Semiconductor memory device having a floating gate and method of manufacturing the same

摘要

A semiconductor memory device having a floating gate and a method of manufacturing the same, where a conductive layer for a floating gate is deposited on a semiconductor substrate and etched to form a conductive layer pattern. An annealing of the semiconductor substrate is carried out in an ambient atmosphere of hydrogen gas. Alternatively, an entire surface of the conductive layer pattern is etched by a dry etching method or a wet etching method. As a result, at least one edge of the conductive layer pattern is rounded, which reduces the likelihood that an electric field is concentrated at the edge and reduces a likelihood that the dielectric layer formed on the floating gate is thinner at the edge.