Proceedings of the Korean Vacuum Society Conference (한국진공학회:학술대회논문집)
- 2012.08a
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- Pages.254-255
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- 2012
Effects of Neutral Particle Beam on Nano-Crystalline Silicon Thin Film Deposited by Using Neutral Beam Assisted Chemical Vapor Deposition at Room Temperature
- Lee, Dong-Hyeok (Department of Display and Semiconductor Physics, Korea University) ;
- Jang, Jin-Nyoung (Department of Display and Semiconductor Physics, Korea University) ;
- So, Hyun-Wook (Department of Display and Semiconductor Physics, Korea University) ;
- Yoo, Suk-Jae (National Fusion Research Institute) ;
- Lee, Bon-Ju (National Fusion Research Institute) ;
- Hong, Mun-Pyo (Department of Display and Semiconductor Physics, Korea University)
- Published : 2012.08.20
Abstract
Interest in nano-crystalline silicon (nc-Si) thin films has been growing because of their favorable processing conditions for certain electronic devices. In particular, there has been an increase in the use of nc-Si thin films in photovoltaics for large solar cell panels and in thin film transistors for large flat panel displays. One of the most important material properties for these device applications is the macroscopic charge-carrier mobility. Hydrogenated amorphous silicon (a-Si:H) or nc-Si is a basic material in thin film transistors (TFTs). However, a-Si:H based devices have low carrier mobility and bias instability due to their metastable properties. The large number of trap sites and incomplete hydrogen passivation of a-Si:H film produce limited carrier transport. The basic electrical properties, including the carrier mobility and stability, of nc-Si TFTs might be superior to those of a-Si:H thin film. However, typical nc-Si thin films tend to have mobilities similar to a-Si films, although changes in the processing conditions can enhance the mobility. In polycrystalline silicon (poly-Si) thin films, the performance of the devices is strongly influenced by the boundaries between neighboring crystalline grains. These grain boundaries limit the conductance of macroscopic regions comprised of multiple grains. In much of the work on poly-Si thin films, it was shown that the performance of TFTs was largely determined by the number and location of the grain boundaries within the channel. Hence, efforts were made to reduce the total number of grain boundaries by increasing the average grain size. However, even a small number of grain boundaries can significantly reduce the macroscopic charge carrier mobility. The nano-crystalline or polymorphous-Si development for TFT and solar cells have been employed to compensate for disadvantage inherent to a-Si and micro-crystalline silicon (