| AVS 64th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Wednesday Sessions |
| Session PS-WeA |
| Session: | Modeling of Plasmas |
| Presenter: | Satoshi Hamaguchi, Osaka University, Japan |
| Authors: | S. Hamaguchi, Osaka University, Japan K. Karahashi, Osaka University, Japan |
| Correspondent: | Click to Email |
The fast development and rapidly spreading use of Information and Communication Technologies (ICT) worldwide are firmly founded on the continuing development of semiconductor device technologies. With an increasing demand for higher integration density of large-scale integrated (LSI) circuits with lower energy consumption, device sizes continue to shrink, their structures become more complex (such as those of 3D multigate fin FETs), and unconventional materials (such as magnetic materials for MRAMs) are used for semiconductor devices. Challenges for plasma processing technologies used for LSI device fabrication therefore lie in the development of new plasma chemistry that allows processing with atomic-scale accuracy for existing as well as new materials used for crucial parts of semiconductor devices. Processing with atomic-scale accuracy is required to minimize material damages induced by ion bombardment, which means more chemistry-driven, rather than physical-sputtering driven, processes must be employed. For the development of plasma etching chemistry, the guiding principle is to find volatile molecules that can be formed from materials to be etched. However, unlike silicon or germanium based materials, which can be etched by the formation of volatile halides, most metal or metal oxides do not form volatile molecules under low-pressure plasma conditions. For example, the formation of volatile metal-organic complexes (such as metal carbonyls) from a metal or metal oxide surface is unlikely to occur in a low-pressure plasma as their coordinate covalent bonds are so weak that they could be easily broken by ion bombardment. The authors have analyzed etching chemistries of various materials, such as metal oxides, magnetic metals, amorphous carbon, as well as Si-based materials, using multi-beam experiments [1] and molecular dynamics (MD)/first-principle quantum mechanical (QM) simulations. In this work, we shall summarize our recent work on etching mechanism analyses and attempt to predict the future direction of process development.
References
[1] K. Karahashi and S. Hamaguchi, J. Phys. D: Appl. Phys. 47 (2014) 224008.