CNTCONTACT · Doped semiconductor contacts for low resistance contacts to carbon nanotubes

Carbon nanotubes (CNTs) are attracting an immense research effort due to their remarkable electronic properties. The ability to integrate CNTs into applications such as sensors and low power transistors will allow the technology to fully benefit from these structures. The advantages CNTs offer include high sensitivity, very low power requirements, and the ability to use nanometer scale components. Key issues remain before the full potential of CNTs can be exploited: Low resistivity contacts must become available, CNTs must interface with high-k dielectrics, and we must understand their transport properties thoroughly. This project will address all three of these challenges. Further challenges related to growth and processing control are addressed by numerous researchers in the field.The primary goal of this project is to establish effective contacts to semiconducting CNTs. Interfacing CNTs with doped semiconductors such as Al:ZnO is proposed. An important side goal of the project is to develop a self consistent physical model to explain charge transport in CNTs, and to account for defects, transport barriers, and nonidealities at the CNT/contact interface. Such a model is also useful in calculating detailed band diagrams of the structures under study, which will help advanced device design.The doped semiconductor, Al:ZnO, will be deposited on top of CNTs using atomic layer deposition. This method offers a high level of conformal coating, and it is expected to yield low defect density conducting films. Detailed structural and electrical characerization using CNT field effect transistors as prototype devices will be carried out, providing data on the effects of pre- and post-deposition processing. Transport characteristics will be extracted from the characterization, and will be used in future iterations of the contacts. Low contact resistance and a thorough understanding of the transport properties are the expected outcomes of the project.""