| AVS 61st International Symposium & Exhibition | |
| Plasma Science and Technology | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | Satoshi Hamaguchi, Osaka University, Japan |
| Authors: | S. Hamaguchi, Osaka University, Japan M. Isobe, Osaka University, Japan K. Miyake, Osaka University, Japan K. Karahashi, Osaka University, Japan M. Fukasawa, Sony Corporation, Japan K. Nagahata, Sony Corporation, Japan T. Tatsumi, Sony Corporation, Japan |
| Correspondent: | Click to Email |
For the past several years we have been working on molecular dynamics (MD) simulation on silicon dioxide (SiO2) and silicon nitride (SiN) etching by fluorocarbon (FC) or hydrofluorocarbon (HFC) ion beams such as CFx+ or CFxHy+ in order to understand surface reactions and mechanisms of selective etching processes of SiO2 and SiN by FC/HFC plasmas [1]. In our study, the sputtering yields and surface chemical compositions after etching obtained from MD simulations are compared with those obtained from beam experiments. Recently we have improved the predictive capability of our simulation code and successfully obtained sputtering yields from MD simulation that are in reasonable agreement with those observed in the corresponding beam experiments. In this presentation, we shall discuss what aspects of MD simulation techniques need to be most carefully designed in order for the simulator to reproduce realistic beam-surface interactions.
Selective etching of SiN over SiO2 or vice versa is widely used in the microelectronics industry. It has been known that, at relatively low incident energy, FC or HFC ions such as CFx+ or CFxHy+ incident upon a SiO2 or SiN surface from the plasma can etch the material surface while forming a thin polymer film on it. The thickness and chemical compositions of such a polymer film sensitively affect the etch rate (i.e., sputtering yield) of the material underneath. Therefore, for an MD simulation to represent beam-surface interactions with high accuracy, the simulation needs to correctly reproduce physical processes of polymer formation. It has been demonstrated that highly accurate carbon (C)-fluorine (F) interatomic potential models including electronegativity of F and an efficient thermostat algorithm to remove excess heat from incident ions are the key for better representation of ion-surface interactions by MD simulation.
[1] K. Miyake, T. Ito, M. Isobe, K. Karahashi, M. Fukasawa, K. Nagahata, T. Tatsumi, and S. Hamaguchi, Jpn. J. Appl. Phys. 53 03DD02 (2014).