Directed Self Assembly (DSA) is an attractive alternative to 193i and multiple patterning. Various polymers were investigated to find the possible structures that can be created with them. Previous research was used to determine the process used. Two surface treatments, a polymer brush and hexamethyldisilazane (HMDS) were used to help the polymers phase separate into their respective structure. The first polymer a polystyrene (PS) block polydimethylsiloxane (PDMS) resulted in de-wetting and film non-uniformity that prevented measurement. The second polymer a PS block polyethylene oxide (PEO) resulted in crystallization if the PEO ratio was too high at 40% mole. When the PEO ratio was low enough at 29% mole and on a PS brush polymer via holes 30 nm in diameter were found using phase imaging on an Atomic Force Microscope (AFM). Repeat samples of the via holes de-wetted from the surface likely due to surface contamination preventing the brush polymer from adhering to the surface.
Bischoff, Paul; Smith, Thomas; Pearson, Robert; and Ewbank, Dale
"Exploration of Directed Self Assembly Polymers,"
Journal of the Microelectronic Engineering Conference: Vol. 21
, Article 3.
Available at: http://scholarworks.rit.edu/ritamec/vol21/iss1/3