| High performance and integration, low power dissipation and high reliability have been the most important indicators and direction for the development of integrated circuit (IC). As the feature size decreased regularly, IC performance such as power dissipation and integration, is continuously optimized. Unfortunately, the resistance-capacitance (RC) coupled delay sharply increases, and it becomes as one of the major obstacles for future promotion of IC performance. So the replacement of traditional Al and SiO2 (k=3.9) respectively with Cu and low-k dielectrics has been the most promising method to solve this problem. As the technology node went through 22nm, the characteristics of low-k dielectrics meet with more challenges. Nowdays, it becomes a hot issue in microelectronics and materials science to develop expected ultralow-k (k<2.0) dielectrics. This paper used a siloxane as precursor, and then add a porogen template. Through spin-coating and pos-annealing treatment, we successfully prepared the ultralow-k porous SiCOH films. The results are summarized as follows:①A 1,2-(bistriethoxysilyl)ethane (BTEE) which has the bridged structure (Si-[C]n-Si) was used as precursor, and a triblock polymer named poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (P123) was added as the porogen. Porous SiCOH films were successfully prepared through sol-gel and spin-on method. This paper evaluated the effects of different molar ratios of P123/BTEE on the structure and performance of porous SiCOH films. When the molar ratio of P123/BTEE came at 0.016, porous SiCOH films exhibited the best comprehensive performance:the films achieved a k value of 1.82, an extremely low leakage current density of 2×10-9A/cm2at 0.5 MV/cm, E of 6.27GPa, and H of 0.58GPa. Furthermore, leakage current mechanism was analyzed on these films. The result shows that leakage current is driven by Schottky emission. Finally, Periodic Mesoporous Organosilicas (PMO) films were successfully synthesized by decreasing the reaction and spin-on speed.② In addition, this paper researched the effect of ultraviolet irradiation (UV) treatment on the electrical properties, moisture adsorption resistance and structure evolution of pores. Before UV treatment, the k value experienced an increase of 12% after moisture adsorption experiment. Besides, the leakage current density at 0.5MV/cm increased from 1.87×10-9A/cm2 to 2.73×10-8A/cm2. However, after UV treatment, the increase of k value was inhibited to less than 4%. Meanwhile, the film kept a very small leakage current density, i.e,1.7×10-9A/cm2@0.5MV/cm. These results should be attributed to the decrease of porosity and pore size due to the UV treatment. Also the CH2 group could be decomposed through UV treatment. All these changes can effectively inhibit the diffusion of H2O.③ Finally, different precursors such as, tetraethoxysilane (TEOS), 1,2-(bistriethoxysilyl)ethane (BTEE), 1,2-(bistriethoxysilyl)methane (BTEM) and 1,2-(bistriethoxysilyl)octane (BTEO) were compared to research the performance evolution of porous SiCOH films. The results indicated that films prepared by BTEE and BTEM exhibited better electrical and mechanical properties than TEOS-resulted films. What’s more, k value increased along with the bridged carbon increased. |
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