Dielectrophoretic assembly of semiconducting single-walled carbon nanotube transistor Se-Hun KWON 1 , Young-Keun JEONG 1 , Soongeun KWON 2 , Myung-Chang KANG 1 , Hyung-Woo LEE 1 1. National Core Research Center for Hybrid Materials Solution, Pusan National University, Busan 609-735, Korea; 2. Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea Received 21 April 2010; accepted 10 September 2010 Abstract: A novel burning technique for making a semiconducting single-walled carbon nanotubes (SWNTs) transistor assembled by the dielectrophoretic force was suggested. The fabrication process consisted of two steps. First, to align and attach a bundle of SWNTs between the source and drain, the alternating (AC) voltage was applied to the electrodes. When a bundle of SWNTs was connected between two electrodes, some of metallic nanotubes and semi-conducing nanotubes existed together. The second step is to burn the metallic SWNTS by applying the voltage between two electrodes. With increasing the voltage, more current flowed through the metallic SWNTs, thus, the metallic SWNTs burnt earlier than the semiconducting one. This technique enables to obtain only semi-conducting SWNTs connection in the transistor. Through the I—V characteristic graph, the moment of metallic SWNTs burning and the characteristic of semi-conducing nanotubes were verified. Key words: single-walled carbon nanotube (SWNT); semi-conducting carbon nanotube; burning technique; dielectrophoresis 1 Introduction Carbon nanotube which has a rolled structure of a graphite sheet is made by chemical vapor deposition (CVD) or arc discharge method[1]. Single-walled carbon nanotubes (SWNTs) made by these methods have ~1.4 nm in diameter and, in the case of multi-walled carbon nanotubes (MWNTs), the diameter reaches 15−20 nm. Furthermore, carbon nanotubes (CNTs) have metallic or semi-conducting characteristics according to the structure of the chiral vectors[2]. Since 1991[3], CNTs have been used in many nanoscale applications due to their unique mechanical, electrical and chemical properties. Due to these specific characteristics, CNTs have been considered a prime candidate in numerous micro and/or nanoscale sensors and devices such as field emitted displays, fuel cells, electronic circuits and mechanical sensors[4−8]. Especially, since the most application needs to make a small size device, many researchers have studied how to move, align, and deposit carbon nanotubes on the special place. The most studies for the movement, alignment and deposition of carbon nanotubes have been done by chemical vapor deposition[1, 9]. Since this method has an advantage to grow carbon nanotubes simultaneously, it is so effective in mass producible assembly. However, this method needs very expensive facilities and it is so difficult to control CNTs’ length and to find the growth conditions. Since this process requires high temperature over 800 °C, furthermore, there is a compatibility problem in the fabrication process. Another method is to deposit carbon nanotubes manually. However, it is not easy to grip a carbon nanotube by the manipulator since carbon nanotubes are so tiny. In this work, we tried to align and attach the CNTs at the room temperature by the dielectrophoretic force. By this method, we made semiconducting SWNTs transistor. When a bundle of SWNTs is connected between two electrodes, some of metallic SWNTs and semi-conducting SWNTs exist together. To retain only SWNTs, we proposed a new technique, the burning method. Through the analysis of the characteristics, we verified that only the semiconducting SWNTs were Foundation item: Project (2010-0008-276) supported for two years by Pusan National University Research Grant, by NCRC(National Core Research Center) through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology, and by Pusan National University Research Grant, 2009. Corresponding author: Hyung-Woo LEE; Tel: +82-51-5103160; E-mail: LHW2010@pusan.ac.kr; Myung Chang KANG, E-mail: kangmc@pusan.ac.kr