Laser-Plasma Deposition of Silicon Carbonitride Films by the HMDS Vapor Gas Flow Activation after a Laser Beam Focus

V N Demin,M N Khomyakov,V O Borisov,A L Smirnov,S N Bagayev,G N Grachev

doi:10.4236/ampc.2021.117012

Abstract

A new laser-plasma deposition method has been developed for the plasma chemical deposition of hard silicon carbonitride coatings on stainless steel substrates from the hexamethyldisilazane (HMDS) Si2NH(CH3)6 vapor in a high-speed Ar and Ar + 10 vol.% He gas stream at the HMDS gas flow activation after the laser beam focus. The method allows depositing silicon carbonitride coatings at the rate of 0.4 - 1.2 μm·min-1, i.e. ~2 times higher than that at introducing HMDS in the laser beam focus zone. The properties of the prepared coatings have been studied by the methods of IR and Raman spectroscopy, atomic force microscopy, nanoindentation and X-ray diffraction (XRD) analysis. Studying the film structure with the use of XRD showed that the prepared silicon carbonitride coatings are X-ray amorphous. It has been found that the coating deposition rate and the structure of coatings depend on the process parameters: HMDS flow rate and plasma-generating gas (argon or (Ar + He). The method allows depositing SiCN films at a high speed and a hardness of 20 - 22 GPa.

Highlights

Laser plasma produced in a powerful optical pulsating discharge (POPD) in high-speed gas flows is a new form of optical discharge [1]
A new laser-plasma deposition method has been developed for the plasma chemical deposition of hard silicon carbonitride coatings on stainless steel substrates from the hexamethyldisilazane (HMDS) Si2NH(CH3)6 vapor in a high-speed Ar and Ar + 10 vol.% He gas stream at the HMDS gas flow activation after the laser beam focus
We present the results of studying the kinetic and physicochemical properties of the silicon carbonitride films synthesized from the hexamethyldisilazane (HMDS) precursor by means of activation after the laser beam focus

Summary

Introduction

Laser plasma produced in a powerful optical pulsating discharge (POPD) in high-speed gas flows is a new form of optical discharge [1]. We present the results of studying the kinetic and physicochemical properties of the silicon carbonitride films synthesized from the hexamethyldisilazane (HMDS) precursor by means of activation after the laser beam focus. The peculiarity of this plasma deposition variant is the effect of the action of argon plasma with a reduced energy due to its removal (taking out by the stream) from the laser beam focus. As a result of this interaction, the decomposition of the precursor molecule does not occur completely: only the organic component of the molecule is separated Such fragments fall on the substrate, where their further chemical transformation takes place with the inorganic coating formation. The addition of helium to a plasma-generating gas should not change the plasma parameters appreciably, since helium is introduced with a precursor after the laser beam focus, but it affects the growth kinetics and properties of coatings

Experimental Technique

Results and Discussion

Conclusions