350 rub
Journal Science Intensive Technologies №11 for 2009 г.
Article in number:
SOL-GEL MESOPOROUS SILICATES FOR VLSI MULTILEVEL INTERCONNECTIONS AND MEMS TECHNOLOGY
Keywords: sol-gel techniques mesaporous silicate alkyl group permittivity porous film heat treatment thermodestruction
Authors:
V. A. Vasiljev, D. S. Seregin, K. A. Vorotilov
Abstract:
Formation processes of nanoporous low-k silicate films for multilayer metallization of VLSI and MEMS technology are studied. It is shown, that thermodestruction of surfactant in silicate polymers is an effective way to obtain ultralow-k nanoporous films with high and homogeneous porosity. As a result of termodestruction of micelles, formed by molecules of сetyl trimethylammonium bromide (CTAB, C16H33N (CH3) Br), mesoporous silicate and organic modified silicate films are prepared. It is established, that introduction of CTAB molecules in a film-forming solution at formation of silicate films results in decrease of refraction index from 1.42 up to 1.28 at the processing temperature of 400°С (within 20 minutes) and formation of a porous microstructure with the relative porosity of 30 %. The increase of heat treatment time of silicate films results in film condensation as a result of polycondensation processes irrespective of CTAB concentration. Introduction of methyl alkyl groups in silicate polymer results in additional decrease of refraction index to the values of 1.23-1.26 and stabilization of this values in all time interval of modes of heat treatment at 400°С. It is established, that the increase of CTAB concentration in an initial solution results in refractive index reduction both for silicate layers and for methyl - modified silicates. The layers prepared from solutions with CTAB concentration in a film-forming solution 0.18 moles on 1 mole of alkoxide, form periodic porous structure (relative porosity of 40 %) with step of 3-4 nm and have dielectric permittivity less than 2.3.
Pages: 37-43
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