| 摘要 |
<p>A method for forming a gate electrode of a flash memory device is provided to make a protrusion of an isolation layer have a slope by removing a hard mask pattern by first and second etch processes. A hard mask pattern is formed on a semiconductor substrate(100), having a stack structure composed of a first nitride layer, a first oxide layer, a second nitride layer and a second oxide layer. The semiconductor substrate is etched to form a trench. An isolation layer(109) is formed in the trench, having a protrusion protruding from the semiconductor substrate. While the hard mask pattern is eliminated by an etch process, the upper part of the protrusion of the isolation layer becomes narrower than the lower part of the protrusion. A tunnel oxide layer and a polysilicon layer for a floating gate are formed on the resultant structure including the isolation layer.</p> |
