A spin coating apparatus, system, and/or method that increase the uniformity of a coating material on a substrate. The spin coating system may be specifically directed for use with polygonal shaped substrates. The spin coating system may include a process chamber within which the substrate is located, spinning on a chuck, during operation. The spin coating system may include gas injection ports that inject a gas into the process chamber so that the gas contacts the substrate along corner portions of its front surface. This injection of the gas increases pressure and prevents excessive build-up of the coating material that may otherwise occur when spin coating polygonal shaped substrates.