| 摘要 |
<p>PURPOSE: A method for manufacturing a semiconductor device is provided to reduce the step difference of a high voltage transistor region by forming a step buffering layer with a superior mobility. CONSTITUTION: A trench is formed by etching the high voltage region of a semiconductor substrate. An oxidation process is performed to form a gate insulating film(104) is formed in the trench. A conductive film for a floating gate(105) is formed on a whole structure including the gate insulating film. A step buffering layer(106) is formed on the whole structure including the conductive film for the floating gate in order to reduce the step difference of the high voltage region due to the thickness of the gate insulating film.</p> |
