The Preparation And Characterization Of Porous Low Dielectric Constant Oligomeric-MSSQ Films

As integrated circuit (IC) dimensions continue to decrease, resistance-capacitance (RC) delay, crosstalk noise, and power dissipation of the interconnect structure become limiting factors for ultra-large-scale integration (ULSI) of integrated circuits. To meet the continuing development of IC industry, the ever increasing requirements for electrical performance of on-chip wiring have driven three major technological advances in recent years. First, Copper has replaced Aluminum as the new interconnect metal of choice. Second, alternatives for SiO2 with a lower dielectric constant are being developed and introduced in main stream processing. Third, in an attempt to lower the dielectric constant even more, porosity is being introduced into these new materials. In this thesis, starting from fabricating porous low dielectric constant oligomeric methyl silsesquioxane (O-MSSQ) thin films, introduction of tetradecane an ideal pore generator into O-MSSQ thin films first plays an obvious role in lowering the dielectric constant of O-MSSQ films. And material properties of low-k dielectrics are discussed. The main contents and results of this paper consist of the following points:(1)The basic require of low dielectric materials were summarized. MSSQ-based materials are the best of promising materials by comparing with multi- materials which reduce dielectric constant. The porous low dielectric constant O-MSSQ films were prepared by using SOG—Spin-on glasses, and the effects of reaction temperature, PH and molar ratio of H2O to MTMS(R)were discussed. The best reaction condition was found. Then, the chemistry structure of O-MSSQ was synthesized and characterized by FTIR and 1H-NMR. Different experiment conditions play a role in the chemistry structure.(2)This is followed by a description of the experiment data of bringing porosity into the organic-inorganic compound material and analyzing the effects of different porosity. The electrical property of the dielectric constant and dielectric loss of O-MSSQ films were studied. The results suggest that the porous low dielectric constant O-MSSQ films were 1.9, and it is a typical low-K material. The best density percentage of tetrandecane was found. Thermogravimetric Analysis (TGA) was also measured.(3)Surface and cross section morphology of porous O-MSSQ films were investigated by AFM and SEM. The size and distributing of pore were studied. Finally, Adhesion strength of the films was measured.