METHOD FOR FORMING TRENCH OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a trench of a semiconductor device is provided to secure the process margin for the mis-alignment of a contact pattern by forming a spacer in the middle of a two-step etching process for the trench. CONSTITUTION: A pad oxide and a nitride layer(12,13) are sequentially formed on a semiconductor substrate(11). The first trench is formed in the substrate by selectively etching the resultant structure. A liner layer is formed along the upper surface of the resultant structure. The substrate is partially exposed by carrying out an etch-back process on the liner layer. At this time, a spacer(15') is formed at both sidewalls of the first trench. The second trench is formed by etching the exposed substrate through the first trench. An insulating layer(16) is formed on the entire surface of the resultant structure for completely filling the trench.