New Type Of Benzo Cyclobutene (bcb) Monomer Synthesis And Resin Performance Study

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.