The Dependence of ECR-CVD Processing Parameters on Deposition Uniformity of Hydrogenated Amorphous Silicon (a-Si:H) Films
| Autor: | Yong Shiang Li, I. Chen Chen, L. C. Hu, Tomi T. Li, Jeng Yang Cheng, Chien Chieh Lee |
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| Rok vydání: | 2015 |
| Předmět: |
Amorphous silicon
Materials science business.industry Mechanical Engineering Substrate (electronics) Chemical vapor deposition Electron cyclotron resonance Magnetic field chemistry.chemical_compound chemistry Mechanics of Materials Electronic engineering Optoelectronics Deposition (phase transition) General Materials Science Wafer Thin film business |
| Zdroj: | Key Engineering Materials. :92-100 |
| ISSN: | 1662-9795 |
| DOI: | 10.4028/www.scientific.net/kem.656-657.92 |
| Popis: | The uniformity improvement of high deposition rate in hydrogenated amorphous silicon (a-Si:H) film deposited by electron cyclotron resonance chemical vapor deposition (ECR-CVD) is very essential for a large substrate in PV solar industry. In order to improve the uniformity in depositing thin film in large area, the auxiliary magnetic coils were designed and installed in ECR-CVD to modify the distribution of magnetic field. In addition, the dependence of the other ECR-CVD processing parameters such as resonance position, microwave power, working pressure, and substrate temperature were investigated. The results indicated that more uniform a-Si:H film could be obtained when working pressure was decreased. By using finite element analysis, it was found that location of turbo pump would impact gas flow field and this effect would become more significant at high pressure. Increasing microwave power, increasing horizontal gradient of the magnetic field to the substrate, and forming Cusp magnetic field could enhance ECR-CVD deposition uniformity greatly. However, the plasma location and substrate temperature were not major factors affecting a-Si:H film uniformity in ECR-CVD process. Finally, the optimal and the best 3.8% in uniformity could be achieved in 150mm diameter when the ratio of magnetic field strength at wafer edge to wafer center is 215%, working pressure is 1.5 mtorr, microwave power density is 4W/cm2, and substrate temperature is 180°C. |
| Databáze: | OpenAIRE |
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