A backlight system in accordance with the present invention includes a plurality of light sources for emitting light beams and a light guide plate for receiving the light beams emitted by the light sources. Mixtures comprising: glycol; antioxidant; and defoamer. Layout analysis enumerates all of the windows within the interface and extracts the position values of each window and the dimension values of each window to form a set of layout information. In particular, the likewise substantially transparent for X-ray radiation. By such a configuration, an exposure method by which when exposing edge areas of the substrate, the exposure can be performed in a condition that a liquid immersion region is formed well and that flowing out of the liquid to the outside of the substrate stage are prevented is provided.