An exposure apparatus of the present invention provides a mask having a first space formed by a protection member, which protects a pattern formation area on a mask substrate, and a frame, which supports the protection member, inside a second space, and transfers the pattern of the mask provided in the second space onto a substrate by using an energy beam from a light source. A memory device is provided, according to an aspect of the invention, comprising a floating gate transistor having dual polysilicon floating gates with an isolation opening between floating gates. In some embodiments, there is included a channel region formed by the first gate that is sandwiched by the channel region formed by the second gate, all the channel regions together substantially forming a rectangle or a parallelogram.