Faculty + Staff

Dr. Daniel D. Burkey

Assistant Professor B.S.ChE. (Chemical Engineering) Lehigh University, 1998 M.S. (Chemical Engineering Practice) Massachusetts Institute of Technology, 2000 Ph.D. (Chemical Engineering) Massachusetts Institute of Technology, 2003 Contact: Phone: 617.373.2993 Email: daniel@coe.neu.edu Website: http://www1.coe.neu.edu/~daniel/cvdlab

Research Focus/Background

Research in our lab focuses on thin-film deposition and characterization, as well as surface science and modification. Our primary tool for fabricating thin films and surfaces is Chemical Vapor Deposition (CVD). CVD is an interesting and often novel way of fabricating very thin, conformal coatings on any number of substrates. This versatility makes it a powerful tool for designing thin films or tailoring surfaces for specific purposes.

In the CVD technique, a low-pressure precursor vapor is exposed to an excitation source. This can be as simple as a series of heated wires, thermally activating the precursor, or as complex as plasma excitation, where the precursor is broken down in a large electric field gradient. Whatever the activation method, the reactive species generated can recombine, forming a thin film or coating on whatever substrate is present. The nature of the thin film or coating depends highly on the deposition conditions, allowing a high degree of tunability.

We are currently exploring three different areas using CVD as an enabling technology:

Sacrificial Polymer Materials:
The demand for faster and smaller computer chips continually drives materials scientists to find new and better materials of fabrication to meet technology needs. One of the most crucial parts of any computer chip is the insulating material, or dielectric, that isolates signal lines from one another. As chips become faster and more densely packed, better insulating materials are required. One of the best insulators is air or vacuum, but as can be imagined, it is difficult to make something out of nothing! However, by incorporating air or void space into the bulk insulating material, it's dielectric properties can be improved, enabling future generations of chips. We are investigating the fabrication of these void spaces by using a sacrificial polymer created via CVD integrated into the system, which can then be removed via a post-processing step to form the void. Since CVD polymers can differ in many ways from conventional polymers, understanding the deposition and degradation of these CVD materials is essential to the overall processing scheme.

Patterned Surfaces for Biosensor Applications:
This is a collaborative effort with Prof. Al Sacco, Jr. and Prof. Katherine Ziemer. Biosensors represent a hybrid approach to sensing, bringing together the powerful specificity often found in nature with the physical interfaces that can be created in the lab. For this particular application, we are attempting to create a biosensor from a genetically modified bacteria. Prof. Sacco's group is currently working on the biological systems, while Prof. Ziemer's group works on engineering a surface that will detect the output signal from the bacteria (photons). Our group is focusing on using CVD to pattern surfaces such that we will have definable areas where bacteria will and will not grow.

Multifunctional Radiation Shielding:
This is another collaborative project with Prof. Al Sacco and the CAMMP center. One of the greatest obstacles to long-duration spaceflight is astronaut exposure to debilitating or deadly radiation. Any shielding strategy that is adopted must by necessity protect against a broad spectrum of radiations, as well as be lightweight and easy to integrate. Hybrid or composite structures, blending both crystalline materials and amorphous polymers, may offer superior astronaut protection over conventional approaches. Our contribution to this effort will be to use CVD technology to deposit high-hydrogen content polymer materials on a variety of spacecraft parts, as well as integrate the crystalline materials into the matrix.

Research Areas:

• Biocompatible Surface Modification
• Polymers for Radiation Shielding Applications
• Sacrificial Polymers via CVD
• CVD for coating applications

Publications:

"Organosilicon Thin Films Deposited from Cyclic and Acyclic Precursors using Water as and Oxidant." D. D. Burkey and K. K. Gleason, Journal of the Electrochemical Society, 151(5) F105 (2004).

"Temperature-Resolved Fourier Transform Infrared Study of Condensation Reactions and Porogen Decomposition in Hybrid Organosilicon-Porogen Films." D. D. Burkey and K. K. Gleason, Journal of Vacuum Science and Technology A, 22(1) 61 (2004).

"Mechanical Properties of Organosilicon Thin Films Deposited from Cyclic and Acyclic Precursors using Water as an Oxidant." D. D. Burkey and K. K. Gleason, Proceedings of the Materials Research Society Symposium, San Francisco, CA, April 21-25, 2003, Vol. 766, pp. E6.7.1-E6.7.6.

"Structure and Mechanical Properties of Thin Films Deposited from 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane and Water." D. D. Burkey and K. K. Gleason, Journal of Applied Physics, 93(9) 5143 (2003).

"Structure and Thermal Stability of Thin-Film Poly(alpha-methylstyrene) Deposited via Plasma-Enhanced Chemical Vapor Deposition." D. D. Burkey and K. K. Gleason, Chemical Vapor Deposition, 9(2) 65 (2003).