A spin coating apparatus and method of manufacturing incorporating a perforated sheet located above the substrate in a manner to control solvent evaporation that tends to occur in the coating vessel when the chuck is rotated without introducing additional airflow complications. The distance between the substrate surface and the perforated sheet, and the number, distribution, and size of the perforations in the perforated sheet can be adjusted to optimize the uniformity of film thickness coating the substrate. The result is reduced substrate and room contamination and enhanced coating uniformity.
A preferred embodiment of the invention provides a method of spin coating a liquid, such as a resist, onto a surface of a substrate. An embodiment of the invention comprises dispensing a liquid onto the surface; spinning the substrate at a first rotational velocity at least until the liquid forms a substantially uniform film on the surface of the substrate; and spinning the substrate at a second rotational velocity in an opposite direction at least until the liquid reforms a substantially uniform film on the surface of the substrate. Other embodiments include a first rotational acceleration for accelerating the substrate to the first rotational velocity, and a second rotational acceleration for accelerating the substrate to the second rotational velocity. Preferably, the second rotational acceleration is much larger than the first rotational acceleration. Still other embodiments include repeating the first velocity, second velocity sequence one or more times.
A preferred embodiment of the invention provides a semiconductor fabrication process. Embodiments include a method for removing contaminating particles from the surface of the wafer, such as in lithography. Embodiments also provide methods for repairing patterning defects caused by particles. The method comprises forming a resist layer over a substrate and a topcoat layer over the resist layer. The method further includes exposing the resist layer, and developing the resist layer a first time. Preferably, developing the resist layer the first time comprises dissolving a first portion of the topcoat layer in the developing solution. Embodiments further include spinning the substrate, developing the resist layer a second time after spinning the substrate. Preferably, developing the resist layer the second time comprises dissolving a second portion of the topcoat layer. Other embodiments provided include a topcoat layer that is insoluble in a developer solution, thereby requiring using a topcoat removal solution.