Methods of fabricating integrated circuit devices are provided using composite spacer formation processes. A composite spacer structure is used to pattern and etch the layer stack when forming select features of the devices. A composite storage structure includes a first spacer formed from a first layer of spacer material and second and third spacers formed from a second layer of spacer material. The process is suitable for making devices with line and space sizes at less then the minimum resolvable feature size of the photolithographic processes being used. Moreover, equal line and space sizes at less than the minimum feature size are possible. In one embodiment, an array of dual control gate non-volatile flash memory storage elements is formed using composite spacer structures. When forming the active areas of the substrate, with overlying strips of a layer stack and isolation regions therebetween, a composite spacer structure facilitates equal lengths of the strips and isolation regions therebetween.