A Photoresist Passivated Carbon Nanotubes Field Effect Transistor for Recognition of Ion Concentration

• Main Author: 蕭程允
• Other Authors: 楊裕雄
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/91669435132325569199

碩士 === 國立交通大學 === 生物科技系所 === 93 === A carbon nanotube field effect transistor (CNT FET) was designed, and fabricated, in this study where the characteristic of the device was examined in aqueous solution with distinct ionic strength. Carbon nanotubes, acting the channels of the FET, bridging across two Ti pad (source and drain) to form the CNT FET. We measured the leakage current in the devices with photoresist passivated and non-passivated under adding a liquid-gate. The passivated layer, formed over the source/drain electrode, greatly suppressed the gate leakage current by two to three orders of magnitude. The currents through the CNTs were noticeably different between two liquid samples: deionizeded water and aqueous solution (NaCl). Furthermore, the current obtained in aqueous solution with various concentration of NaCl (1x10-6∼1M) was evaluated. The results demonstrated that the passivated CNT FET was capable of determining the ionic concentration of aqueous solution under an additional voltage for inducing the separation of charges. It also implied that the CNT FET can be applied to detect the ions produced from specifically designed biological reactions. It is expected that the CNT FET can be designed into a highly sensitive bio-sensor.