Preparation And Characterization Of Polymer LB Films For Lithography

A series of N-alkylacrylamide, including N-dodecylacrylamide (DDA), N-dodecylmethacrylamide (DDMA), N-hexadecylacrylamide(HDA) andN-hexadecylmethylacrylamide (HDMA) were synthesized for the use of film-forming materials of resists. 1,4-dioxaspiro[4,4]nonane-2-methyl methacrylate(DNMMA), which has functional group on molecules, was synthesized as the photosensitive part of LB films. Copolymerization of N-alkylacrylamide and DNMMA were carried out for the research of forming LB films.N-alkylacrylamide, including DDA, DDMA, HDA, HDMA, is a kind of amphiphiles which have long alkyl chains, and they have the ability of forming stable films. The influence of different conditions on Langmuir film at air/water interface and the difference between the π — A isotherms of monomers and corresponding homopolymers was investigated. Copolymers with different molar ratio were synthesized and their π—A isotherms were made, the results show that when the proportion of the two monomers was 1:1, steeper curve and higher collapse pressure of π-A isotherm would be obtained. The changes of elasticity of monolayer at air/water interface depending on the surface pressure were studied and it was found that when the monolayer at air/water interface is in the "solid phase", the elasticity could reach a maximum.UV-vis spectrophotometer was used for measuring the absorbance of LB films which were deposited onto quartz substrates and have the number of layers as 22, 42, 62, 82, separately, to insure whether the LB films were deposited homogeneously. It can be found that the absorbances at 193 nm are proportional to the number of layers at least up to 82 layers. The liner relationship between the absorbance and the number of layers suggests that a regular deposition of the copolymer monolayer take place, resulting in a fairly uniform LB films.The topography of LB films was investigated by atomic force microscopy (AFM). The result showed that copolymer could form condensed and consecutive LB monolayer on mica substrate. Besides, on several nanometer scales, the arrangement of backbone chains could be seen, but the state on several hundred nanometer scopes was disordered. This was improved...