US Patent 7459364 Methods of forming self-aligned floating gates using multi-etching

A method of forming a floating gate of a non-volatile memory device can include etching a mask pattern formed between field isolation regions in a field isolation pattern on a substrate to recess a surface of the mask pattern below an upper surface of adjacent field isolation regions to form an opening having a width defined by a side wall of the adjacent field isolation regions above the surface. Then the adjacent field isolation regions is etched to increase the width of the opening.