Methods for fabricating nonvolatile memory device

摘要

Methods of fabricating a nonvolatile memory device are disclosed. A disclosed method comprises forming a first buffer oxide layer and a first buffer nitride layer on a semiconductor substrate; forming an opening through the first buffer nitride layer and the first buffer oxide layer; forming sidewall floating gates on sidewalls within the opening; forming a block oxide layer; forming a polysilicon main gate over the sidewall floating gates; forming first sidewall spacers on the sidewalls of the polysilicon main gate and the sidewall floating gates; forming common source and drain regions in the semiconductor substrate; filling the gap between the polysilicon main gates with an insulating layer; depositing a polysilicon layer for a word line; patterning a word line and the polysilicon main gate in the direction of a word line; and forming second sidewall spacers on the sidewalls of the word line and the polysilicon main gate.