Performance enhancement of excimer laser crystallized poly-Si thin film transistors with fluorine implantation technology

• Published in: Thin solid films 2008-03, Vol.516 (10), p.3128-3132
• Main Authors: Tu, Chun-Hao, Chang, Ting-Chang, Liu, Po-Tsun, Yang, Che-Yu, Feng, Li-Wei, Wu, Yung-Chun, Sze, Simon M., Chang, Chun-Yen
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Doping and impurity implantation in other materials; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronics; Elemental semiconductors; Exact sciences and technology; Excimer laser crystallization; Fluorine; Physics; Poly-Si TFTs; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Structure of solids and liquids; crystallography; Transistors
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2007.08.038

Polycrystalline silicon thin film transistors (poly-Si TFTs) with the ion implantation of fluorine elements were investigated in this study. The electrical performance and reliability were reported comprehensively. Experimental work has shown the electrical characteristics of excimer laser crystallized F-ions-implanted poly-Si TFTs are improved effectively, especially for field effect mobility. It is also found that the fluorine piled up at the poly-Si interface during thermal annealing, for the TFT fabricated without a prior deposition of pad oxide. The stronger Si–F bonds replace the Si–Si/Si–H, leading to the superior electrical reliability. However, the dose of F ions is critical in poly-Si, or the electrical characteristics of TFT devices will be degraded.