| 摘要 |
A method for preparing a bottle-shaped deep trench first forms a first mask with at least one opening on a substrate including a first epitaxy layer, an insulation layer on the first epitaxy layer and a second epitaxy layer on the insulation layer. A first etching process is performed to remove a portion of the substrate under the opening down to the interior of the insulation layer to form a trench, and a thermal treating process is then performed to form a second mask on the inner sidewall of the trench. Subsequently, a second etching process is performed to remove a portion of the substrate under the opening down to the interior of the first epitaxy layer to form a deep trench, and a third etching process is performed to remove a portion of the first epitaxy layer so as to form the bottle-shaped deep trench with an enlarged surface.
|
