Description
TitleGeometric limitation of self-limiting electrospray deposition
Date Created2023
Other Date2023-01 (degree)
Extent60 pages : illustrations
DescriptionMany thin film deposition techniques exist; the techniques can be divided into physical methods (top-down approach) and chemical methods (bottom-up approach). This thesis deals with a very versatile micro/nanoscale thin film deposition technique known as Self-limiting Electrospray Deposition (SLED). SLED is one mode of Electrospray Deposition (ESD), which deposits glassy insulating materials below their transition temperature onto a conductive substrate. After some spray time, a uniform thickness-limiting coating grows in the area due to charge accumulation and evaporation, which optimizes the micropatterning process. SLED gets extensive attention compared to other micropatterning methods due to its (1) simple setup, (2) economic cost advantages, (3) single-step process, and (4) compatibility with Additive Manufacturing (AM).In this study, for micropatterning purposes, Polystyrene (PS) was diluted in Methyl Ethyl Ketone (MEK) solution to 1%PS. We employed an insulated stencil mask to design a chip with patterns. The patterns were made of rows of varying geometry, and the rows were oriented in both x and y directions. The feature sizes ranged from 15, 20, 30, 60, 120, 160, and 240 µm; the gap widths, which were a ratio with respect to the feature sizes, ranged from 9, 4, 2, 1, and 0.33. The geometric limitation of the patterns on the chip was investigated at two different substrate temperatures of self-limiting (30℃) and near-glass temperature (100℃) to show the contrasting behavior of the SLED process at the glass transition temperature. The chip was heat smoothed to minimize data scattering. A Tencor P-7 stylus profilometer was used to scan the conductive chips at different substrate temperatures to obtain the height profiles and 3D view of the patterns.
During this study, we employed a model substrate (a non-coating chip) to mathematically generate an idealized profile of the chip. Density and specificity, two parameters defined by us, were obtained using the model substrate. Matlab and Origin Pro softwares were used for analyzing and calculation purposes; to demonstrate how much PS material is arriving on the patterns and to what percentage is the resultant coating specific. Using statistics, we also defined the following terms: average density, average specificity, and standard deviation. Standard deviation helped us determine how much of the material not arriving at the substrate tends to be placed on the edges of the profile.
The results illustrated that a self-limiting temperature could successfully micropattern feature sizes as small as 15 µm with a maximum accuracy of ~76.4 %. Furthermore, our results suggested that SLED could be very beneficial for a more miniaturization design while enabling the user to fully control the final thickness and morphology of the deposited thin films.
NoteM.S.
NoteIncludes bibliographical references
Genretheses
LanguageEnglish
CollectionSchool of Graduate Studies Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.