Application of Metal Catalyst on Liquid Crystal Display and Field Emission Display­ Effects of Metal Catalyst on the Growth of Low Temperature Poly-Si and Carbon Nanotubes

• Main Authors: Chi Wei Chao, 趙志偉
• Other Authors: Ming-Shiann Feng
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/50290107948500840761

博士 === 國立交通大學 === 材料科學與工程系 === 91 === In this study, the metal catalysts were used for the application of Low temperature poly-Si (LTPS) films and carbon nanotubes (CNTs). For fabrication process of LTPS, the metal induced crystallization of amorphous Si (a-Si) and metal induced lateral crystallization of a-Si (MIC/MILC) methods were used to fabricate the LTPS films. In this study, the effects of thickness and crystallinity of a-Si films, width of a-Si channel, feature of metal pattern and furnace annealing parameters for MILC rate were studied and a kinetic model of MIC/MILC was built. Electroless plating (EP) method was supposed to replace the conventional physical vapor deposition (PVD) during MIC/MILC process. Compared to PVD method, the EP method is easier, faster, more convenient and requires lower equipment cost. The a-Si films were crystallized by EP Ni and the crystallized Si films were analyzed by SEM, TEM and XRD. Various EP and furnace annealing parameters were used to produce high quality poly-Si films in a short period of time. The high performance poly-Si was fabricated by electroless plating Ni induced lateral crystallization of a-Si (EPILC). To enhance the performance of MILC TFT, a post annealing method was used after MILC process. Two kinds of post annealing methods were used. The first method is high temperature furnace annealing. During the high temperature annealing, the needlelike MILC poly-Si grains were recombined and the defect structure was repaired. However, high temperature furnace annealing is not suitable for glass substrates. The other method is room temperature laser annealing. This method is done in the room temperature so it is suitable for glass substrates. In this thesis, the method is called NILC-ELA method. The function of NILC-ELA method is the same as that of high temperature furnace annealing. However the growth mechanism of NILC-ELA process is different from that of conventional ELA process. In this study, the growth mechanism of NILC-ELA was discussed. The performance of poly-Si TFTs was enhanced by two kinds of recrystallization process. Field emission display (FED) is one of the flat panel displays. According to previous studies, the reliability and performance of emitter could be enhanced by the combination of carbon nanotubes and TFT. However some problems were found when synthesis process of CNT was incorporated into the TFT process on the glass substrates. CNTs synthesis needs to meet three requirements in order to apply in field emission display. (Three requirements of for application of field emission display.) These three requirements are: low temperature process (＜600 ℃), selective area growth and controllable site density. In this study, an electroless plating Ni method was introduced to make CNTs synthesis more compatible with application of field emission display. According to previous studies, to synthesize CNTs at low temperatures, the size of metal catalysts should be smaller than hundreds of nm. The sizes of Ni catalysts with various plating time range from 20nm to 150nm. The CNTs were successfully synthesized at 580 ℃ in this study. Therefore, the size and density of CNTs could both be controlled by plating time. Since these two parameters could affect the field emission properties of CNTs, it could be stated that plating time could control the field emission properties of CNTs.