Three diisocyanate units having different linearity and planarity on the basis of the arrangement of constituent aromatic rings are used to synthesize three polyurethanes (PUs) and the effects of the molecular structure of the diisocyanate units on phase separated morphologies of PUs have been studied. The linear and planar diisocyanate unit allows good packing of the hard segments in the hard domain by extensive intersegmental hydrogen bonding, and it forms a well ordered, long hard domain. However, the nonlinear and noncoplanar diisocyanate unit shows a lesser degree of hydrogen bonding in the short hard domain. Strong preferential orientation of the rigid/long hard domains inside a macroscopic grain boundary has been observed with the polarizing optical microscope especially for the PU based on the rigid diisocyanate. It was concluded that the molecular structure of the diisocyanate unit in PU plays an important role in determining the interchain interaction, the detailed phase‐separated domain structure, and local domain orientation in each grain boundary. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Spin-on dielectric (SOD) is widely used in semiconductor industry, to form insulating layers including shallow trench isolation (STI) or inter-layer dielectrics (ILD). SOD has several advantages over high density plasma chemical vapor deposition (HDP-CVD) for manufacturing process, such as less defect and higher throughput. However, both SOD and HDP-CVD have a drawback, which is a high temperature curing process required to make pure silicon oxide layers.High temperature curing could cause high stress and thermal distortion. These disadvantages are becoming more problematic as the semiconductor device shrinks. To resolve the problem, we tested several additives to moderate the curing temperature. It was found out that amine compounds were effective to convert SOD polymer into silicon oxide, therefore the curing process could be performed at a lower temperature. We also observed that the SOD films containing amine additives have higher etch resistance during a wet etch process. These results, as well as the lower curing temperature, are beneficial for manufacturing insulating layers. Further investigation is ongoing to characterize other film properties of the SOD with additives, and to optimize the formulation conditions according to the requirements of manufacturing processes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.