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Title: Supercritical CO2 Extraction of Porogen Phase: An Alternative Route to Nanoporous Dielectrics

Abstract

We present a supercritical CO{sub 2} (SCCO{sub 2}) process for the preparation of nanoporous organosilicate thin films for ultra low dielectric constant materials. The porous structure was generated by SCCO{sub 2} extraction of a sacrificial poly(propylene glycol) (PPG) from a nanohybrid film, where the nanoscopic domains of PPG porogen are entrapped within the crosslinked poly(methylsilsesquioxane) (PMSSQ) matrix. As a comparison, porous structures generated by both the usual thermal decomposition (at ca. 450 C) and by a SCCO{sub 2} process for 25 wt% and 55 wt% porogen loadings were evaluated. It is found that the SCCO{sub 2} process is effective in removing the porogen phase at relatively low temperatures (< 200 C) through diffusion of the supercritical fluid into the phase-separated nanohybrids and selective extraction of the porogen phase. Pore morphologies generated from the two methods are compared from representative three-dimensional (3D) images built from small angle x-ray scattering (SAXS) data.

Authors:
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC), Menlo Park, CA
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
839790
Report Number(s):
SLAC-PUB-10846
TRN: US200516%%462
DOE Contract Number:
AC02-76SF00515
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DIELECTRIC MATERIALS; DIFFUSION; PERMITTIVITY; PYROLYSIS; SCATTERING; THIN FILMS

Citation Formats

Lubguban, J. Supercritical CO2 Extraction of Porogen Phase: An Alternative Route to Nanoporous Dielectrics. United States: N. p., 2004. Web. doi:10.2172/839790.
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Lubguban, J. Supercritical CO2 Extraction of Porogen Phase: An Alternative Route to Nanoporous Dielectrics. United States. doi:10.2172/839790.
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Lubguban, J. Thu . "Supercritical CO2 Extraction of Porogen Phase: An Alternative Route to Nanoporous Dielectrics". United States. doi:10.2172/839790. https://www.osti.gov/servlets/purl/839790.
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@article{osti_839790,
title = {Supercritical CO2 Extraction of Porogen Phase: An Alternative Route to Nanoporous Dielectrics},
author = {Lubguban, J.},
abstractNote = {We present a supercritical CO{sub 2} (SCCO{sub 2}) process for the preparation of nanoporous organosilicate thin films for ultra low dielectric constant materials. The porous structure was generated by SCCO{sub 2} extraction of a sacrificial poly(propylene glycol) (PPG) from a nanohybrid film, where the nanoscopic domains of PPG porogen are entrapped within the crosslinked poly(methylsilsesquioxane) (PMSSQ) matrix. As a comparison, porous structures generated by both the usual thermal decomposition (at ca. 450 C) and by a SCCO{sub 2} process for 25 wt% and 55 wt% porogen loadings were evaluated. It is found that the SCCO{sub 2} process is effective in removing the porogen phase at relatively low temperatures (< 200 C) through diffusion of the supercritical fluid into the phase-separated nanohybrids and selective extraction of the porogen phase. Pore morphologies generated from the two methods are compared from representative three-dimensional (3D) images built from small angle x-ray scattering (SAXS) data.},
doi = {10.2172/839790},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Nov 04 00:00:00 EST 2004},
month = {Thu Nov 04 00:00:00 EST 2004}
}
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DOI:  10.2172/839790
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