| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 95 === Using two metal elements, iron and tin, to prepare catalyst and combine chemical vapor deposition (CVD) process can grow carbon coils successfully. There are tow methods to prepare catalyst. One is to mix iron acetate with tin acetate, and use alcohol as solvent to dissolve these two powders. Such a catalyst is called solution catalyst. The other method is to coat iron film and tin film on wafer by e-beam evaporator directly. This catalyst is named thin film catalyst. Coils grown by solution catalyst have coil diameter 100 nm~1100 nm, fiber diameter 100 nm~300 nm, and pitch 100 nm~1400 nm; While by thin film catalyst have coil diameter <600 nm, fiber diameter <200 nm, pitch <800 nm. Results have been observed by SEM and TEM. Iron is the key to grow carbon tubes. Tin makes carbon tubes become spiral shape. Advantages of tow-element growth of carbon coils are that the process is more convenient and it’s easy to analyze the growth model of carbon coils. It has been researched thickness of catalyst is a key point to effect average coil size and it’s range. Using solution catalyst can grow carbon coils which have larger size.
Another part of this research is to make small patterns by micro electron mechanics (MEMs) process and let carbon coils grow inside the pattern. Single carbon coil whose length is above 10 μm can be got in the patterned area. This research can help assaying and locating carbon coils.
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