Focused Ion Beam Fabrication of Individual Carbon Nanotube Devices
- PDF / 4,156,567 Bytes
- 10 Pages / 612 x 792 pts (letter) Page_size
- 66 Downloads / 229 Views
1020-GG08-01
Focused Ion Beam Fabrication of Individual Carbon Nanotube Devices Lee Chow1, and Guangyu Chai2 1 Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL, 32816-2385 2 Apollo Technologies Inc., Orlando, FL, 32750
ABSTRACT Focused ion beam (FIB) techniques have found many applications in nanoscience and nanotechnology applications in recent years. However, not much work has been done using FIB to fabricate carbon nanotube devices. This is mainly due to the fact that carbon nanotubes are very fragile and energetic ion beam from FIB can easily damage the carbon nanotubes. Here we report the fabrication of carbon nanotube (CNT) devices, including electron field emitters, atomic force microscope tips, and nano-pores for biomedical applications. This is made possible by a unique, coaxial configuration consisting of a CNT embedded in a graphitic carbon coating, which was developed by us for FIB processing of carbon nanotubes. The CNT-based atomic force microscope tip has been demonstrated. The electron field emission from the tip and the side wall of CNT will be discussed. We will also report the fabrication of a multiwall carbon nanotube nanopore for future applications. INTRODUCTION Since its discovery [1] in 1991, carbon nanotube (CNT) attracted intense interest because of their potential applications in nanotechnology [2-6]. All these applications are due to the unique properties of CNTs, among which are, high aspect ratio, large Youngís modulus [7], chemical inertness, and excellent field emission properties [8]. There are many demonstrated and proposed applications of carbon nanotube devices. In general, we can classify them into two categories: applications that required large quantities of CNTs, and applications that only required one single CNT. Here in this paper, we will concentrate on the applications that only requires one single CNT in each device. In particular, the following three carbon nanotube devices will be considered: carbon nanotubes as electron sources for electron microscopes, carbon nanotubes as sharp probe tips for the atomic force microscope, and carbon nanotubes as nano-pore for biological applications. Focused ion beam (FIB) [9, 11] is a very versatile technique to remove or to deposit materials. Because of its ability to focus an ion beam to a spot size of a few nanometers, FIB has found numerous applications [12] in nanofabrication. The focused ion beam technology is based on liquid metal ion source and ion optics technology developed in the late ë70 and early í80. The two most important functions of an FIB system are its ability to fabricate nanometer size structures and to deposit minute amounts of materials with nanometer precision. Recently, researchers started to apply FIB techniques to CNT-related applications. The initial efforts involved applying FIB to modify and manipulate CNTs directly with Ga+ ion
beams [13-16]. However, due to the high impact momentum of Ga+, the carbon atoms are easily knocked out from their lattice locations and structu
Data Loading...
