AVS 60th International Symposium and Exhibition
    Thin Film Thursday Sessions
       Session TF+PS-ThM

Paper TF+PS-ThM9
Silica Structures by Plasma-enhanced Chemical Vapor Infiltration of a Carbon Nanotube Template

Thursday, October 31, 2013, 10:40 am, Room 102 C

Session: Advanced CVD Methods
Presenter: J.M. Lund, Brigham Young University
Authors: J.M. Lund, Brigham Young University
B.D. Jensen, Brigham Young University
R.C. Davis, Brigham Young University
R.R. Vanfleet, Brigham Young University
Correspondent: Click to Email
This work investigates the advantages of infiltrating carbon nanotube structures with silica by plasma-enhanced chemical vapor deposition (PECVD). Carbon nanotube (CNT) forests have unique porous structures created through CNT interaction during the growth process. It is possible to coat individual nanotubes with silicon oxide using a PECVD process. Oxidation of the carbon nanotubes then removes the initial CNT template, resulting in a uniquely structured silica material. One application of this work is the fabrication of ultra-low thermal conductivity films. Measurements indicate a thermal conductivity less than 0.05 W/m-K. However, with this particular process the coating is invariably thicker near the top surface and the silica typically penetrates no more than 17 µm into the CNT forest. The current challenge in this work is to keep the structures as porous as possible while coating enough at the base to keep the structure continuous and attached to the substrate. Some investigation is made into the parameters influencing, and possible uses of, the infiltration depth. This includes the usefulness in capping or sealing porous structures so they can be planarized in preparation for other films and structures.