PLASMA TREATMENT AND SILICON COATING TO IMPROVE THE FIELD EMISSION PROPERTIES OF CARBON NANOTUBES

• Main Authors: Chen-Pang Huang, 黃振邦
• Other Authors: Wen-ching Shih
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/03693507327789895294

碩士 === 大同大學 === 光電工程研究所 === 96 === This research has four parts, first we use the DC sputtering apparatus to deposit catalytic metal film on Silicon substrate, and then use thermal chemical vapor deposition(CVD) for the growth of carbon nanotubes(CNTs). Then the specimen was moved into the sputtering and etching dual-use system. The field emission characteristics of CNT could be changed by the bombardment of plasma processing of different gases, the final part we change the dual-use apparatus function into a sputtering deposition system, The silicon film will be deposited onto the CNTs. The CNTs with sputtering catalyst grown by thermal CVD method with the mixed ammonia and acetylene gas can be very stable and consistent to the quality of the CNTs. Under the diode structure condition, the anode and the cathode gap of 300 μ m, the turn-on electric field of the best sample measured is about 0.33 V / μ m and reached 10 μ A/cm2 which is the turn-on current density. In sputtering and etching dual-use system, The turn-on electric field of all CNTs can be reduced 10% to 20% after the bombardment of plasma treatment of different gases. Hydrogen plasma processing can increase the defects of the CNTs; nitrogen plasma processing can increase the defects of the CNTs, removing longer prominent part of the CNTs and removing the catalytic metal on the top of the CNTs. Deposition by sputtering and etching dual-use system, we deposit different thickness of silicon film on the CNTs after plasma treatment of nitrogen gas. After depositing 7 nm silicon on treated CNTs, the lifetime can be improved to 33 hours. It is much longer compared to untreated CNTs which is 5.5 hours. We can conclude that the CNTs can be protected, and lifetime is extended effectively by the treatment process and addition of silicon thin film.