@article{3e302a926e3246ac8f51eeea86bc2466,
title = "Supercritical CO2 extraction of porogen phase: An alternative route to nanoporous dielectrics",
abstract = "We present a supercritical CO2 (SCCO2) process for the preparation of nanoporous organosilicate thin films for ultralow dielectric constant materials. The porous structure was generated by SCCO2 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 approximately 450 °C) and by a SCCO 2 process for 25 and 55 wt% porogen loadings were evaluated. It is found that the SCCO2 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.",
author = "Lubguban, {J. A.} and S. Gangopadhyay and B. Lahlouh and T. Rajagopalan and N. Biswas and J. Sun and Huang, {D. H.} and Simon, {S. L.} and A. Mallikarjunan and Kim, {H. C.} and J. Hedstrom and W. Volksen and Miller, {R. D.} and Toney, {M. F.}",
note = "Funding Information: Professor Gangopadhyay and Professor Simon acknowledge the financial support of this work from the Semiconductor Research Corporation and from the National Science Foundation Grant No. CMS-0210230. The authors would also like to acknowledge initial support provided by the State of Texas Advanced Technology Program (ATP Grant No. 003644-0229-1999). The SAXS experiments were performed at the Advanced Photon Source at Argonne National Laboratory, which is supported by the United States Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38. Portions of this research were carried out at the Stanford Synchrotron Radiation Laboratory, a national user facility operated by Stanford University on behalf of the United States Department of Energy, Office of Basic Energy Sciences",
year = "2004",
month = nov,
doi = "10.1557/JMR.2004.0413",
language = "English",
volume = "19",
pages = "3224--3233",
journal = "Journal of Materials Research",
issn = "0884-2914",
number = "11",
}