Modulating the Pattern Quality of Micropatterned Multilayer Films Prepared by Layer-by-Layer Self-Assembly
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- 作者：Jinhan Cho ; Hongseok Jang ; Bongjun Yeom ; Hosub Kim ; Raehyun Kim ; Sangcheol Kim ; Kookheon Char ; and Frank Caruso
- 刊名：Langmuir
- 出版年：2006
- 出版时间：January 31, 2006
- 年：2006
- 卷：22
- 期：3
- 页码：1356 - 1364
- 全文大小：789K
- 年卷期：v.22,no.3(January 31, 2006)
- ISSN：1520-5827
文摘
Patterned multilayer films composed of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate)(PSS) were prepared using dip and spin self-assembly (SA) methods. A silicon substrate was patterned with a photoresistthin film using conventional photolithography, and PAH/PSS multilayers were then deposited onto the substratesurface using dip or spin SA. For spin SA, the photoresist on the substrate was retained, despite the high centrifugalforces involved in depositing the polyelectrolytes (PEs). The patterned multilayer films were formed by immersingthe PE-coated substrates in acetone for 10 min. The effect of ionic strength on the pattern quality in dip and spinmultilayer patterns (line-edge definition and surface roughness of the patterned region) was investigated by increasingthe salt concentration in the PE solution (range 0-1 M). In dip multilayer patterns, the presence of salt increased thefilm surface roughness and pattern thickness without any deformation of pattern shape. The spin multilayer patternsformed without salt induced a height profile of about 130 nm at the pattern edge, whereas the patterns formed withhigh salt content (1 M) were extensively washed off the substrates. Well-defined pattern shapes of spin SA multilayerswere obtained at an ionic strength of 0.4 M NaCl. Multilayer patterns prepared using spin SA and lift-off methodsat the same ionic strength had a surface roughness of about 2 nm, and those prepared using the dip SA and lift-offmethod had a surface roughness of about 5 nm. The same process was used to prepare well-defined patterns oforganic/metallic multilayer films consisting of PE and gold nanoparticles. The spin SA process yielded patternedmultilayer films with various lengths and shapes.