Nanostructure formation in spin-cast polystyrene films

✍ Scribed by Shapovalov, Vladimir; Zaitsev, Vladimir S; Strzhemechny, Yuri; Choudhery, Faiqa; Zhao, Wei; Schwarz, Steven A; Ge, Shouren; Shin, Kwanwoo; Sokolov, Jonathan; Rafailovich, Miriam H

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 338 KB
• Volume: 49
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(200005)49:5<432::aid-pi282>3.0.co;2-m

✦ Synopsis

The dependence of spin-cast polystyrene ®lm thickness on silicon substrates is examined as a function of concentration (in toluene) and molecular weight. For uniform ®lms ranging in thickness from 100 A Ê to 1 mm, thickness follows a power law dependence on concentration, with the power varying from 1.25 at low molecular weights, to greater than 2 at the highest molecular weights examined. For very dilute concentrations, atomic force microscopy reveals that the ®lms break up into a uniform distribution of voids or islands with submicron dimensions, as has been observed previously. The apparent ®lm thickness (at molecular weight 690 000), is determined by secondary ion mass spectrometry, and is found to vary linearly with concentration for ®lm thicknesses below $30 A Ê , the thickness at which the ®lm begins to break up. At this molecular weight, X-ray re¯ectivity results indicate that the limiting thickness of the remnant polymer regions is $30 A Ê . Effects of annealing are also investigated.