Impact of Small Deviations in EEDF on Silane-based Plasma Chemistry

Abstract

In this work, we emphasize the importance of using a correct Electron Energy Distribution Function (EEDF) to model chemical reactions in High-Density (HD) low-pressure silane-containing plasmas. We have modeled chemical reactions in Ar-SiH4-N2O-(N2-H2-O2) Inductively Coupled Plasma Enhanced Chemical Vapor Deposition (ICPECVD) system, intended for deposition of silicon oxide and silicon nitride layers. For the modeling, we used the experimentally measured EEDF, deviating from the Maxwell-Boltzmann (MB) EEDF. We demonstrate that the use of an inappropriate (i.e. MB in our example) EEDF, only slightly deviating from the experimental (i.e. actual) distribution, could lead to significant discrepancies (1-2 orders of magnitude) between the calculated and actual radical densities.

Electrical Properties of Plasma-Deposited Silicon Oxide Clarified by Chemical Modeling

“…To calculate the reaction rate constants for the selected electron-impact reactions in Ar-SiH 4 -N 2 O-(H 2 -N 2 -O 2 ) plasma system at 1-6 Pa, we used the reaction cross-sections from literature (see (7) for the reactions and references) and the EEDFs obtained by LP for pure-Ar plasmas at corresponding pressures. The corresponding n e was corrected accordingly to the initial plasma composition and the pressure (see Fig.…”

“…2A). Combining the calculated (electron-impact reactions) and obtained from the literature (homogeneous reactions) reaction rate constants (see (7) for details), we simulated concentrations of 43 reactive species in plasma such as SiH x radicals and SiH x + (x=0-3) ions, polysilanes, SiO, SiN, SiH 3 O, SiH 2 O, HSiO, etc., as well as atomic hydrogen, nitrogen and oxygen.…”

Analysis of Electron Transport Coefficients in SiH4 Gas Using Boltzmann Equation in the Presence of Applied Electric Field

“…Monosilane, silane (SiH 4 ) gas is a colorless, extremely flammable, pyrophoric in air , very toxic gas and it is lighter than air, silanes refers to many compounds including organosilicon compound like, triethoxysilane (Yoshida et al, 2011), tetramethylsilane (TMS) and tetraethoxysilane (TEOS) (Kawaguchi et al, 2017). Silane has been widely used not only in the form of pure but also in mixtures with other gases for both in semiconductor industry and in thin film technologies , Vasenko, 1999, Yamaguchi et al, 1989, Peck, 2014, Kovalgin et al, 2009. The weakly ionized gas plasmas of different discharge types (DC, rf, microwave) in pure monosilane and mixtures with other gas ( Haq,…”

Plasma-enhanced chemical vapor deposition of silicon dioxide

“…That is why secondary homogeneous reactions were also considered. The selected reactions have been summarized in [155] (which also shows the original references), and are introduced shortly in the next sections.…”

“…Relations will be drawn between plasma composition and the expected deposition rate, and the electrical properties of the films. This chapter summarizes the work published in [154][155][156].…”