Theoretical studies of the spin coating process for the deposition of polymer-based Maxwellian liquids

Abstract

This paper deals with the study of spin coating processes for the deposition of polysiloxane-based thin films. Specific developments are proposed in order to adapt the hydrodynamic laws theory to the spin coating of Maxwellian liquids. Theoretical and experimental results are compared, evidencing a good fit and enabling to define the Maxwellian law for the studied polysiloxane polymer. Finally, the theoretical developments are successfully extended to the BCB 4026 and SU-8 3050 photosensitive resins.

Spin-coating process evolution and reproducibility for power-law fluids

“…This is exactly the previously reported solution [7]. In our case, the dimensional analysis arises as a powerful instrument that leads to the solution.…”

“…Charpin et al [6] and, more recently, Temple-Boyer et al [7] presented an exact solution for the thickness profile of power-law fluids during spin coating. Their solution predicts a divergence in the spatial coordinate that forbids uniformity in the center of the plate.…”

Spin casting of dilute solutions: Vertical composition profile during hydrodynamic-evaporative film thinning

“…This "spin casting" process has been investigated since decades. Yet rather few studies (Meyerhofer, 1978;Bornside et al, 1987;Lawrence, 1988Lawrence, , 1990Ohara et al, 1989;Bornside et al, 1989;Shimoji, 1989;Lawrence and Zhou, 1991;Reisfeld et al, 1991aReisfeld et al, , 1991bYonkoski and Soane, 1992;Cregan and O'Brien, 2007;Temple-Boyer et al, 2010;Muench et al, 2011) focused on the evolution of the internal film composition during thinning. They applied different approximations such as "boundary layers" (Lawrence, 1988(Lawrence, , 1990Lawrence and Zhou, 1991) or "split mechanism models" (Yonkoski and Soane, 1992).…”

Three-dimensional closed microfluidic channel fabrication by stepper projection single step lithography: the diabolo effect

“…Such process is quite convenient and allows the creation of SU-8 multilayers 10 . With this method, losses of photoresist products are negligible compared to the conventional deposition process by spin coating 11 . Moreover, it enables a greater control and reliability of the top cover.…”

“…10 With this method, losses of photoresist products are negligible compared to the conventional deposition process by spin coating. 11 Moreover, it enables a greater control and reliability of the top cover. Yet, a lithography step is required for patterning each SU-8 layer meaning that at least two such steps are necessary to fabricate closed microchannels.…”