| Title |
Distribution of Ions and Molecules Density in N2/NH3/SiH4 Inductively Coupled Plasma with Pressure and Gas Mixture Ratio) |
| Authors |
서권상(Seo, Kwon-Sang) ; 김동현(Kim, Dong-Hyun) ; 이호준(Lee, Ho-Jun) |
| DOI |
https://doi.org/10.5370/KIEE.2017.66.2.370 |
| Keywords |
Fluid simulation ; Inductively coupled plasma ; PECVD ; Silicon nitride films |
| Abstract |
A fluid model of 2D axis-symmetry based on inductively coupled plasma (ICP) reactor using N_2/NH_3/SiH_4 gas mixture has been developed for hydrogenated silicon nitride (SiN_x:H) deposition. The model was comprised of 62 species (electron, neutral, ions, and excitation species), 218 chemical reactions, and 45 surface reactions. The pressure (10~40 mTorr) and gas mixture ratio (N_2 80~96 %, NH_3 2~10 %, SiH_4 2~10 %) were considered simulation variables and the input power fixed at 1000 W. Different distributions of electron, ions, and molecules density were observed with pressure. Although ionization rate of SiH_2{^+} is higher than SiH_3{^+} by electron direct reaction with SiH_4, the number density of SiH_3{^+} is higher than SiH_2{^+} in over 30 mTorr. Also, number density of NH^+ and NH_4{^+} dramatically increased by pressure increase because these species are dominantly generated by gas phase reactions. The change of gas mixture ratio not affected electron density and temperature. With NH_3 and SiH_4 gases ratio increased, SiH_x and NH_x (except NH^+ and NH_4{^+}) ions and molecules are linearly increased. Number density of amino-silane molecules (SiH_x(NH_2)_y) were detected higher in conditions of high SiH_x and NH_x molecules density. |