Synthsis And Research Of Polyacrylic Acrylate With Low Dielectric Constant

With the rapid development of microelectronic industry, the density of transistors increased with the miniaturization in dimensions of electronic devices. However, the decrease in dimension also generates problems including cross-talk noise, signal delay (RC delay), and power dissipation, which become a bottleneck problem that restrict the development of high efficiency, high speed, low energy consumption, multi-functional electronic products. It is one of the most important keys to settle this problem which is searching for a low dielectric constant materials for the alternative of SiO2 as interlayer insulation material. There are two methods to scale down the dielectric constant of the dielectric layer, to reduce the polarizability in molecule design and to decrease the density of the insulator film. Much attentions paid to the (fluorine-containing)polyimide, (fluorine-containing) poly(aryl ether ketone), and (fluorine-containing) polybenzoxazoles as the low dielectric constant materials, which have excellent mechanical properties and thermal stability attribute to the aromatic ring in polymer main chain. While, this also cause the insoluble and infusible of the polymer, so they couldn’t form a film in simple method. They also have the disadvantages of high cost, dark color, and low yield. We have successfully synthesize a series of fluorine-containing polyacrylic acrylate(FPAA) by two step solution free-radical polymerization and esterification reaction, which can form a film in room temperature, and the dielectric constant, water absorption of the cured films significantly decreased compared with the non-fluorine cured-PAA films.The content and conclusions of are described as follows:(1) A series of fluorine-containing polyacrylic acrylate(FPAA) were successfully synthesized by two step solution free-radical polymerization and esterification reaction. The system of perpolymer with photoinitiator can cured quickly under the UV-irradiation without additional heat.(2) The dielectric constant of the cured film can reaches to 3.23(C2,1 MHz). And the k value of the cured films with the same content of styrene decreased with the increase of the content of fluorine.(3) The glass transition temperature of the amorphous prepolymer were all lower than 0℃, make it possible to form film in room temperature. The thermal stability of the cured films increased with the rise of content of fluorine, T5% and T10% towards to the side of high temperature.(4) The water absorption of the fluorine-containing cured film was in the range of 0.09%-0.71%. The prepolymer have a good solubility in common solvent and compatibility with diluent trimethylpropane triacrylate (TMPTA), and can be patterned with the resolution of 10μm by photolithography.