Specific Process Knowledge/Lithography/Coaters/Spin Coater: RCD8 processing: Difference between revisions
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==Edge bead removal== | ==Edge bead removal== | ||
The automatic dispense system may also be used to administer solvent at the edge of the wafer after spin coating in order to remove the edge bead. Edge bead removal, or EBR, is usually done using PGMEA. Due to the low viscosity of the solvent, and the high pressure of the | The automatic dispense system may also be used to administer solvent at the edge of the wafer after spin coating in order to remove the edge bead. Edge bead removal, or EBR, is usually done using PGMEA. Due to the low viscosity of the solvent, and the relatively high pressure of the EFD control box, it is necessary to use at tip at the end of the syringe. The flow rate of the solvent is a function of the pressure and the size of the tip orifice. While the dispense rate scales roughly linearly with the pressure, it is an exponential function of the tip orifice. | ||
Observed dispense rates of PGMEA (uncertainty from measurements ~0.1 ml/s) for different tip sizes: | Observed dispense rates of PGMEA (uncertainty from measurements ~0.1 ml/s) for different tip sizes: | ||