Mediated Patterning of Sol -Gel Thin Layers: Shrinkage, Decohesion, and Lift-Off
Mikalsen, Erik Arthur
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/82738
Description
Title
Mediated Patterning of Sol -Gel Thin Layers: Shrinkage, Decohesion, and Lift-Off
Author(s)
Mikalsen, Erik Arthur
Issue Date
2003
Doctoral Committee Chair(s)
Payne, David A.
Department of Study
Materials Science and Engineering
Discipline
Materials Science and Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Engineering, Materials Science
Language
eng
Abstract
The shrinkage and densification of sol-gel layers were determined by in-situ and ex-situ measurements, where a ∼30% decrease in thickness (t) was typical during drying of sol-gel layers (T < 300°C). Constrained shrinkage, resulting from adhesion to the supporting silicon substrate, led to a coherent (crack-free) film with biaxial stresses of ∼200 MPa (t ∼ 50 nm). For ODTS-mediated sol-gel films, however, precise in-situ wafer curvature measurements determined that film stresses never exceeded 75 MPa. Additionally, interfacial adhesive strength between the substrate and the sol-gel film were evaluated for the first time using a unique pulsed-laser stress-wave technique. An adhesive strength threshold of 15 MPa was determined for sol-gel films on ODTS-functionalized silicon, whereas, the threshold strength of films deposited on unmodified silicon was determined as >25 MPa and greater than the fracture strength of silicon. In this work, hydrophobic surface regions, facilitated by directed mu-CP of a molecular film, affected adhesion so as to reduce the substrate constraint and promote de-cohesion of the sol-gel film on the sub-micron scale. That is, selective de-cohesion and lift-off were enabled by the control of local mechanical interfacial constraints.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
