US Patent 7915118 Nonvolatile memory devices and methods of fabricating the same

A nonvolatile memory device may include a semiconductor substrate, a floating gate electrode on the semiconductor substrate that includes an acute-angled tip at an upper end, and a control gate electrode insulated from the floating gate electrode and facing at least a portion of the floating gate electrode, wherein an angle formed between the semiconductor substrate and an upper portion of a lateral surface of the floating gate electrode is smaller than an angle formed between the semiconductor substrate and a lower portion of the lateral surface of the floating gate electrode.