Pattern Formation by Electric-Field-Induced Dewetting

2 Pattern Formation by Electric-Field-Induced Dewetting 

It was demonstrated that by applying an electrical field to a metastable thin film/ electrostatic pressure could amplify surface fluctuations. This property has been used to tune the size of the self-assembled structures from micron to submicron scale in electrically induced dewetting. Furthermore the possibility to apply a sufficiently strong electric field in defined regions allows the fabrication of a variety of patterns controlling size and positioning.  

In their work the authors proved that by increasing the electrical field up to a threshold value, the surface waves are amplified until the formation of polymer pillars. Evidence for both nucleated and 

As PS pillars grow, circular rims around the pillars where an unstable PMMA thin film is exposed to the air are formed. At this point a second instability upon the electrical field occurs at the PMMA-air interface. PMMA dewets from the silicon surface, reorganizing around the PS pillars (Fig. 14.12b). The final morphology consists of PS columns coated by a thin layer of PMMA (Fig. 14.12c). 

At the end of the process, a thin layer of PM MA remains, covering the entire substrate. As it is shown in Fig. 14.13b the method was extended from pillars to lines. 

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