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Ultralow-k nanoporous organosilicate dielectric films imprinted with dendritic spheres

Nature Materials volume 4, pages 147–150 (2005)Cite this article

Abstract

Integrated circuits that have improved functionality and speed in a smaller package and that consume less power are desired by the microelectronics industry as well as by end users, to increase device performance and reduce costs1,2,3,4. The fabrication of high-performance integrated circuits requires the availability of materials with low or ultralow dielectric constant (low-k: k ≤ 2.5; ultralow-k: k ≤ 2.0) because such dielectrics not only lower line-to-line noise in interconnect conductors, but also minimize power dissipation by reducing the capacitance between the interconnects1,2,3,4. Here we describe the preparation of low- and ultralow-k nanoporous organosilicate dielectrics from blends of polymethylsilsesquioxane (PMSSQ) precursor with globular ethyl acrylate-terminated polypropylenimine dendrimers, which act as porogens. These dendrimers are found to mix well with the PMSSQ precursor and after their sacrificial thermal decompositions result in closed, spherical pores of <2.0 nm radius with a very narrow distribution even at high loading. This pore size and distribution are the smallest and the narrowest respectively ever achieved in porous spin-on dielectrics. The method therefore successfully delivers low- and ultralow-k PMSSQ dielectric films that should prove very useful in advanced integrated circuits.

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Figure 1: Procedure for preparation of a nanoporous organosilicate dielectric thin film.
Figure 2: GISAXS of a nanoporous PMSSQ thin film deposited onto a silicon substrate.
Figure 3: GISAXS profiles and pore size distribution.

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Acknowledgements

This study was supported by the Center for Integrated Molecular Systems (KOSEF) and by the Ministry of Education (BK21 Program). Synchrotron GISAXS and XR measurements were supported by the Ministry of Science and Technology and the POSCO.

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  1. Byeongdu Lee and Young-Hee Park: These authors contributed equally to this work

Authors and Affiliations

  1. Department of Chemistry, and Division of Molecular and Life Sciences, Center for Integrated Molecular Systems, Pohang Accelerator Laboratory, Polymer Research Institute, Pohang University of Science and Technology, Pohang, 790-784, Republic of Korea

    Byeongdu Lee, Young-Hee Park, Yong-Taek Hwang, Weontae Oh, Jinhwan Yoon & Moonhor Ree

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  1. Byeongdu Lee
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Correspondence to Moonhor Ree.

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Lee, B., Park, YH., Hwang, YT. et al. Ultralow-k nanoporous organosilicate dielectric films imprinted with dendritic spheres. Nature Mater 4, 147–150 (2005). https://doi.org/10.1038/nmat1291

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