| 摘要 |
<p>A method for forming a recess gate in a semiconductor device is provided to obtain sufficient overlap margin between a recess gate region and a gate electrode by forming the recess gate using two-step etching. A pad oxide pattern(120) and a hard mask pattern are stacked on a substrate(100) having an isolation layer(110) so as to define a recess gate region. A first recess gate region is formed by etching the substrate using the stacked pattern. A first spacer is formed at both sidewalls of the first recess gate region and the hard mask pattern. A second recess gate region is formed by etching the substrate using the spacer as a mask. An oxide layer is formed by simultaneously oxidizing the second recess gate region and the first spacer. The oxide layer is eliminated, and then a first gate oxide layer is formed by first oxidation processing. After the hard mask pattern and the first gate oxide layer are removed, a second gate oxide layer(190) is formed by second oxidation processing. A recess gate pattern including a polysilicon layer(200), a gate metal film(210) and a gate hard mask(220) is then formed in the second recess gate region. A second spacer(240) is formed at both sidewalls of the recess gate pattern.</p> |
