| 摘要 |
A method for forming a recess channel trench of a semiconductor device is provided to improve the uniformity of device characteristics, to restrain the generation of leakage current due to junction and to improve refresh characteristics by obtaining a curved portion from the recess channel trench using two-step etching processes. An insulating layer and a hard mask layer are sequentially formed on a semiconductor substrate(200). A photoresist pattern for exposing a predetermined region of the hard mask layer to the outside is formed thereon. A hard mask pattern and an insulating pattern are formed on the resultant structure by an etching process using the photoresist pattern as an etch mask. At this time, the substrate is partially exposed to the outside. A first recess channel trench is formed on the exposed substrate by first etching using the hard mask pattern as an etch mask. An oxide layer is formed along an upper surface of the resultant structure. A sidewall oxide layer is formed at both sides of the first recess channel trench by etching selectively the oxide layer. A second recess channel trench(310) is formed under the first recess channel trench by second etching using the sidewall oxide layer as an etch mask.
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