Carbon nanotube nanoelectronics and macroelectronics

Abstract

In this dissertaion, I discuss the applications of carbon nanotubes in digital integrated circuits, display electronics, and radio-frequency electronics. Despite the fact that researchers have previously demonstrated excellent field-effect transistors and integrated circuits using an individual single-walled carbon nanotube, the real challenge is to integrate those devices, minimize the device-to-device performance variation, and to make the fabrication process scalable and compatible with industry standards. To overcome these challenges, instead of using individual carbon nanotube for electronic devices, developing assembly techniques that are capable of providing thin films of highly orderd and uniformly distributed carbon nanotubes is indispensable ? ? With demonstrating scalable, practical, and high performance carbon nanotube electronics as the major objective of my PhD research, I have developed two material platforms, both of which are capable of providing high-performance nanotube transistors at complete wafer-scale. The two material platforms are horizontally aligned carbon nanotubes and thin-films of preseparated high purity semiconducting carbon nanotubes. Besides scalable material platforms, many other essential technology components, including metallic nanotube removal, increasing nanotube density, and methods to obtain air-stable n-type nanotube transistors have also been demonstrated. On the basis of the above achievements, I have further demonstrated various kinds of electronic applications including integrated circuits, display electronics, and radio-frequency electronics. ? ? The dissertation is structured as follows. First, chapter 1 gives a brief introduction to the electronic properties of carbon nanotubes, which serves as the knowledge background for the following chapters of the dissertation. In chapters 2, 3, and 4, the works related to horizontally aligned carbon nanotubes grown using chemical vapor deposition are presented. The topics include wafer-scale processing of aligned carbon nanotube electronics, improving nanotube density for better device performance, and using metal contact engineering for air-stable n-type nanotube transistors and CMOS integrated circuits. Chapters 5, 6, and 7 discuss the work related to separated nanotube thin-films, where techniques for separated nanotube thin-film assembly, fabrication of high-performance separated nanotube thin-film transistors, and applications in integrated circuits, display electronics, and radio-frequency electronics are explored. Finally, a brief summary is drawn, and some future research directions are proposed in Chapter 8. ? ? This dissertation, through experimental demonstration, proofs the potential and feasibility of using carbon nanotubes for future beyond-silicon nanoelectronics and macroelectronics. ?