摘要 |
A method for sidewall etching includes providing a substrate having a trench defined therein, with the trench having fill material disposed over a bottom thereof, along a sidewall thereof, and at the trench opening. The fill material along the sidewall of the trench and at the trench opening is removed without removing the fill material disposed over the bottom of the trench. The fill material along the sidewall and at the trench opening may be removed without removing the fill material disposed over the bottom of the trench by inhibiting a reaction between an etchant and the fill material over the bottom of the trench. The reaction between the etchant and the fill material may be inhibited by causing an air bubble to form at the bottom of the trench. The air bubble may be formed by inverting the substrate, and immersing the inverted substrate in an etchant.
|