| AVS 60th International Symposium and Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThA |
| Session: | Low Damage Processing |
| Presenter: | N. Watanabe, Mizuho Information & Research Inst., Japan |
| Authors: | N. Watanabe, Mizuho Information & Research Inst., Japan S. Ohtsuka, Mizuho Information & Research Inst., Japan S. Mochizuki, Mathematical Systems, Japan T. Kubota, Tohoku Univ., Japan T. Iwasaki, Mizuho Information & Research Inst., Japan Y. Iriye, Mizuho Information & Research Inst., Japan K. Ono, Mizuho Information & Research Inst., Japan S. Samukawa, Tohoku Univ., Japan |
| Correspondent: | Click to Email |
Neutral beam is an indispensable technology for fabrication of future nano-devices. Especially, a neutral beam source developed by Prof. Samukawa can achieve high neutralization efficiency, controllable energy, and realistic flux. It can perform damage-free processes and is expected to be used in mass production. To achieve production of such future devices, etching simulation is indispensable.
To construct the etching simulation by the neutral beam, simulations of (1) neutral beam generation process by collision of ions from plasma against graphite aperture wall, (2) energy and angular distributions and trajectories of ions and neutral beams passing through the aperture, (3) surface reactions such as etching and deposition, and (4) 3-dimensional etching profile evolution are needed. We performed these simulations and combined into an etching simulation.
First principles calculation was performed to simulate the neutralization process of chlorine ions. By using a larger unit cell, a planar electronic state which is located about 0.4 nm apart from the graphene sheet was found. Also, it was found that electrons emitted from chlorine particles were absorbed by the planar electronic state. It seems that the state plays an important role in a neutralization process. We have calculated neutralization efficiencies as a function of incident energy, incident angle, and number of collisions.
Based on the result, energy and angular distributions of neutral beam were calculated. In the stage of surface reaction simulation, reactions such as radical adsorption, desorption of products, beam-assisted reaction, physical sputtering, carbon adsorption, and so on were considered. Finally 3-dimensional etching simulator was developed by these results. By using the simulator we could reproduce the experimental results such as aperture aspect ratio dependence and bias dependence.
A part of this work was supported by the New Energy and Industrial Technology Development Organization (NEDO).