Plasma ion assisted deposition (PIAD) was employed to prepare a dense capping layer (seal the top surface only) or shell layer (seal both the top surface and the sidewall) of an e-beam coating. The lateral water vapor diffusion was confirmed by a monolayer e-beam coating with a capping layer. The stress evolution and spectral shift of the multilayer e-beam coatings with/without capping/shell layers were comparatively studied. The protective effect of the shell layer on the e-beam coating was further investigated by water bath treatment. The experimental results proved that the PIAD shell layer can be used to address the time-dependent and environmental reliability issues of the e-beam coatings for high-power laser applications.
Plasma-enhanced atomic layer deposition (PEALD) has been widely used in microelectronics due to its precise coating thickness control and high uniformity. Coating qualities are strongly affected by deposition parameters and can be tailored accordingly. In this work, SiO2 and HfO2 monolayers were deposited by PEALD on fused silica and BK7 substrates for different measurement. The influence of deposition temperature and precursor pulse time on both coatings were studied. Coating thickness was obtained by ellipsometer and coating roughness was extracted by atomic force microscope. Laser-induced damage threshold (LIDT) and damage morphology were also studied. By optimizing the process parameters, coatings with desired properties can be deposited.
In this work, 532-nm high-reflection (HR) coatings have been deposited at different deposition temperatures by electron-beam evaporation technology. The spectral performance, e-field distribution, surface roughness, stoichiometry, as well as the laser resistance of the prepared 532-nm HR coatings are investigated. Experimental results indicate that the LIDT of the 532-nm HR coatings can be greatly influenced by deposition temperature. A relatively high deposition temperature benefits the crystallization and oxidation, and improves the LIDT of the 532-nm HR coatings. In addition, the SiO2 overcoat layer is also demonstrated to be effective in suppressing the delamination damage morphology and improving the LIDT of the 532-nm HR coatings.
The properties of coatings deposited by electron-beam (e-beam) technique can be easily influenced by environmental humidity, causing spectrum shift, residual stress evolution, and wave front errors. HfO2 / SiO2 multilayer coatings with different overcoat layer deposition parameters have been prepared. The optical spectrum shifts induced by atmosphere-vacuum effect are investigated by a spectrometer. The laser resistance is studied and their damage morphologies are characterized by a scanning electron microscope. The surface morphologies and the global mechanical stresses of the films are analyzed by an atomic force microscope and zygo interferometer, respectively. The experimental results demonstrate that by introducing a dense capping SiO2 layer employed with plasma ion assisted deposition, considerable environmental stability of e-beam coatings can be improved due to retarded water vapor transport. A relatively smaller grain size can be obtained as well. Moreover, the laser-induced damage threshold shows no significant difference.
The properties of coatings deposited by electronic beam (e-beam) technique can be easily influenced by environmental humidity, causing spectrum shift, residual stress evolution, and wave front errors. In this work, HfO2/SiO2 multilayer coatings with different overcoat layer deposition process were prepared. The optical spectrum shift caused by atmosphere-vacuum effect of the prepared samples was investigated by spectrometer. The laser-induced damage resistance was studied and the damage morphologies were characterized by Scanning Electron Microscope (SEM). The surface morphology and global coating stress of the films were analyzed by Atomic Force Microscope (AFM) and Zygo interferometer, respectively. The experimental results demonstrate that by a capping SiO2 layer employed by plasma ion assisted deposition (PIAD), considerable stability concerning the environmental stability of e-beam coatings can be improved due to delayed water vapor transport rate. A relatively smaller grain size can be obtained as well. Moreover, the laser- induced damage threshold (LIDT) shows no significant differences.