AVS 58th Annual International Symposium and Exhibition
    Spectroscopic Ellipsometry Focus Topic Thursday Sessions
       Session EL-ThP

Paper EL-ThP4
Study of the Thin Film Growth of Volatile Condensable Material via In Situ Ellipsometry and Quartz Crystal Microbalance Measurements

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

Session: Spectroscopic Ellipsometry Poster Session
Presenter: Jinya Pu, The University of Nebraska
Authors: J. Pu, The University of Nebraska
F. Zhou, The University of Nebraska
N.J. Ianno, The University of Nebraska
Correspondent: Click to Email
DC-93-500, SCV-2590 and SCV-2590-2 silicone/siloxane based co-polymer serve as adhesive components in communications satellites and other spacecraft under adverse low-earth and geo-synchronous orbits. The outgassing and deposition of Volatile Condensable Materials (VCM’s) from these adhesives onto optically-sensitive surfaces of satellites is of significant interest to spacecraft-contamination engineers. In our work, samples of these materials are heated to 100 C in a liquid nitrogen (LN2) cooled cryo-shroud lined high vacuum chamber. One MK-18 quartz crystal microbalance (QCM) sensor is placed above the effusion cell which is mounted on the bottom of the chamber. At various QCM temperatures from 120K to 180K, we observed the formation of a thin film of volatile contaminant material on the gold coated QCM crystal. Spectroscopic ellipsometric data is simultaneously acquired from the depositing film. Generally, quartz crystal microbalance measures an areal mass density which is related to the density and the geometric thickness of the film, while in-situ spectroscopic ellipsometric can determine either thickness or refractive index for very thin film. Therefore, a reasonable assumption for the density of the film must be made in order to determine the thickness. By using these two techniques in combination, we can find the actual mass condensed at different temperatures. Our findings for the optical constants of materials condensed from different bulk compounds as a function of temperature will be presented.