| 摘要 |
A method for fabricating a semiconductor device is provided to increase the total length of a channel by simultaneously forming a step gate and a recess gate by two recess processes. A first photoresist layer pattern is formed which defines a step gate region where an impurity junction region in the upper part of a semiconductor substrate(100) protrudes. A predetermined depth of the semiconductor substrate is etched by using the first photoresist layer pattern, and the first photoresist layer pattern is removed to form a step gate region. A second photoresist layer pattern is formed on the resultant structure, defining a recess gate region. A predetermined depth of the semiconductor substrate is etched by using the second photoresist layer pattern as a mask, and the second photoresist layer pattern is removed to form the recess gate region. A predetermined thickness of a gate oxide layer(140) is formed on the resultant structure. A stack structure of a gate polysilicon layer(150), a gate metal layer(160) and a gate hard mask layer(170) is formed on the resultant structure and is etched to form a gate pattern. The recess gate region can be formed at both sides of a step gate region having a type that the impurity junction region in the upper part of the semiconductor substrate protrudes.
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