新型苯并环丁烯（BCB）单体的合成及其树脂性能研究

【作者】 杨军；

【导师】 肖斐；

【作者基本信息】 复旦大学 ， 材料物理与化学， 2012， 博士

【摘要】 随着超大规模集成电路(ULSI)的迅速发展,芯片特征尺寸不断减小,器件的集成度越来越高。当特征尺寸降低到亚微米级时,由线间和层间寄生电容引起的RC延迟、串扰、功耗已经成为限制器件性能的主要因素。研究和开发出性能优异的低介电常数材料,以取代传统的SiO2介电材料是解决上述问题的有效方法。苯并环丁烯(BCB)树脂由于其优异的热、机械和介电性能,已成为高性能低介电材料的选择之一。本论文从分子结构设计出发,合成出了一系列新型苯并环丁烯(BCB)单体,并对合成单体的溶解性、固化动力学以及固化后树脂的热、机械、介电性能等进行了系统研究。具体内容包括以下几部分：1.设计并合成了三种含硅氧烷结构的BCB单体/共聚物。室温下,三者均为液态,显示出良好的加工性能。固化后,三种BCB树脂具有高热稳定性(Td5>450℃)、高玻璃化转变温度、高储能模量、低介电常数、低吸水率和良好的表面平整性。其中,含环状硅氧烷结构的BCB树脂由于其内部高度的交联结构表现出特别优异的热机械性能：室温下模量达到3.9GPa,热膨胀系数为32ppm/℃2.经酰亚胺和Heck反应两步法合成出了三种BCB封端的酰亚胺单体。室温下,三种BCB封端的酰亚胺单体可溶于绝大部分有机溶剂。经热固化后三种BCB树脂显示出良好的热稳定性(Td5>435℃)和热氧化稳定性、高玻璃化转变温度(>300℃)及高储能模量(>2GPa)。但由于酰亚胺结构的高极性,固化后树脂具有较高的介电常数和吸水率。此外,BCB单体与光敏剂混合后,可直接应用于光刻加工工艺,获得清晰图形。3.以两种不同分子量氢封端的硅氧烷为前体,经硅氢化和酰亚胺化两步反应合成出了含硅氧烷及酰亚胺结构的BCB单体。两种BCB单体具有良好的溶解性能。固化后,两种BCB树脂显示出良好的热稳定性,5%失重时的温度分别为462℃和468℃。由于非极性的单体结构,树脂的介电常数和吸水率均较低。此外,旋涂膜表现出优异的表面平整性及透光性。含有较短硅氧烷链结构的BCB树脂具有更高的玻璃化转变温度和储能模量,以及更低的热膨胀系数,表明可以通过改变硅氧烷前体结构来调节树脂模量、玻璃化转变温度等热、机械性能。更多还原

【Abstract】 With the development of the Ultra-large-scale integrated circuit (ULSI), the increasing of device density has significantly made the feature size continue to decrease. As feature size reaching beyond submicron, the resistance-capacity (RC) delay, crosstalk noise and power dissipation induced by parasitic capacitance between interconnected metal lines have largely limited the progress of integrated circuits. One of the strategies to meet this problem is replacing the traditional SiO2insulator by materials with low dielectric constant. BCB-based resins have been considered as the most promising dielectrics for the manufacturing of ULSI for their superior thermal, mechanical and electrical properties. In this research, a series of novel BCB monomers were synthesized. The properties of BCB resins were also investigated systematically. The main contents and results of this paper are listed below.1. Three kinds of BCB-functionalized monomers/copolymer were synthesized, which were liquid at room temperature, implying they have excellent processability. All the BCB resins exhibited good thermal stability, high Tg, high storage moduli, low dielectric constants, low water absorptions and well planarization. Due to the high cross-linking density, BCB resin with cyclic siloxane structure showed very good thermal and mechanical properties with a modulus of3.9GPa and a CTE of32ppm/℃.2. Three kinds of BCB-functionalized imide monomers were synthesized by imidization and Heck reaction. At room temperature, the three BCB monomers exhibited good solubility in general organic solvents. After cure, the BCB resins showed good thermal stability (Td5>435℃), high Tg(>300℃), high storage moduli (>2GPa). However, the resins exhibited high dielectric constants (>2.8at1MHz) and water absorptions for the polarity of the imide structure. Furthermore, the photosensitivity of the BCB monomers was also investigated. After photolithography, fine patterns were obtained with a high resolution.3. Two kinds of BCB-based siloxane-containing imide monomers were synthesized through imidization between siloxane-containing dianhydride and4-aminoBCB. The obtained BCB monomers exhibited good solubility in organic solvents. The two resins revealed high thermal stability as evidenced by the temperatures of5wt%weight loss at462and468℃, respectively. The cured resins also demonstrated with low dielectric constants (2.7at1MHz) and low-water absorptions. The films prepared from spin-casting the acetic acid solution of BCB monomers showed a well planarization and high transparency. Moreover, the thermal and mechanical properties of the BCB resins could be adjusted by the length of siloxane chain. The resin with a shorter siloxane structure demonstrated higher Tg, higher storage modulus and lower CTE than the longer one.更多还原