Postpolymerization of Functional Organosiloxanes: An Efficient Strategy for Preparation of Low‑k Material with Enhanced Thermostability and Mechanical Properties
journal contributionposted on 23.09.2014, 00:00 by Chao Yuan, Jiajia Wang, Kaikai Jin, Shen Diao, Jing Sun, Jiawei Tong, Qiang Fang
A novel functional oligomer (Si-TFVE) with a siloxane backbone and thermally cross-linkable trifluorovinyl ether groups (−OCFCF2) is reported here. When postpolymerized at high temperature, Si-TFVE converts to an amorphous cross-linked network (Si-PFCB), which shows a dielectric constant of 2.33 and dielectric loss below 2.1 × 10–3 at 30 MHz. Si-PFCB also shows excellent film uniformity with the surface roughness less than 5.79 nm over a 1 μm square area. Moreover, Si-PFCB shows high thermostability with a 5 wt % loss temperature of 472 °C and no obvious Tg below 350 °C. In regard to the mechanical properties, Si-PFCB has Young’s modulus, hardness, and bonding strength with silicon wafer surface of 10.06 GPa, 0.392, and 4.93 GPa, respectively. These results suggest that such oligomer is suitable for utilization in ultralarge scale integration circuits. In addition, this contribution provides a new route to prepare cross-linked organosiloxanes only by heating instead of using catalysts or initiators in the traditional procedures.
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postpolymerizedMechanical PropertiesA novelutilizationEnhanced Thermostability4.93 GPasilicon wafer surface1 μ m square areadielectric lossOCFmodulu2.33MaterialPostpolymerizationwtconvertheating5.79 nmthermostabilityYoungether30 MHzfilm uniformitysiloxane backboneregardPreparationhardnessEfficient Strategyproceduresurface roughnesstrifluorovinylultralarge scale integration circuitsorganosiloxaneTg2.1strengtholigomer10.06 GPaFunctional Organosiloxanescontributioninitiatorcatalyst