Semiempirical investigation method of silylation reaction mechanism of polyimides photoresist for multilevel–interconnect VLSI technology

Nickolay. G. Savinski ( savinski1-AT-yandex-DOT-ru.gif )
Laboratory of Molecular Electronics, Institute of Microelectronics and Informatics of RAS, 21 Universitetskaya St., Yaroslavl, 150007 Russia.

The low dielectric constant and ease of processing of polyimide materials have resulted in the widespread use of those materials for microelectronic applications, such as passivation coatings, a-particle barriers, and interlayer dielectrics in the manufacture of integrated curcuits. Increasing number of research works was devoted to developing photosensitive polyamides for they can eliminate a number of processing steps, required for patterning of usual polyimide films by using of usual photoresist materials. Developed method polyheterocyclisation of polyamicasids in the presence of the donors of thereemethylsilyl group entirely integrated with technology the fabrications of integrated circuits. Semiempirical quantum mechanics methods appear to be reliable tools for the calculation of the parameters involved in the evaluation of reactivity Polyamic Acids (PAC) with silylation agents. The semiempirical method PM3 was used to determine molecular geometry, charge distribution and the molecular orbital energies, the transition state of reactions PAC with series of silylation agents and to determine the relationship between reactivity and molecular parameters. Semiempirical calculations were produced by original parameters employment of the program PM3, based on the restricted Hartree-Fock (RHF) method. Initial geometries were obtained with molecular mechanics by means of the force fields MM+. The results of three optimizations were employed as impact data for the semiempirical calculations.