On the Mechanism of Silicon Nitride Chemical Vapor Deposition from Dichlorosilane and Ammonia
| Autor: | Debasis Sengupta, James B. Adams, J. Vernon Cole, Anatoli Korkin |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Reaction mechanism
Hydrogen Renewable Energy Sustainability and the Environment Mineralogy Dichlorosilane chemistry.chemical_element Thermodynamics Chemical vapor deposition Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Reaction rate chemistry.chemical_compound chemistry Silicon nitride Elementary reaction Materials Chemistry Electrochemistry Deposition (chemistry) |
| Zdroj: | Journal of The Electrochemical Society. 146:4203-4212 |
| ISSN: | 1945-7111 0013-4651 |
| Popis: | Silicon nitride, Si 3N4, films have broad industrial applications, particularly in semiconductors and integrated circuit technology. 1 One common way for depositing the films is the reaction of dichlorosilane (DCS, SiH2Cl2) with ammonia (NH3). Optimization of the film deposition and properties often requires knowledge of gas-phase and surface reaction kinetics. The commonly used approach for deriving a mechanism and kinetics of chemical vapor deposition (CVD) is based on experimental results combined with reasonable assumptions. The reaction rate parameters of the resulting gas-phase reactions and semiempirical deposition reactions are then fit to experimental film growth rate data in reactor simulations. 2-5 Such an approach, although useful, has serious limitations due to the lack of understanding of the reaction mechanism on a molecular level. Fundamental understanding of deposition chemistry can aid in implementation of new technologies and in obtaining films of high quality with respect to their structure and properties. 6 A few kinetic models available in the literature for silicon nitride deposition 2-5,7 are based on different assumptions about the mechanism of gas-phase and surface reactions. Surface reactions have been treated by assuming various forms for the conversion of adsorbed gas-phase reactants and intermediates into the final Si 3N4 film without considering possible elementary reactions. In the model suggested by Peev et al. 3 a single power-law expression, rate 5 k [SiH2Cl2] 0.49 [NH3] 0.46 (Freundlich adsorpbtion isotherm), has been used to fit to experimental data and no gas-phase reactions are considered. Roenigk and Jensen 2 have included gas-phase decomposition of DCS into dichlorosililene and hydrogen into their kinetic models, Eq. 1, in order to explain film nonuniformities and growth rate changes across the wafer during low pressure CVD growth. The formation of aminochlorosilane (ACS, SiH2(Cl)NH2) via direct reaction of DCS with ammonia, Eq. 2, was also considered as an alternative. Under the low pressure conditions studied, inclusion of this bimolecular reaction “gives less quantitative agreement with experimental data” 2 SiH2Cl2 r SiCl2 1 H2 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|