Nanoscale studies of electron-stimulated desorption of alkali halides

• Autorzy: Szymoński M. , Kołodziej J. , Struski P. , Such B. , Czuba P. , Piątkowski P.
• Konferencja: Surface and Thin Film Structures' 1999 (7 ; 15-18.09.1999 ; Kazimierz Dolny, Poland)
• Języki publikacji: EN

Abstrakty

EN

Electron-stimulated desorption processes of alkali halides have been studied with nanoscale resolution techniques allowing for microscopic understanding of ejection and surface modification mechanisms in those materials. Over the two recenty years, new experimental data were obtained for NaCl, KCl, and KBr nanometer thin films epitaxially grown on GaAs (001) and InSb (001) substrates. Well characterized surfaces were desorbed with 1 keV electrons of various dose and current density. The ejected species were analysed with a mass selected time-of flight spectrometer. We have measured the absolute yields for both alkali and halogen atom components of desorption as well as their translational velocity distributions as a function of the film thickness in the range from 1 to 100 nm. It was found that both the fast and the slow (thermal) components of desorption were strongly thickness dependent due to diffusion mechanisms involved in the transport of the primary excitation products from the bulk to the surface. Topographic features of the modified bulk single crystals of KCl (001) and KBr (001) were observed with an UHV non-contact atomic force microscope (NC-AMF). Rectangular holes of monolayer depth with edges oriented along the main crystallographic directions of the (001) plain were visible on the irradiated surfaces. We found that ESD of alkali halides studied in this work essentially occurred in layer-by-layer mode, except for the fact that the erosion of the consecutive layer started before the erosion of the previous one was completed. The average desortion rates were determined quantitatively from our microscopic data and they were compared with the ones obtained from thin film experiments.

• Wydawca: Institute of Electron Technology
• Czasopismo: Electron Technology
• Rocznik: 2000
• Tom: Vol. 33, No. 3
• Strony: 369--374
• Opis fizyczny: Bibliogr. 21 poz.

Twórcy

autor

Szymoński M.

autor

Kołodziej J.

autor

Struski P.

autor

Such B.

autor

Czuba P.

autor

Piątkowski P.

• Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Kraków, Poland