Nanocomposites and nanomaterials 

Study surface relief formation on As-S-Se thin films after electron-beam recording 

Revutska L.O.1, Shylenko O.I.2, Stronski A.V.3, Komanicky V.2, Bilanych V.S.4, Popovych M.V.3

1National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”. Prospect Peremohy 37, Kyiv-03056, Ukraine.
E-mail: liubov.revutska@gmail.com.

2Pavol Jozef Safarik University, Park Angelinum 9, Kosice-04001, Slovakia.

3V. Lashkaryov Institute of Semiconductor Physics of the NAS of Ukraine. 
Prospect Nauky 41, Kyiv-03680, Ukraine.

4Uzhgorod National University, Narodna Square 3, Uzhgorod-88000, Ukraine.

Chalcogenide thin films are extremely attractive due to the different applications that use their ability to obtain directly during recording surface relief [1]. Among them, As-S-Se systems deserve great attention because they are characterized by a large area of glass formation and excellent linear and nonlinear properties. These glasses are used in holographic optical elements, optical memory elements, planar waveguides, etc. [1]. The interaction of these materials with the electron beam is of interest due to diversity of physical phenomena induced in chalcogenide films. 
The aim of this study is to investigate formation of surface relief on thermal evaporated As35S50Se15 chalcogenide films after e-beam irradiation with different distances between irradiation dots and exposure doses.
Formed nanostructures with a height of approximately 2 µm were detected on As35S50Se15 films after e-beam irradiation. The cones on the surface of films have Gaussian profiles. The exposure dose G varied from 12 mC·cm-2  to 12 C·cm-2.  The dependences of the height of surface nanostructures on the dose of irradiation were analyzed. The SEM images of surface relief on As35S50Se15 films were obtained. The changing of shape and parameters of the recorded surface relief on As35S50Se15 films can be explained by the charge model [2]. Charge relaxation time, and initial and inverse doses, and size of interaction region have been determined. 
These results show that As35S50Se15 films can be used for fabrication of the optical elements. 
1.	A. V Stronski, M. Vlcek, A. Sklenar, P. E. Shepeljavi, and S. A. Kostyukevich. Application of As40S60-xSex layers for high-effciency grating production // J. Non. Cryst. Solids. - 2000. - Vol. 266–269. - P. 973–978.
2.	V. Bilanych et al. Surface pattering of Ge–As–Se thin films by electric charge accumulation // Thin Solid Films. 2016. - Vol. 616. - P. 86–94.