Hyperbranched polysiloxane (HBPSi)-based polyimide films with ultralow dielectric permittivity, desirable mechanical and thermal properties
Hyperbranched polysiloxane (HBPSi)-based polyimide films with ultralow dielectric permittivity, desirable mechanical and thermal properties
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超支化聚硅氧烷 (HBPSi) 基聚酰亚胺薄膜具有超低介电常数、理想的机械和热性能
DOI：
10.1039/c5tc03391h
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发表时间：
2016-01-01
影响因子：
6.4
通讯作者：
Zhang, Qiuyu
中科院分区：
文献类型：
--
作者：
Lei, Xingfeng;Chen, Yanhui;Zhang, Qiuyu
低介电介质聚酰亚胺(PI)在下一代高密度、高速度集成电路中的需求很高。据报道，在PI中引入氟或气孔可以有效地获得低介电性，但不可避免地会恶化力学和/或热性能。因此，如何在保持力学性能和热性能的同时降低聚酰亚胺的DK对聚酰亚胺来说是一大挑战。本论文采用均苯四甲酸二酐(PMDA)和4，4‘-氧基二苯胺(Oda)与胺功能化的超支化聚硅氧烷(HBPSi)进行共聚，制备了一系列坚韧的PI薄膜。35wt%HBPSi PI薄膜具有优异的介电性能，其dk低至2.24(1 MHz)，这主要是由于体积较大的HBPSi提供了更大的自由体积和介电限制效应。35wt%HBPSi PI具有良好的热稳定性和优异的力学性能，其玻璃化转变温度为388℃，5%的失重温度高达554℃，拉伸强度为80.6 MPa，断裂伸长率为13.7%，拉伸模数为1.36 GPa.薄膜均匀平整，表面粗糙度低至0.42 nm，吸水率小于1.5%，具有良好的耐湿性。HBPSiPI突出的综合性能使其成为未来层间介质材料的有力候选者。
Low-dielectric polyimide (PI) is on high demand in the next generation of high-density and high-speed integrated circuits. The introduction of fluorine or pores into PIs has been reported to efficiently obtain low-dielectric properties, but unavoidably deteriorate the mechanical and/or thermal properties. Therefore, it is a great challenge for PI to decrease its Dk and simultaneously maintain its mechanical and thermal properties. Herein, a series of robust PI films were fabricated by copolymerizing amine-functionalized hyperbranched polysiloxane (HBPSi) with pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA). The outstanding dielectric properties were achieved in a 35 wt% HBPSi PI film, which exhibits a Dk as low as 2.24 (1 MHz), mainly owing to the enhanced free volume and dielectric confinement effect afforded by the bulky HBPSi. Meanwhile, 35 wt% HBPSi PI demonstrates remarkable thermal stability and admirable mechanical properties, with the glass transition temperature of 388 °C, 5% weight loss temperature in argon flow up to 554 °C, a tensile strength of 80.6 MPa, elongation at break of 13.7% and a tensile modulus of 1.36 GPa. It also demonstrates conspicuous film homogeneity and planarity with the surface roughness as low as 0.42 nm and good moisture resistance with water uptake less than 1.5%. The prominent comprehensive properties make HBPSi PI a strong candidate for the future interlayer dielectrics.