformly along circles. The set of brightest light spots in diffraction pattern corresponded to the first order light diffraction. Note that clearly observed typical diffraction pattern was generated by surface relief structure composed of number of superimposed gratings as much as N=10. It demonstrates the possibility of e-beam patterning with high recording density in amorphous As2S3 films. The first order diffraction efficiency (DE) of superimposed gratings was measured. Its value depended on dose of irradiation and decreased with N. For N>4 decreasing of DE with N was relatively weak. For produced relief structures the diffraction efficiency of each superimposed grating decreased from 3% (N=4) to 1% (N=10). It is evident that conditions of e-beam recording and following chemical etching must be specially optimized for each number of superimposed gratings.